MTTP/ATC/CONTRACT

Purpose

This contract establishes the air traffic communication procedures, radio phraseology, and pilot and controller compliance duties used at SOURCE, where real people crew both the aircraft and the air traffic control positions. It adapts 95 source paragraphs of the FAA Aeronautical Information Manual (AIM) for that environment, using real-world phraseology throughout. It is organised into five chapters: Chapter 1, Air Navigation; Chapter 2, Airport Signs and Markings; Chapter 3, Airspace; Chapter 4, Air Traffic Control Services and Procedures; and Chapter 5, Air Traffic Procedures.

Scope

This contract covers navigation-aid use and procedures; pavement-marking and airport-sign interpretation; airspace classification and its associated equipment, communication and weather-minimum rules; Air Traffic Control services, radio phraseology, airport operations, and clearance and separation standards; and the preflight, departure, en route and arrival procedures a pilot follows on an IFR or VFR flight, each adapted from the corresponding chapter of the source AIM. It applies without regard to operator category: civil, general aviation, military, formation and airline traffic are all within scope, and no paragraph should be read to assume civilian-only or general-aviation-only operations unless it states that assumption explicitly.

This contract does not cover FAA legal or certificate-action processes; real-world accident or incident investigation or NTSB reporting procedures; administrative or paperwork content with no radio-communication or in-flight-procedure relevance; or real-world equipment certification and maintenance content with no operational relevance. These are outside the simulated environment and outside this contract regardless of whether the underlying AIM section addresses them. Where a source AIM section or subsection was not among the 95 paragraphs adapted into this contract, the corresponding chapter's own Scope section states that gap; where a paragraph needs to point at the missing content, it cites the source AIM designator directly (for example, "AIM 3-2-3") rather than restating or fabricating the missing content.

A cross-reference to a paragraph included in this contract, whether in the same chapter or a different one, cites this contract's own chapter-and-paragraph number together with the paragraph's title (for example, "paragraph 5.22, Approach Control"). A cross-reference to source AIM content not adapted into this contract cites the source AIM designator directly (for example, "AIM 4-3-15") and states that the material is outside this contract's scope. A cross-reference to a real-world statute or regulation (for example, 14 CFR § 91.155) is cited directly and is not restated.

Applicability

This contract applies to every pilot and every controlling facility (Flight Service Station, Clearance Delivery, Ground, Tower, Departure, Approach or Center) operating at SOURCE, under Visual Flight Rules (VFR), Defense VFR (DVFR) or Instrument Flight Rules (IFR), and to civil, general aviation, military, formation and airline traffic alike.

Modal verbs

This contract uses MUST, MUST NOT, WILL, SHOULD and MAY with fixed meanings, applied consistently across every chapter.

Verb	Meaning
MUST / MUST NOT	States a mandatory requirement or prohibition, with no exception unless one is stated in the same sentence.
WILL	States standard procedure: what an actor does as a matter of course.
SHOULD	States a recommended practice that leaves judgement to the actor.
MAY	Grants a permission whose exercise is optional; not acting on it is equally compliant.

Conventions

This contract assumes a reader already familiar with routine radio communication procedures and does not restate them.

Each chapter's top-level paragraphs are numbered with that chapter's own number as a prefix, so Chapter 4's paragraphs run 4.1 through 4.41. A citation to a sub-paragraph takes the form chapter.paragraph.letter.(number), for example 5.21.k.(2). Every top-level paragraph carries a link anchor of the form #p4.26, which is what the pointers on the ATC Radio Handbook and ATC Communication Flows pages link to.

A term used across more than one chapter is defined once, in the Glossary at the foot of this page. Where a paragraph's own "Controlled Terms" subparagraph is present, it defines only the terms local to that paragraph.

Three inline tags mark places where a rule is not settled, and they are deliberately absent from the two derived pages:

An inline [VERIFY: …] tag marks a point where the source material was ambiguous, or could not be confirmed with confidence, and should be checked against a current AIM edition or SOURCE's own procedures before being briefed as settled.
A (briefed every mission) tag marks a point where no standing default exists and the applicable value or procedure is instead set by the mission briefing.
A (discretion) or (at [an actor's] discretion) tag marks a point where the source material itself leaves the matter to judgement, with no standard to apply.

Illustrative values used in examples (call signs, frequencies, altitudes, fix names, headings) are generic placeholders and are not asserted as real-world or SOURCE-published values unless a paragraph states otherwise.

Summary of changes

Initial publication. This contract adapts 95 source paragraphs of the FAA Aeronautical Information Manual (AIM), spanning AIM Chapters 1 through 5, into five chapters. In assembling it: each chapter's top-level paragraphs were numbered under one chapter-prefixed scheme (this document's own paragraph numbers, for example "4.6" or "5.21", replacing the bare per-chapter numbering carried by earlier working drafts); cross-references between chapters were resolved to cite this contract's own paragraph numbers and titles rather than raw AIM source citations, except where the cited material was never adapted into this contract, in which case the raw AIM citation is retained and marked as outside this contract's scope; and each chapter's separately stated Applicability, Modal Verbs and User Information were consolidated into this preface, with each chapter's own Glossary entries consolidated into the Glossary at the foot of this page. No operational rule stated in an individual chapter was added or changed by that consolidation.

Chapter 1 — Air Navigation

Purpose

This chapter establishes the navigation aids and performance-based navigation procedures a pilot uses, in coordination with Air Traffic Control (ATC), to fly instrument and visual routes: ground-based facility composition and identification, distance-measurement interpretation, instrument approach flying and critical-area protection, satellite-based navigation and integrity monitoring, and area-navigation compliance. This chapter does not cover general airspace classification or radio communications phraseology, which are addressed elsewhere in this contract.

1.1 VHF Omnidirectional Range/Tactical Air Navigation (VORTAC) Facilities and Procedures

This paragraph establishes the composition, identification, and pilot procedures for a VHF Omnidirectional Range/Tactical Air Navigation (VORTAC) facility, the combined ground-based navigation aid that provides azimuth and distance service to both VOR/Distance Measuring Equipment (DME)-equipped and TACAN-equipped aircraft from a single site.

a. VORTAC Facility Composition

(1) At each VORTAC facility, the facility will provide three individual navigation services from a single site, listed in Table 1.

TABLE 1. VORTAC Services

Item	Service	Reference Type	Typical User Equipment
1	VOR azimuth	Bearing	VOR receiver
2	TACAN azimuth	Bearing	TACAN receiver
3	TACAN distance (DME)	Distance	TACAN receiver or DME interrogator

Legend: DME = Distance Measuring Equipment; TACAN = Tactical Air Navigation; VOR = VHF Omnidirectional Range.

Note: A VOR-equipped aircraft receives only the azimuth service in Item 1. A TACAN-equipped aircraft receives both the azimuth and distance services in Items 2 and 3. Both aircraft reference the same ground station.

b. Facility Identification

(1) At each VORTAC facility, the VOR and TACAN transmissions will carry one shared three-letter Morse code identification.

Note: Because the identification is interlocked, a pilot using VOR azimuth and a pilot using TACAN distance from that facility are each assured both signals originate from the same ground station.

(2) At each VORTAC facility, the VOR frequency and its paired TACAN channel will be assigned together under a national channeling plan.

Note: Under the paired channeling plan, a pilot tuned to the charted VOR frequency and a pilot selecting the charted TACAN channel at that facility are each using the reference published for their own equipment, without separately cross-referencing the other system's frequency or channel.

Example: Direct-To Clearance via VORTAC

Condition: Approach clears an aircraft direct to a fix associated with a VORTAC.

Speaker	Transmission
Approach	"N123AB, GOLF VORTAC, direct, when able."
Pilot	"Direct GOLF VORTAC, N123AB."

Required response: The pilot reads back the facility name and confirms own aircraft identification.

Example: Mixed-Equipment Identification Check

A civil aircraft tunes VOR frequency 115.7 MHz at GOLF VORTAC and hears the three-letter identifier "GLF." A TACAN-equipped military aircraft in the same flight selects the paired TACAN channel 104X and hears the identical identifier "GLF." Because both idents match, each pilot confirms that the VOR azimuth and the TACAN azimuth/distance references come from the same ground station.

c. TACAN Airborne Equipment

(1) When receiving navigation guidance from a VORTAC facility in an aircraft equipped with TACAN, the pilot will tune the assigned TACAN channel on the aircraft's dedicated TACAN receiver, not a VOR frequency.

Note: A conventional VOR receiver cannot process the TACAN signal, which is a pulse signal transmitted in the Ultrahigh Frequency (UHF) band; TACAN reception requires dedicated TACAN airborne equipment separate from the VOR receiver.

d. TACAN Channel Assignment

(1) When directing a pilot operating a TACAN-equipped aircraft to navigate from a VORTAC facility, ATC (Approach or Center (Air Route Traffic Control Center, ARTCC)) will state the facility's TACAN channel number rather than a VOR frequency.

(2) The pilot will read back the assigned TACAN channel number.

Example: TACAN Channel Assignment

Approach: "Ghost Flight, change to TACAN channel 083, Springfield VORTAC."

Ghost Flight: "Channel 083, Ghost Flight."

Note: A pilot operating an aircraft equipped only with conventional VOR/DME receives course and distance information from the same VORTAC facility by VOR frequency, and ATC does not assign that aircraft a TACAN channel.

1.2 Distance Measuring Equipment (DME)

This paragraph establishes how a pilot interprets range information from Distance Measuring Equipment (DME), the airborne-to-ground pulse system that pairs with VOR, TACAN, Instrument Landing System (ILS), and localizer (LOC) facilities to provide distance in addition to course guidance.

a. Slant Range Distance

(1) When reading a DME distance display, the pilot will treat the displayed value as slant range distance (the straight-line distance from the aircraft to the ground station), not as horizontal distance over the ground.

Note: DME accuracy is better than 0.5 nautical miles (NM) or 3 percent of the displayed distance, whichever is greater, for reliable signals out to 199 NM at line-of-sight altitude. Slant range reads highest relative to horizontal distance when the aircraft is close to and above the ground station.

Example: Position Report Using DME Distance

Condition: A pilot reports position to Center using DME distance from a named facility.

Pilot: "Center, Reach three one, two five DME west of Ranger VORTAC, flight level two three zero."

Center: "Reach three one, Center, roger."

b. TACAN-Derived Distance

Where the aircraft carries TACAN equipment, the aircraft will derive distance automatically from a VORTAC facility (established in paragraph 1.1) without separate pilot selection.

c. VOR-Only DME

Where the aircraft carries VOR equipment without TACAN, the pilot will have a separate DME unit installed and selected to receive distance from a facility.

d. Siting Offset

At a military VOR facility and TACAN facility serving the same area but not collocated, the pilot should account for a siting offset of up to a few miles between the course source and the distance source.

Note: Frequency pairing between a VOR facility and a TACAN facility does not guarantee that the two share one location.

e. Identification Tones

When identifying a VOR/DME, VORTAC, ILS/DME, or LOC/DME facility by ear, the pilot will distinguish the course identifier from the distance identifier per Table 2.

TABLE 2. DME and TACAN Identification Tones

Item	Component	Tone Frequency	Transmission Pattern
1	VOR or LOC	1020 Hz	Sent 3 or 4 times per 1 DME/TACAN identification
2	DME or TACAN	1350 Hz	Sent once per 3 or 4 VOR/LOC identifications

Legend: DME = Distance Measuring Equipment; TACAN = Tactical Air Navigation; VOR = VHF Omnidirectional Range; LOC = localizer; Hz = hertz.

f. Single-Tone Failure Indication

When only one coded identification is audible with a repetition interval of approximately 30 seconds, the pilot must recognize that the DME or TACAN component alone is operative and that the VOR or localizer component has failed. When both coded identifications are audible on their normal shared time-share pattern, both components are operative.

g. Automatic DME Pairing Limitation

When a VOR or ILS facility without an installed DME feature is selected by the aircraft's automatic DME-pairing logic, the pilot must disregard any distance display the aircraft presents for that facility.

Note: Automatic DME pairing normally assures that azimuth and distance come from one common source when a VOR/DME, VORTAC, ILS/DME, or LOC/DME facility is selected. That assurance does not hold when the selected facility has no DME feature installed.

1.3 Instrument Landing System (ILS)

This paragraph establishes Instrument Landing System (ILS) glide path flying procedures, approach minimums, inoperative-component handling, and critical area protection responsibilities between ATC and the pilot.

a. Localizer and Glide Path

(1) When flying the back course of a localizer whose receiver lacks reverse-sensing capability, the pilot must steer the aircraft opposite the needle deflection to correct from off-course to on-course.

(2) On intercepting the glide path, the pilot must watch for false courses and reversed needle sensing at angles above the published glide path angle.

(3) The pilot must not descend below the published glide path.

Note: Descending below the published glide path forfeits obstacle and terrain clearance.

Note: The published Threshold Crossing Height (TCH) does not represent the glide path indication height at the runway threshold; the pilot accounts separately for the vertical distance between the glide slope antenna and the main gear.

b. ILS Approach Minimums

(1) The lowest authorized Category I ILS minimums, with all systems operative, are a Decision Height (DH) of 200 ft above touchdown zone elevation and a Runway Visual Range (RVR) of 2,400 ft.

(2) Category II and Category III minimums authorize progressively lower DH and RVR, down to no DH and no RVR limit for Category IIIc, and require special authorization and equipment briefed every mission.

c. Inoperative Components

(1) When the localizer is inoperative, the pilot must not fly the procedure as an ILS approach.

(2) When the glide slope is inoperative, the pilot will fly the procedure as a non-precision localizer approach.

Note: Minimums adjustments for inoperative airborne or ground equipment are published in the Terminal Procedures Publication (TPP).

d. ILS Critical Areas

(1) When the ceiling is 800 ft above ground level (AGL) or higher and visibility is 2 statute miles (SM) or greater, ATC will not protect the localizer or glide slope critical area unless the pilot specifically requests protection.

(2) When the ceiling is below 800 ft AGL or visibility is below 2 SM, ATC will not authorize holding below 5,000 ft AGL between the Outer Marker (OM) and the airport.

Note: Holding traffic in that area can distort localizer signals for aircraft flying the ILS.

(3) Under the weather condition in (2), once an arriving aircraft is inside the OM, the following apply:

 (a) ATC will not authorize another aircraft or vehicle into the localizer critical area, except that a preceding arriving aircraft may cross over it and a preceding departing or missed-approach aircraft may cross through it.

 (b) ATC will not authorize any aircraft or vehicle into the glide slope critical area unless that arriving aircraft has the runway in sight and is circling or side-stepping.

(4) When, in addition to (2), the ceiling is below 200 ft AGL or the RVR is below 2,000 ft and the arriving aircraft is inside the Middle Marker (MM) or ½ NM final, ATC will not authorize a preceding arriving, departing, or missed-approach aircraft to cross the localizer critical area, without the exception in (3)(a).

(5) Before conducting an autoland operation or using SA Category I, II, or III minimums when the official weather observation shows a ceiling of 800 ft AGL or higher and visibility of 2 SM or greater, flight crews should advise the tower.

Example: Autoland Critical Area Advisory

Pilot to Tower: "Denver Tower, United One One Five Three, Request Autoland, Runway [number]."

Tower to Pilot: "United One One Five Three, Denver Tower, Roger, Critical Areas Not Protected."

Note: Even when critical areas are protected, ATC may still authorize a preceding aircraft to cross the localizer critical area unless the official weather observation, including a controller observation, shows a ceiling below 200 ft AGL or RVR below 2,000 ft. Vehicular traffic not subject to ATC may cause momentary course or glide path deviation. Critical areas are unprotected at uncontrolled airports and at towered airports above the thresholds in (1).

1.4 Global Positioning System (GPS)

This paragraph establishes pilot and ATC responsibilities for Global Positioning System (GPS) navigation, including waypoint identifiers used in radio communication, equipment-outage reporting, and required pilot action when Receiver Autonomous Integrity Monitoring (RAIM) is lost during an instrument approach.

a. VFR Navigation

On any flight conducted under Visual Flight Rules (VFR), the pilot must not rely solely on GPS for navigation. The pilot should cross-check GPS position against pilotage, dead reckoning, or other electronic navigation throughout the flight.

b. VFR Waypoint Identifiers

When transmitting a position report to ATC, the pilot must not use a stand-alone VFR waypoint identifier, a five-letter code beginning with "VP." A VFR waypoint collocated with a charted visual checkpoint uses the checkpoint's pronounceable name, and the pilot may use that name in a radio call to ATC.

Example: VFR Waypoint Position Report

Pilot (crossing a charted visual checkpoint): "Approach, November One Two Three Alpha Bravo, over Twin Lakes, request flight following."

Approach: "November One Two Three Alpha Bravo, radar contact, [altitude]."

c. Computer Navigation Fixes

When communicating with ATC by radio or filing a flight plan, the pilot must not reference a Computer Navigation Fix (CNF). ATC does not recognize or maintain CNFs.

d. Alternate Navigation and RAIM Monitoring

When flying under Instrument Flight Rules (IFR) with unaugmented GPS equipment, the pilot must carry an approved alternate navigation means suitable for the route flown. Once RAIM capability is lost, the pilot must actively monitor that alternate means. Active monitoring is not required while RAIM continues to provide integrity monitoring.

e. Equipment Suffix and Failure Reporting

When filing an ATC flight plan, the pilot must enter the equipment suffix that corresponds to the aircraft's installed navigation capability. When the GPS receiver becomes inoperative in flight, the pilot should advise ATC of the failure. The pilot should also amend the filed equipment suffix.

f. RNAV (GPS) Approach Procedure

When cleared by ATC for an RNAV (GPS) approach, the pilot should fly the full published procedure beginning at the Initial Approach Waypoint (IAWP) or a feeder fix rather than joining at an intermediate fix.

g. Approach Mode Arming

Once within 30 NM straight-line distance of the airport or heliport reference point, the pilot should arm the GPS receiver's approach mode not later than the receiver's 30 NM arm annunciation, if not already armed.

h. RAIM Failure During Approach

If the GPS receiver fails to sequence into approach mode, or if a RAIM failure or status annunciation occurs before the Final Approach Waypoint (FAWP), the pilot must not initiate the approach or descend. The pilot must instead fly via the FAWP to the Missed Approach Waypoint (MAWP) and execute the missed approach procedure. The pilot must then contact ATC as soon as practical. If a RAIM failure or status annunciation occurs after the FAWP, the pilot should climb and execute the missed approach procedure.

Example: RAIM Failure Missed Approach

Pilot (RAIM failure annunciated prior to the FAWP): "Approach, November One Two Three Alpha Bravo, GPS RAIM failure, executing the missed approach."

Approach: "November One Two Three Alpha Bravo, roger, fly published missed approach, climb and maintain [altitude]."

i. Preflight RAIM Information

During a preflight briefing, the pilot may request GPS RAIM aeronautical information from the Flight Service Station (FSS) for the departure, destination, or alternate airport. The FSS will provide RAIM information for the 1-hour period before through the 1-hour period after the pilot's estimated time of arrival (ETA), unless the pilot requests a different time frame.

Note: At a military airfield, the military provides GPS RAIM outage information for nonprecision approach procedures as an M-series Notice to Airmen (NOTAM), obtainable for up to 24 hours after the pilot's request. This is separate from the civil process established in paragraph 1.4.i.

1.5 Performance-Based Navigation and Area Navigation (PBN/RNAV)

This paragraph establishes pilot responsibilities under Performance-Based Navigation (PBN) and Area Navigation (RNAV): navigation-specification compliance, waypoint sequencing, leg-type interpretation, and sensor suitability. It does not cover procedure design criteria, which are published on the applicable charted procedure.

a. PBN and Navigation Specifications

PBN is the umbrella concept under which all RNAV operations are conducted. PBN comprises two categories: RNAV, and Required Navigation Performance (RNP), which adds onboard performance monitoring and alerting to the RNAV baseline. Where a charted procedure or an ATC clearance specifies a navigation specification (NavSpec), such as RNAV 1, RNAV 2, RNAV 10, or an RNP designation, pilots must fly that NavSpec's accuracy standard. A NavSpec's numeral states the lateral navigation accuracy, in NM, that the aircraft's system must maintain at least 95 percent of the flight time.

Note: Detailed accuracy and monitoring criteria for each NavSpec are published in International Civil Aviation Organization (ICAO) Document 9613 and Federal Aviation Administration (FAA) Advisory Circular 90-105.

b. Area Navigation Capability

Within the limits of the aircraft's equipage, pilots may use ground-based navigation aids, space-based navigation aids, a self-contained navigation system, or a combination of these to fly an RNAV-defined flight path.

c. Waypoints

A waypoint is a predetermined geographic position, defined by latitude and longitude, that marks a course, speed, or altitude change on a charted procedure. When a procedure designates a fly-by waypoint, pilots will begin the turn toward the next course before reaching that waypoint so as to join the succeeding leg without overflying it. When a procedure designates a fly-over waypoint, pilots must fly over that waypoint before beginning any turn toward the next course.

d. RNAV Departure Clearance

Before releasing an aircraft on a charted RNAV departure procedure, Clearance Delivery will state the procedure's full name and its NavSpec designation in the initial clearance.

Example: RNAV Departure Clearance Readback

Clearance Delivery: "REDEYE ONE ONE, CLEARED TO METRO AIRPORT VIA THE [PROCEDURE NAME] DEPARTURE, RNAV ONE, MAINTAIN FIVE THOUSAND, EXPECT ONE ZERO THOUSAND ONE ZERO MINUTES AFTER DEPARTURE, DEPARTURE FREQUENCY ONE THREE FOUR POINT FIVE, SQUAWK ZERO TWO ONE SEVEN."

Pilot: "CLEARED TO METRO VIA THE [PROCEDURE NAME] DEPARTURE, RNAV ONE, MAINTAIN FIVE THOUSAND, ONE THREE FOUR POINT FIVE, SQUAWK ZERO TWO ONE SEVEN, REDEYE ONE ONE."

Note: The readback confirms the pilot's acceptance of the charted NavSpec and, by extension, the fly-by and fly-over waypoint sequence coded into that procedure (established in paragraph 1.5.c).

e. RNAV Leg Types

Charted RNAV procedures will specify each leg's desired path and termination point using a two-letter leg-type code: Track to Fix (TF), Direct to Fix (DF), Course to Fix (CF), Radius to Fix (RF), or a heading-based leg type. Before accepting a clearance for a charted RNAV procedure, pilots should confirm that their aircraft's navigation system supports every leg type coded on that procedure.

f. Navigation Sensor Suitability

A Flight Management System (FMS) computes the aircraft's RNAV position from sensor inputs that may include GPS/Wide Area Augmentation System (WAAS), DME/DME, VOR/DME, and inertial reference systems. Pilots should monitor the suitability of these sensor inputs for the assigned NavSpec throughout the flight.

TABLE 3. RNAV Navigation Specifications (NavSpecs)

NavSpec	Application	Required Lateral Accuracy
RNAV 1	Departure Procedures (DPs) and Standard Terminal Arrivals (STARs)	1 NM, 95% of flight time
RNAV 2	En route operations	2 NM, 95% of flight time
RNAV 10	Oceanic operations	10 NM, 95% of flight time

Legend: NM = nautical miles; DP = Departure Procedure; STAR = Standard Terminal Arrival.

References

AIM 1-1-5, Tactical Air Navigation (TACAN); AIM 1-1-6, VHF Omni-directional Range/Tactical Air Navigation (VORTAC); AIM 1-1-7, Distance Measuring Equipment (DME); AIM 1-1-9, Instrument Landing System (ILS); AIM 1-1-17, Global Positioning System (GPS); AIM 1-2-1, General.

Chapter 2 — Airport Signs and Markings

Purpose

This chapter establishes, for the sim pilot, the standard for interpreting pavement markings and airport signs at network airports, and the radio procedure to follow when a marking's or sign's meaning cannot be identified.

Scope

This chapter covers pavement marking and airport sign interpretation for pilots operating at network airports, and the call for requesting clarification of a marking or sign whose meaning cannot be identified. Negative scope is established in paragraph 2.1.

This chapter is derived solely from Aeronautical Information Manual (AIM) 2-3-1, General. Other AIM 2-3 subsections addressing specific pavement marking and sign designs are not within this contract's current scope.

2.1 Airport Signs and Markings

This section establishes that pavement markings and airport signs are standardized across the network and states what each pilot does on encountering one whose meaning cannot be identified. It does not cover facility-level correction of marking or sign deficiencies or any non-radio reporting of airport discrepancies; those are outside this contract.

a. When operating at any airport in the network, each pilot WILL interpret pavement markings and airport signs according to the standard meanings published for the network's airports.

Note: Marking and sign standards are uniform across the network's airports, so no airport-specific briefing on sign or marking meanings is required before a mission.

b. On encountering a pavement marking or airport sign whose meaning the pilot cannot identify, the pilot SHOULD hold current position, if not yet cleared onto a runway, and request clarification from Ground.

Note: If the pilot is already in contact with Tower when the marking or sign in question is encountered, for example on a runway or during landing rollout, the pilot requests clarification from Tower instead of Ground.

Example: Requesting Clarification of Unclear Taxiway Signage

Pilot: "Ground, Viper Two One, holding short of taxiway Bravo, unable to identify taxiway signage, request progressive taxi instructions to parking."

Ground: "Viper Two One, Ground, taxi via Bravo, Charlie, to parking, hold short runway two seven."

References

AIM 2-3-1, General.

Chapter 3 — Airspace

Purpose

This chapter establishes how the National Airspace System (NAS) is classified into airspace classes (Class A, Class B, Class C, Class D, Class E, and Class G) and states the equipment, two-way radio communication, clearance, and weather-minimum rules that apply to each pilot operating an aircraft under visual flight rules (VFR) or instrument flight rules (IFR) within each class. This chapter also establishes rules for special use airspace, specifically prohibited areas, restricted areas, and Military Operations Areas (MOAs), and for Military Training Routes (MTRs).

Scope

This chapter does not establish air traffic control (ATC) clearance-request phraseology, transition call-outs, or lost-communication procedures; those procedures are established in AIM Chapter 4 (Air Traffic Control).

This chapter does not include a dedicated Class B airspace paragraph. Class B airspace dimensions, pilot-certification, and equipment requirements are established in AIM 3-2-3, which was not among the sub-chapters aggregated into this chapter file. Class B airspace is nonetheless referenced throughout this chapter wherever it forms part of a general rule spanning multiple classes.

3.1 Overlapping Airspace Designations

This paragraph establishes which set of operating rules applies when two or more airspace designations apply to the same volume of airspace.

a. When two or more airspace designations apply to the same volume of airspace, the operating rules of the more restrictive designation will apply throughout the overlap. This rule binds every pilot and every ATC facility operating in the overlap, regardless of position. Each airspace designation corresponds to one of six classes, Class A through Class G, ranked in Table 1 from most restrictive to least restrictive.

Table 1. Airspace Class Restrictiveness Ranking (Most to Least Restrictive)

Rank	Class	More restrictive than
1	Class A	Class B, Class C, Class D, Class E, Class G
2	Class B	Class C, Class D, Class E, Class G
3	Class C	Class D, Class E, Class G
4	Class D	Class E, Class G
5	Class E	Class G
6	Class G	(none; least restrictive)

Legend: Class A through Class G = the six airspace classes. Class A is established in paragraph 3.5, Class B in AIM 3-2-3, Class C in paragraph 3.6, Class D in paragraph 3.7, Class E in paragraph 3.8, and Class G in paragraph 3.9 of this chapter.

Example: Class D Surface Area Beneath a Class B Shelf Situation: An airport's Class D surface area lies directly beneath a Class B shelf that begins at 4,000 ft mean sea level (MSL), so the two designations overlap between the surface and 4,000 ft MSL. Application: Because Class B ranks above Class D in Table 1, each pilot operating within that overlap complies with the Class B operating rules for that block of airspace rather than the Class D operating rules, even though the Class D surface area remains in effect for the portion of airspace outside the overlap.

Note: The ranking in Table 1 governs only which operating rules apply within an overlap. It does not change the lateral or vertical limits of any class, which remain as established in paragraphs 3.5, 3.6, 3.7, 3.8, and 3.9 of this chapter, or in AIM 3-2-3 for Class B airspace.

3.2 Basic VFR Weather Minimums

This paragraph establishes the flight visibility and cloud clearance each pilot must maintain when operating an aircraft under basic VFR, by airspace class, and states when a ceiling at a controlled-airspace airport prohibits VFR operation beneath it. This paragraph is the authoritative statement of VFR weather minimums for this chapter; paragraph 3.9.b (Class G Airspace, VFR Requirements) applies this paragraph's Table 2 to Class G airspace rather than restating it.

a. When operating an aircraft under basic VFR, the pilot must not fly at a flight visibility, or at a distance from clouds, less than the value stated in Table 2 for the aircraft's current altitude and class of airspace.

Note: A student pilot is subject to additional weather-minimum restrictions established in Title 14 of the Code of Federal Regulations (14 CFR) 61.89(a)(6) and (7), not reproduced in this chapter.

Table 2. Basic VFR Weather Minimums by Airspace Class

Airspace	Flight Visibility	Distance from Clouds
Class A	Not applicable	Not applicable
Class B	3 SM	Clear of clouds
Class C	3 SM	500 ft below, 1,000 ft above, 2,000 ft horizontal
Class D	3 SM	500 ft below, 1,000 ft above, 2,000 ft horizontal
Class E, below 10,000 ft MSL	3 SM	500 ft below, 1,000 ft above, 2,000 ft horizontal
Class E, at or above 10,000 ft MSL	5 SM	1,000 ft below, 1,000 ft above, 1 SM horizontal
Class G, 1,200 ft or less AGL, day	1 SM	Clear of clouds
Class G, 1,200 ft or less AGL, night	3 SM	500 ft below, 1,000 ft above, 2,000 ft horizontal
Class G, more than 1,200 ft AGL and below 10,000 ft MSL, day	1 SM	500 ft below, 1,000 ft above, 2,000 ft horizontal
Class G, more than 1,200 ft AGL and below 10,000 ft MSL, night	3 SM	500 ft below, 1,000 ft above, 2,000 ft horizontal
Class G, at or above 10,000 ft MSL	5 SM	1,000 ft below, 1,000 ft above, 1 SM horizontal
Class G, helicopter, 1,200 ft or less AGL, day	1/2 SM	Clear of clouds
Class G, helicopter, 1,200 ft or less AGL, night	1 SM	Clear of clouds

Legend: AGL = above ground level (used from first occurrence in this table onward). MSL = mean sea level. SM = statute miles.

Note: Class A airspace requires operation under IFR; no VFR visibility or cloud-clearance minimum applies there.

b. When the ceiling at an airport within controlled airspace designated to the surface is less than 1,000 ft AGL, the pilot must not operate the aircraft beneath that ceiling under VFR, unless the pilot holds a Special VFR clearance issued under 14 CFR 91.157.

Example: Special VFR Clearance Request

PILOT: "Springfield Tower, Cessna Three Four Two Papa Sierra, ten miles east, request Special VFR into the Class Delta, reported ceiling eight hundred broken."

TOWER: "Cessna Three Four Two Papa Sierra, Springfield Tower, Special VFR clearance to enter the Class Delta surface area, maintain special VFR conditions, altimeter two niner niner two."

Note: This paragraph does not establish Special VFR clearance procedures; those procedures are established in 14 CFR 91.157.

3.3 VFR Cruising Altitudes and Flight Levels

This paragraph establishes the cruising altitude each pilot must select when operating under VFR more than 3,000 ft AGL and not assigned an altitude by ATC.

a. When operating under VFR more than 3,000 ft AGL and not assigned a specific altitude by ATC, the pilot must select a cruising altitude appropriate to the magnetic course flown, per Table 3.

b. On a magnetic course of 000 through 179 degrees, the pilot must maintain an odd-thousand-foot MSL altitude plus 500 ft when operating below 18,000 ft MSL, or an odd flight level (FL) plus 500 ft when operating above 18,000 ft MSL up to FL290.

c. On a magnetic course of 180 through 359 degrees, the pilot must maintain an even-thousand-foot MSL altitude plus 500 ft when operating below 18,000 ft MSL, or an even FL plus 500 ft when operating above 18,000 ft MSL up to FL290.

Table 3. VFR Cruising Altitudes and Flight Levels

Magnetic Course	Altitude Range	Required Cruising Altitude
000-179 degrees	More than 3,000 ft AGL, below 18,000 ft MSL	Odd thousands MSL plus 500 ft (3,500 ft MSL; 5,500 ft MSL; 7,500 ft MSL)
000-179 degrees	Above 18,000 ft MSL to FL290	Odd FL plus 500 ft (FL195; FL215; FL235)
180-359 degrees	More than 3,000 ft AGL, below 18,000 ft MSL	Even thousands MSL plus 500 ft (4,500 ft MSL; 6,500 ft MSL; 8,500 ft MSL)
180-359 degrees	Above 18,000 ft MSL to FL290	Even FL plus 500 ft (FL185; FL205; FL225)

Legend: AGL = above ground level. MSL = mean sea level. FL = flight level.

Example: VFR Cruising Altitude Report

Pilot to Flight Service Station (FSS), when filing a VFR flight plan for a course of 180-359 degrees:

Pilot: "Leesburg Radio, Cessna Three Four Alpha Bravo, VFR flight plan, cruising altitude four thousand five hundred."

FSS: "Cessna Three Four Alpha Bravo, Leesburg Radio, four thousand five hundred received."

Note: This paragraph applies only while the pilot holds no ATC-assigned altitude; once ATC assigns an altitude, that assignment governs in place of the magnetic-course rule in b. and c. for its duration.

3.4 Controlled Airspace

This paragraph establishes the general rules for controlled airspace (Class A, Class B, Class C, Class D, and Class E airspace), within which ATC provides service to IFR and VFR flights according to the airspace class. Paragraph 3.5 through paragraph 3.9 establish additional rules specific to Class A, Class C, Class D, Class E, and Class G airspace; Class B airspace requirements are established in AIM 3-2-3.

a. Controlled airspace is the generic term for Class A, Class B, Class C, Class D, and Class E airspace.

Table 4. Controlled-Airspace Entry and Authorization Requirements by Class

Class	IFR Flight Plan and Clearance (b)	VFR Clearance/Radio Before Entry (d)	Ultralight Prior Authorization (g)	Balloon Prior Authorization Below 2,000 ft (h)	Parachute Jump Prior Authorization (i)
A	X	—	X	—	X
B	X	X	X	X	X
C	X	X	X	X	X
D	X	X	X	X	X
E	X	—	X¹	X	—

Legend: X = requirement stated in this paragraph for that class. — = not stated in this paragraph for that class. IFR = instrument flight rules. VFR = visual flight rules. ft = feet. ¹For an ultralight vehicle, the Class E entry requirement in g. applies only within the lateral boundaries of the surface area of Class E airspace designated for an airport.

b. Before conducting IFR operations in any class of controlled airspace, the pilot must file an IFR flight plan. The pilot must also obtain the appropriate ATC clearance before entering the airspace.

Example: IFR Clearance Delivery Sender: The pilot. Condition: The pilot has filed an IFR flight plan and is ready to depart into controlled airspace. Call:

Pilot: "Clearance Delivery, Viper 21, IFR to Nellis, ready to copy."
Clearance Delivery: "Viper 21, cleared to Nellis as filed, climb and maintain five thousand, expect flight level two-five-zero one-zero minutes after departure, departure frequency one-two-five point four, squawk zero-three-one-two."

Response: The pilot reads the clearance back to Clearance Delivery before departure.

c. For each aircraft operating under IFR in controlled airspace, the controlling facility (Tower, Approach, Departure, or Center (Air Route Traffic Control Center (ARTCC)), as applicable) will provide standard IFR separation from other IFR traffic.

d. Two-Way Radio Communication and Clearance for Entry.

(1) Before entering Class B, Class C, or Class D airspace, the pilot must ensure that the ATC clearance or two-way radio communication requirement established for that class is met.

Note: Receiving ATC radar advisories does not relieve the pilot of this responsibility.

(2) When the ATC facility responds to the pilot's initial call using the aircraft's call sign, two-way radio communication is established and the pilot may enter the airspace named in (1), subject to any instruction the ATC facility gives. When the ATC facility responds without using the aircraft's call sign, two-way radio communication is not established and the pilot must not enter that airspace.

(3) When the ATC facility instructs the pilot to remain outside the airspace named in (1) because of traffic or workload, the pilot must remain outside that airspace until the ATC facility authorizes entry.

Example: Establishing Two-Way Radio Communication Sender: The pilot. Condition: The pilot intends to enter Class D airspace under VFR. This example illustrates the call sign test in (2); the same test governs entry into Class B and Class C airspace. Call:

Pilot: "Springfield Tower, Cessna 5 Alpha Bravo, ten miles west at two thousand five hundred, inbound for landing, with information Bravo."
Tower: "Cessna 5 Alpha Bravo, Springfield Tower, enter left downwind for runway 18, report entering the pattern."

Response: The Tower's reply using the aircraft's call sign establishes two-way radio communication under (2). See paragraph 3.6.c for the Class C-specific initial-call content and paragraph 3.7.d for the Class D-specific initial-call content, each illustrated with its own example there.

e. Workload permitting, the controlling facility will provide traffic advisories to aircraft in controlled airspace.

Note: This is a workload-permitting service (discretion).

f. When, in the controlling facility's judgment, an aircraft's altitude places it in unsafe proximity to terrain or obstructions, the controlling facility must issue a safety alert to the pilot. When the controlling facility observes another aircraft placing the aircraft in unsafe proximity, the controlling facility must issue a safety alert to the pilot and should offer an alternative course of action when feasible (discretion).

Example: Terrain/Obstruction Safety Alert Sender: The controlling facility (Approach, in this example). Condition: The controller judges the aircraft's altitude to be in unsafe proximity to terrain or obstructions. Call:

Approach: "Viper 34, LOW ALTITUDE ALERT, CHECK YOUR ALTITUDE IMMEDIATELY."

Response: The pilot acknowledges the alert and takes corrective action.

Example: Aircraft Conflict Safety Alert Sender: The controlling facility (Center, in this example). Condition: The controller observes another aircraft creating unsafe proximity to the aircraft under the controller's control. Call:

Center: "Cactus 12, TRAFFIC ALERT, traffic twelve o'clock, two miles, opposite direction, altitude indicates same, suggest climb immediately."

Response: The pilot acknowledges the alert and may comply with the suggested course of action.

g. Within Class A, Class B, Class C, or Class D airspace, or within the lateral boundaries of the surface area of Class E airspace designated for an airport, the pilot of an ultralight vehicle must not operate without prior authorization from the ATC facility having jurisdiction over that airspace (14 CFR Part 103).

h. Below 2,000 ft [VERIFY: AGL or MSL reference frame not stated in the fetched source text] in Class B, Class C, Class D, or Class E airspace, the operator of an unmanned free balloon must not operate without prior authorization from the ATC facility having jurisdiction over that airspace (14 CFR Part 101).

i. Into or within Class A, Class B, Class C, or Class D airspace, a person must not make a parachute jump without prior authorization from the ATC facility having jurisdiction over that airspace (14 CFR Part 105).

Example: Prior ATC Authorization for a Restricted Activity Sender: The operator (ultralight pilot, balloon operator, or jump operator, as applicable). Condition: The operator intends to conduct an activity restricted under g., h., or i. within or into the affected airspace. Call:

Operator: "Springfield Tower, jump aircraft one two three, requesting authorization for a parachute jump over the drop zone, time one-four-zero-zero."
Tower: "Jump aircraft one two three, Springfield Tower, authorized, jump run approved not below three thousand five hundred, traffic will be advised."

Response: The operator must not commence the restricted activity until the ATC facility having jurisdiction issues authorization.

3.5 Class A Airspace

This paragraph establishes the vertical and lateral extent of Class A airspace and the operating requirements for each pilot and for Center within it.

a. Class A airspace extends from 18,000 ft MSL up to and including flight level 600 (FL600), and includes the airspace overlying the waters within 12 nautical miles (NM) of the coast of the 48 contiguous states and Alaska. Class A airspace also includes designated international airspace beyond 12 NM off those coasts, within areas of domestic radio navigation signal or ATC radar coverage, where domestic ATC procedures apply.

b. Within Class A airspace, each pilot must operate the aircraft under IFR unless Center authorizes otherwise for that flight. The pilot obtains the IFR flight plan and clearance required by paragraph 3.4.b before entering Class A airspace.

Example: Climb Into Class A Airspace

Pilot: "Center, [callsign], request higher, flight level three five zero."

Center: "[Callsign], Center, climb and maintain flight level three five zero."

c. Within Class A airspace, each aircraft must be equipped with the transponder and Automatic Dependent Surveillance-Broadcast (ADS-B) Out equipment required for operation in that airspace.

d. Class A airspace is not charted as a bounded area on aeronautical charts; it is defined by altitude alone and applies uniformly across its lateral extent.

Note: This paragraph does not establish clearance-request timing, transition call-outs, or lost-communication procedures for Class A airspace; those procedures are established in AIM Chapter 4 (Air Traffic Control).

3.6 Class C Airspace

This paragraph establishes the dimensions, equipment, two-way radio communication, and air traffic service requirements for Class C airspace and its outer area.

a. Dimensions

(1) Class C airspace generally extends from the surface to 4,000 ft above the primary airport's elevation, charted in MSL, and consists of a core surface area and a surrounding shelf area.

Table 5. Class C Airspace Dimensions

Layer	Radius	Floor	Ceiling
Core surface area	5 NM	Surface	4,000 ft above airport elevation
Shelf area	10 NM	1,200 ft above airport elevation	4,000 ft above airport elevation

Legend: NM = nautical miles. Ceiling values are charted in MSL.

Note: Each Class C airspace area is individually tailored to its airport; Table 5 states the typical structure only.

b. Equipment

(1) No additional pilot certification is required to operate in Class C airspace.

(2) Each pilot must carry an operable two-way radio to operate in Class C airspace.

(3) Unless the pilot obtains prior authorization from ATC to operate without it, each pilot's aircraft must be equipped with an operable radar beacon transponder with automatic altitude reporting and operable ADS-B Out equipment.

c. Two-Way Radio Communication

(1) Before entering Class C airspace, the pilot must establish two-way radio communication with the ATC facility providing Class C service.

(2) While within Class C airspace, the pilot must maintain that two-way radio communication.

(3) At the pilot's discretion, while still far enough from the Class C boundary to complete the initial call before reaching it, the pilot will call the ATC facility on the published frequency and state the aircraft's position, altitude, radar beacon code, destination, and a request for Class C service.

Note: Paragraph 3.4.d(2) states how two-way radio communication is established (call sign acknowledged versus omitted), and paragraph 3.4.d(3) states the remain-outside instruction; both apply to Class C airspace under this paragraph.

Example: Class C Airspace Entry Contact

Pilot (clear of the boundary, initial call): "Dulles Approach, Cessna Three Four Bravo, one five miles west, three thousand five hundred, request Class Charlie service to Dulles."

Controller (communication established): "Cessna Three Four Bravo, Dulles Approach, standby." Result: Two-way radio communication is established under paragraph 3.4.d(2); the pilot may enter Class C airspace when instructed.

Controller (communication not established): "Aircraft calling Dulles Approach, standby." Result: Two-way radio communication is not established under paragraph 3.4.d(2); the pilot must not enter Class C airspace and must remain clear until the controller uses the aircraft's call sign.

Controller (workload): "Cessna Three Four Bravo, Dulles Approach, remain outside the Class Charlie airspace and standby." Result: Communication is established, but the pilot must remain outside Class C airspace under paragraph 3.4.d(3) until the controller authorizes entry.

d. Air Traffic Services

(1) After the pilot establishes two-way radio communication and the controller establishes radar contact, the ATC facility will sequence the aircraft to the primary airport and provide Class C service within Class C airspace and the outer area.

(2) Beyond the outer area, the ATC facility will provide basic radar service on a workload-permitting basis.

(3) When workload requires it, the controller may terminate the service in (2).

(4) Within the outer area, the pilot may decline the associated services and may request to discontinue them at any time.

e. Separation

(1) Within Class C airspace and the outer area, once two-way radio communication and radar contact are established, the controller will separate VFR aircraft from IFR aircraft using visual separation, 500 ft vertical separation, target resolution, or wake turbulence procedures.

(2) When an aircraft is behind and less than 1,000 ft below a super or heavy aircraft, or when a small aircraft follows a large aircraft on final approach, the controller will apply wake turbulence procedures.

Note: The controller suspends the separation services in (1) during a radar outage.

3.7 Class D Airspace

This paragraph establishes the dimensions, tower operating-hours rules, equipment requirement, and two-way radio contact procedures for Class D airspace.

a. Definition. Class D airspace extends upward from the surface to 2,500 ft above the primary airport's elevation, charted in MSL, surrounding an airport with an operating control tower. Each Class D airspace area is tailored individually, and its lateral dimensions are normally sized to contain any published instrument approach procedure for that airport.

b. Tower Operating Hours. A Class D surface area may be designated full-time, meaning the Tower operates 24 hours a day, or part-time, with the effective hours published in the Chart Supplement.

(1) When a part-time Class D surface area is not in effect, it reverts to either Class E surface-area rules or Class G airspace, whichever is published in the Chart Supplement for that airport.

(2) When a part-time Class D surface area reverts to Class G airspace, the Class G airspace extends up to, but not including, the overlying controlled airspace, normally the Class E transition area beginning at 700 ft AGL or 1,200 ft AGL.

Note: The Chart Supplement entry for the airport states the applicable part-time status, for example "other times CLASS E" or "other times CLASS G."

c. Equipment. Unless otherwise authorized by ATC, each pilot operating within Class D airspace must have an operable two-way radio.

d. Two-Way Radio Contact, Arrival or Through Flight.

(1) Before entering Class D airspace, the pilot must establish two-way radio communication with the Tower.

(2) While operating within Class D airspace, the pilot must maintain that two-way radio communication.

(3) When approaching the Class D airspace boundary, the pilot should initiate the radio call far enough out to preclude entering the airspace before two-way communication is established.

(4) On initial contact with the Tower, the pilot should state the aircraft's position, altitude, destination, and any request.

Note: Paragraph 3.4.d(2) states how two-way radio communication is established (call sign acknowledged versus omitted), illustrated for Class D airspace in the examples below.

Example: Radio Contact Established (Call Sign Acknowledged) Pilot (approaching the Class D boundary): "Manassas Tower, Cessna Three Four Bravo, one four miles west at three thousand five hundred, landing, with information Alpha." Tower: "Cessna Three Four Bravo, Manassas Tower, standby." Note: Because the Tower's reply includes the aircraft's call sign, two-way radio communication is established under paragraph 3.4.d(2), and the pilot may enter Class D airspace, even though the Tower has not yet issued a clearance or instruction.

Example: Radio Contact Not Established (Call Sign Omitted) Pilot (approaching the Class D boundary): "Manassas Tower, Cessna Three Four Bravo, one four miles west at three thousand five hundred, landing, with information Alpha." Tower: "Aircraft calling Manassas Tower, standby." Rule: When the Tower's reply omits the aircraft's call sign, two-way radio communication is not established under paragraph 3.4.d(2), and the pilot must not enter Class D airspace.

e. Remain-Outside Instruction. When workload or traffic conditions prevent immediate entry, the Tower will instruct the pilot to remain outside Class D airspace, under paragraph 3.4.d(3), until conditions permit entry.

Example: Remain Outside and Standby Tower: "Cessna Three Four Bravo, remain outside the Class Delta airspace and standby." Pilot: "Cessna Three Four Bravo, WILCO."

f. Non-Operating Tower Hours. During hours when a part-time Tower is not in operation, the pilot must comply with the Class E surface-area rules, or with the combination of Class E rules above 700 ft AGL and Class G rules from the surface to 700 ft AGL, whichever is published in the Chart Supplement for that airport.

g. Departure Radio Requirements.

(1) Before departing a primary or satellite airport with an operating Tower, the pilot must establish two-way radio communication with the Tower.

(2) Once two-way radio communication with the Tower is established, the pilot must maintain that communication while operating within Class D airspace.

(3) While operating within Class D airspace after departure, the pilot must comply with ATC instructions.

(4) When departing a satellite airport without an operating Tower, the pilot must establish two-way radio communication with the ATC facility having jurisdiction over the Class D airspace as soon as practicable after departing.

h. Speed Restriction. Unless otherwise authorized or required by ATC, no pilot may operate an aircraft at or below 2,500 ft above the surface within 4 NM of the primary airport of a Class D airspace area at a speed greater than 200 knots indicated airspeed (KIAS) (approximately 230 mph).

i. Surface Area Arrival Extensions.

(1) Where every arrival extension to a Class D surface area is 2 NM or less, each extension remains part of the Class D surface area.

(2) Where any single arrival extension exceeds 2 NM, all arrival extensions for that airport become Class E airspace instead.

(3) Outside the published hours of the underlying Class D surface area, each arrival extension carries the same status, Class E or Class G, that the surface area itself reverts to under b.

j. Separation for VFR Aircraft. ATC does not provide separation services to VFR aircraft within Class D airspace.

Note: Class D airspace is depicted on Sectional and Terminal Area Charts with blue segmented lines, and on IFR En Route Low Altitude Charts with a boxed "D." The pilot should use this depiction to identify the Class D boundary before initiating contact with the Tower.

3.8 Class E Airspace

This paragraph establishes the equipment requirements, entry procedures, and separation limits for Class E airspace, the classification applied to most terminal transition areas, federal airways, and en route airspace not otherwise designated Class A, Class B, Class C, or Class D.

a. Where airspace requires control for terminal or en route purposes and is not designated Class A, Class B, Class C, or Class D, the Federal Aviation Administration (FAA) designates it Class E airspace.

b. At or above 10,000 ft MSL within the 48 contiguous states and the District of Columbia, excluding airspace at or below 2,500 ft AGL, unless ATC authorizes otherwise for that flight, each pilot must operate with an operable radar beacon transponder with automatic altitude-reporting capability and operable ADS-B Out equipment.

c. Over the Gulf of America from the United States coastline out to 12 NM, at or above 3,000 ft MSL, unless ATC authorizes otherwise for that flight, each pilot must operate with operable ADS-B Out equipment.

Note: ADS-B Out is required in the Gulf of America segment in c. even though a transponder is not separately required there.

Example: Requesting Authorization for Inoperative Equipment Condition: The pilot's transponder or ADS-B Out equipment is inoperative before entering the airspace in b. or c. The pilot calls the controlling Center (ARTCC) or Approach Control facility.

PILOT: "Denver Center, November One Two Three Alpha Bravo, transponder inoperative, request authorization to operate in Class Echo airspace, one seven thousand."

DENVER CENTER: "November One Two Three Alpha Bravo, Denver Center, authorized to operate transponder inoperative, maintain one seven thousand."

Note: If ATC does not authorize the deviation, the pilot must not enter the affected airspace with the required equipment inoperative.

d. At an airport where the control tower is not in operation, and where the airport has weather observation and reporting capability and communication capability with aircraft down to the runway surface, the FAA designates a Class E surface area extending upward from the surface to a designated altitude or to the adjacent or overlying controlled airspace.

e. When the control tower at a Class C or Class D airport closes for the day, that airport's surface area reverts to Class E airspace for the duration of the closure.

f. Before operating at an airport with part-time surface-area status, the pilot will check the Chart Supplement airport page for current surface-area status.

g. Except where the equipment requirements in b. or c. apply, the pilot may enter Class E airspace without first establishing two-way radio contact or receiving an ATC clearance.

Note: This differs from Class D airspace (paragraph 3.7.d), where the pilot must establish two-way radio contact with the Tower before entering. Class E airspace carries no equivalent contact-and-clearance requirement, except as required by b. or c. above.

h. Within Class E airspace, ATC does not provide separation services to VFR aircraft.

i. Except where a lower floor is designated, Class E airspace begins at the surface, 700 ft AGL, 1,200 ft AGL, or 14,500 ft MSL, depending on location, and extends upward to, but not including, 18,000 ft MSL.

j. Above FL600, the airspace is Class E airspace.

3.9 Class G Airspace

This paragraph establishes the definition of Class G airspace, the VFR weather-minimum requirement that applies within it, and the IFR obstacle-clearance and cruising-altitude rules that apply within it.

a. General

(1) Class G airspace is uncontrolled airspace: any portion of the NAS not designated Class A, Class B, Class C, Class D, or Class E airspace.

Note: Because Class G airspace is uncontrolled, no facility, whether Clearance Delivery, Ground, Tower, Departure, Approach, or Center, holds designated air traffic control authority over an aircraft solely because that aircraft is operating within Class G airspace.

Example: Applying the Definition Condition: A given volume of the NAS carries no charted designation as Class A, Class B, Class C, Class D, or Class E airspace. Result: That volume is Class G airspace by this definition, regardless of its altitude or location, and regardless of whether any facility name appears on the chart for the surrounding area.

Note: Paragraph 3.9.b establishes the VFR weather-minimum requirement for Class G airspace, and paragraph 3.9.c establishes the IFR obstacle-clearance and cruising-altitude requirements for Class G airspace.

b. VFR Requirements

(1) During VFR flight in Class G airspace, the pilot must maintain the minimum flight visibility and distance from clouds established in paragraph 3.2.a and Table 2.

Note: [VERIFY: table values not retrievable from this section's source text; confirm against 14 CFR 91.155 before publishing final minimums to aircrew.]

c. IFR Requirements

(1) When operating under IFR, the pilot must, in addition to complying with the cruising altitude required under (2), maintain at least 1,000 ft above the highest obstacle within a horizontal distance of 4 NM of the course to be flown, or at least 2,000 ft above the highest obstacle within that distance in designated mountainous terrain, as established in 14 CFR 91.177.

(2) When operating under IFR in Class G airspace below 18,000 ft MSL, the pilot must select a cruising altitude from Table 6 according to the magnetic course flown.

Table 6. IFR Cruising Altitudes, Class G Airspace, Below 18,000 ft MSL

Magnetic Course	Required Altitude
000° through 179°	Odd thousands MSL (3,000 ft; 5,000 ft; 7,000 ft; etc.)
180° through 359°	Even thousands MSL (2,000 ft; 4,000 ft; 6,000 ft; etc.)

Legend: MSL = mean sea level.

Note: Table 6 states IFR cruising altitudes without the 500 ft addition that paragraph 3.3 (VFR Cruising Altitudes and Flight Levels) requires for VFR flight; the two rules are not interchangeable.

Example: IFR Position Report, Class G Airspace

Pilot (to the FSS, on reaching a reporting point while flying a magnetic course of 100 degrees, selecting altitude from Table 6): "Kodiak Radio, November One Two Three Alpha Bravo, Big Lake, one four five six Zulu, level five thousand, estimating Talkeetna one five one zero Zulu."

The FSS acknowledges receipt of the position report, including the reported altitude.

3.10 Prohibited Areas

This paragraph establishes the prohibition on flight within prohibited areas and the corresponding restriction on Center, Approach, or Departure authorizing entry into them.

a. Within the lateral and vertical limits of a charted prohibited area, the pilot must not operate the aircraft.

Note: This prohibition admits no operational exception.

b. When an aircraft's filed or amended route would enter a charted prohibited area, Center, Approach, or Departure must not issue a clearance, vector, instruction, or coordinated authorization that routes the aircraft within its boundaries.

Example: Prohibited Area Avoidance

Condition: The pilot identifies a charted prohibited area along the aircraft's present course and requests routing to remain clear.

PILOT: "Center, Falcon One Two, we show Prohibited Area P-40 ahead on our present course, request vectors to remain clear."

CENTER: "Falcon One Two, turn left heading two seven zero, vectors to remain clear of Prohibited Area P-40, advise reaching clear of the area."

PILOT: "Left heading two seven zero, Falcon One Two."

c. When a flight is planned through or near published special use airspace, the pilot should verify the location of charted prohibited areas using current aeronautical charts before departure.

3.11 Restricted Areas

This paragraph establishes how the ATC facility handles IFR traffic on a route within joint-use restricted airspace, and how restricted areas are depicted for flight planning.

a. General. A restricted area is airspace within which flight is not wholly prohibited but is subject to restriction because of hazardous activity conducted within it, such as artillery firing, aerial gunnery, or guided missiles.

Note: Entering an active restricted area without authorization from the using or controlling agency may expose the aircraft to the hazardous activity the area was established to contain.

b. Joint-Use Restricted Airspace.

(1) When an aircraft is operating on an IFR clearance, including a clearance to maintain VFR-on-top, on a route within joint-use restricted airspace that is inactive and has been released to the FAA, the ATC facility will allow the aircraft to operate in that airspace without issuing a specific clearance for it.

(2) When the joint-use restricted airspace is active and has not been released to the FAA, the ATC facility will issue a clearance that ensures the aircraft avoids the restricted airspace, unless the aircraft is on an approved altitude reservation mission or the pilot has obtained separate permission to operate in the airspace and informs the ATC facility.

Example: Pilot-Obtained Permission Through Active Restricted Airspace Condition: The pilot has coordinated separate permission with the using agency to transit an active restricted area not released to the FAA, and informs the ATC facility of that permission before entry.

Pilot: "Center, [callsign], request direct through Restricted Area 1234, coordinated with range control for entry at this time." Center: "[Callsign], cleared as requested through Restricted Area 1234, report exiting the area."

Note: This procedure applies only to joint-use restricted airspace, not to prohibited areas or to restricted areas that are not joint-use.

c. Charting. Permanent restricted areas are depicted on Sectional Aeronautical charts, VFR Terminal Area charts, and the appropriate En Route charts. Temporary restricted areas are not charted.

3.12 Military Operations Areas

This paragraph establishes radio-communication and traffic-advisory procedures for MOAs: airspace with published vertical and lateral limits established to separate military training activity, including air combat maneuvers, air intercepts, aerobatics, formation training, and low-altitude tactics, from IFR traffic.

a. When a MOA is active, Center will clear nonparticipating IFR traffic through the MOA if Center can maintain IFR separation from the military activity. When Center cannot maintain that separation, Center will reroute or restrict nonparticipating IFR traffic around the MOA.

Example: IFR Transit of an Active MOA

(1) Center clears the flight through. Pilot: "Center, Speedbird Three-Four, request direct Ranger Fix through the Falcon MOA." Center: "Speedbird Three-Four, cleared direct Ranger Fix through Falcon MOA, maintain flight level two-two-zero, military traffic working below your altitude."

(2) Center cannot maintain separation and reroutes. Pilot: "Center, Speedbird Three-Four, request direct Ranger Fix through the Falcon MOA." Center: "Speedbird Three-Four, unable direct, Falcon MOA active with intercept training through your requested altitude, fly heading two-seven-zero, vectors around the MOA."

b. Within an active MOA, a military pilot may conduct aerobatic maneuvers that are otherwise restricted in controlled airspace, and may operate at indicated airspeeds greater than 250 KIAS below 10,000 ft MSL.

Note: These authorizations apply only inside the MOA's published lateral and vertical limits. A nonparticipating pilot should expect no such maneuvering or speed outside those limits, but should expect both inside an active MOA.

c. When planning a flight that may cross a MOA, the pilot should contact an FSS within 100 NM of the MOA to obtain the area's current activity status, altitudes, and hours of operation.

Note: A charted or scheduled MOA time does not substitute for the query in this paragraph; MOA activity status changes more frequently than charts or schedules reflect.

Example: FSS Query for MOA Status

Pilot: "Kansas City Radio, Cessna Six-Four-Alpha, request current status of the Falcon MOA." FSS: "Six-Four-Alpha, Falcon MOA active, surface through flight level two-four-zero, through zero-two-zero-zero Zulu."

d. Before entering an active MOA, the pilot should contact the controlling agency for traffic advisories.

Example: Advisories Before Entering an Active MOA

Pilot: "Falcon Approach, Cessna Six-Four-Alpha, eight miles west of Falcon MOA, VFR, request traffic advisories through the area." Controlling Agency: "Six-Four-Alpha, radar contact, Falcon MOA active with fighter intercept training surface through one-eight thousand, no factor traffic observed at this time."

e. Permanent MOAs are depicted on Sectional Aeronautical, VFR Terminal Area, and Enroute Low Altitude charts.

Note: A temporary MOA is not charted; its existence and current status are obtainable only by contacting an FSS under c. or the controlling agency under d.

3.13 Military Training Routes

This paragraph establishes the rules of operation on MTRs, the low-altitude, high-speed training corridors developed jointly by the FAA and the Department of Defense (DoD), and states how the pilot obtains current MTR information from the FSS.

a. Route Categories.

(1) On an IFR Military Training Route (IR), each pilot will comply with IFR regardless of weather conditions.

(2) On a VFR Military Training Route (VR), each pilot will comply with VFR. Flight visibility must be 5 SM or more. The pilot must not operate below a ceiling of less than 3,000 ft AGL.

Note: An MTR is generally established below 10,000 ft MSL for operations exceeding 250 knots. A route segment above 1,500 ft AGL is developed to be flown under IFR to the maximum extent possible; a segment at 1,500 ft AGL or below is generally developed to be flown under VFR. A route may still carry segments outside these bands where needed for route continuity, such as climbout, descent, or mountainous terrain.

b. Route Identification. A route with no segment above 1,500 ft AGL carries a four-numeral designator (e.g., IR1206, VR1207). A route with at least one segment above 1,500 ft AGL carries a three-numeral designator (e.g., IR206, VR207).

c. Special Military Activity Route (SMAR). A SMAR designates airspace associated with an IR route within which the DoD conducts periodic Unmanned Aircraft System (UAS) operations. A crewed aircraft may accompany the UAS to give the UAS pilot visual observation of other air traffic in the vicinity.

d. Preflight MTR Briefing. The pilot may obtain current MTR information from the FSS during preflight planning.

e. Inflight MTR Advisory. When operating within 100 NM of a particular MTR, the pilot should contact the FSS to obtain current route usage, including scheduled activity times, altitudes in use on each route segment, and actual route width. The pilot should state the MTR designation, present position, route of flight, and destination in the initial call.

Note: Route width varies by MTR and may extend several miles on either side of the charted centerline; stating the designation, position, route, and destination in the initial call lets the FSS specialist identify the applicable MTR or SMAR without added frequency congestion.

Example: MTR Advisory Request

Pilot: "Kansas City Radio, Cessna Three Four Bravo, request MTR advisory, IR178, position two five miles west of Salina, route of flight direct Wichita, landing Wichita."

FSS: "Cessna Three Four Bravo, Kansas City Radio, IR178 active one two zero zero to one six zero zero Zulu, surface to five thousand, route width ten miles each side of centerline."

f. Nonparticipating Traffic. A pilot not participating in scheduled MTR activity may operate within an MTR or SMAR. Each pilot should exercise extreme vigilance when operating through or near an MTR or SMAR because of the high-speed, low-altitude activity the route may contain.

References

AIM 3-1-3 — Hierarchy of Overlapping Airspace Designations
AIM 3-1-4 — Basic VFR Weather Minimums
AIM 3-1-5 — VFR Cruising Altitudes and Flight Levels
AIM 3-2-1 — General (Controlled Airspace)
AIM 3-2-2 — Class A Airspace
AIM 3-2-4 — Class C Airspace
AIM 3-2-5 — Class D Airspace
AIM 3-2-6 — Class E Airspace
AIM 3-3-1 — General (Class G Airspace)
AIM 3-3-2 — VFR Requirements (Class G Airspace)
AIM 3-3-3 — IFR Requirements (Class G Airspace)
AIM 3-4-2 — Prohibited Areas
AIM 3-4-3 — Restricted Areas
AIM 3-4-5 — Military Operations Areas
AIM 3-5-2 — Military Training Routes

Chapter 4 — Air Traffic Control Services and Procedures

Purpose

This chapter establishes the Air Traffic Control (ATC) services provided to civil, military, and formation aircraft; the radio communications phraseology and techniques used between each pilot and each facility; the procedures governing airport surface and traffic-pattern operations; and the clearance, adherence, and separation standards that govern instrument flight rules (IFR) and visual flight rules (VFR) flight in controlled airspace. It applies to every phase of flight from initial ATC contact through taxi-in after landing, at every class of controlled and uncontrolled airport.

Scope

This chapter is organized into four groupings, numbered continuously:

Paragraphs 4.1–4.9, Air Traffic Control: the facilities (Center, Tower, Approach, an FSS) and the services each provides.
Paragraphs 4.10–4.19, Radio Communications Phraseology and Techniques: how a pilot and a controller speak to each other on frequency.
Paragraphs 4.20–4.28, Airport Operations: traffic patterns, taxi, and runway procedures at towered and non-towered airports.
Paragraphs 4.29–4.41, ATC Clearances and Aircraft Separation: what a clearance authorizes, how a pilot and a controller act on it, and how ATC separates aircraft.

This chapter does not cover airspace classification, which is established in Chapter 3, Airspace, or en route and arrival procedures such as Standard Terminal Arrivals and en route communications, which are established in Chapter 5, Air Traffic Procedures. This contract's cross-reference convention is stated once, in the Preface.

A. Air Traffic Control (Paragraphs 4.1–4.9)

4.1 Air Route Traffic Control Centers

This paragraph establishes the primary purpose of an Air Route Traffic Control Center (ARTCC), referred to in this chapter as Center, and identifies the phase of flight and category of flight plan it exists to serve.

1.a. For any aircraft operating on an instrument flight rules (IFR) flight plan within controlled airspace, during the en route phase of flight, Center will provide air traffic service to the flight.

Note: Ground, Tower, and Approach/Departure provide air traffic service during the taxi, takeoff, and terminal phases of a flight; see paragraph 4.2, Control Towers. This paragraph addresses only the en route phase served by Center.

Example: En Route Check-In with Center Pilot: "Denver Center, Reach Three One, level, flight level three three zero." Denver Center: "Reach Three One, Denver Center, ROGER."

4.2 Control Towers

This paragraph establishes the role of the airport traffic control tower, referred to in this chapter as Tower, in the flow of aircraft traffic on and near an airport, including cases where Tower holds delegated responsibility for separating IFR aircraft in the terminal area. Approach Control's separation procedures are established in paragraph 5.22, Approach Control, outside this chapter.

2.a. At an airport with an operating control tower, Tower will provide for a safe, orderly, and expeditious flow of aircraft traffic on the airport movement area and within the vicinity of the airport.

Example: Tower Sequencing for Landing Tower: "Cessna Four Alpha Bravo, number two following a Boeing Seven Three Seven on a four mile final, report traffic in sight." Pilot: "Traffic in sight, Cessna Four Alpha Bravo." Tower: "Cessna Four Alpha Bravo, cleared to land, runway two seven."

2.b. When a facility directive delegates responsibility for terminal-area IFR separation to Tower, Tower will provide separation between IFR aircraft in the terminal area. Otherwise, Approach Control provides that separation, as established in paragraph 5.22, Approach Control.

Note: Whether Tower or Approach Control holds separation responsibility for IFR aircraft in the terminal area at a given airport is set by local facility directive or letter of agreement (LOA) and is not uniform across airports. Each flight crew complies with whichever facility is briefed as holding that responsibility for the airport in use.

Example: Tower-Provided IFR Separation Tower: "November One Two Three Alpha Bravo, hold short runway zero niner, IFR release not available, traffic a Learjet three mile final." Pilot: "Holding short, November One Two Three Alpha Bravo." Tower: "November One Two Three Alpha Bravo, fly runway heading, climb and maintain three thousand, cleared for takeoff." Pilot: "Runway heading, climb and maintain three thousand, cleared for takeoff, November One Two Three Alpha Bravo."

4.3 Approach Control Service for VFR Arriving Aircraft

This paragraph establishes the procedure under which Approach furnishes landing information to visual flight rules (VFR) arriving aircraft before handoff to Tower, and states when a pilot may rely on the Automatic Terminal Information Service (ATIS) broadcast in place of a verbal repeat. This paragraph does not extend to IFR arrivals or to the terminal radar services described in paragraph 4.9, Terminal Radar Services for VFR Aircraft.

3.a. Where a local program for this service is in effect, Approach will furnish landing information, consisting of wind, runway in use, and altimeter setting for the airport of intended landing, to each VFR arriving aircraft upon initial contact. When the pilot states the applicable ATIS code, Approach will omit this information.

Note: See paragraph 4.5.e, HAVE NUMBERS, for the meaning and limits of that report; a pilot's use of the phrase HAVE NUMBERS does not by itself indicate receipt of the ATIS broadcast. Approach will provide traffic advisories as workload permits.

Example: Initial Contact, VFR Arrival, No ATIS Code Stated Pilot: "Approach, Cessna Three Four Alpha, level four thousand five hundred feet mean sea level (MSL)." Approach: "Cessna Three Four Alpha, wind two seven zero at one zero, runway two five, altimeter three zero one two."

Example: Initial Contact, VFR Arrival, ATIS Code Stated Pilot: "Approach, Cessna Three Four Alpha, with information Alpha." Approach: "Cessna Three Four Alpha, radar contact."

3.b. Once the predetermined point or time for the frequency change is reached, Approach will instruct the pilot to contact Tower, and the pilot will contact Tower to receive further landing information.

Example: Frequency Change to Tower Approach: "Cessna Three Four Alpha, contact Tower, one one niner point one." Pilot: "One one niner point one, Cessna Three Four Alpha."

3.c. Where this service is available, Approach will not use it to impose excessive spacing between VFR aircraft or devious routing.

3.d. When this service is offered, the pilot may decline it.

Note: Pilot participation in this service is encouraged. This service depends on ATC radar and is not available during a radar outage; see paragraph 4.9, Terminal Radar Services for VFR Aircraft, for the related terminal radar services.

4.4 Traffic Advisory Practices at Airports Without an Operating Control Tower

This paragraph establishes the Common Traffic Advisory Frequency (CTAF) monitoring ranges, Flight Service Station (FSS) advisory procedures, Universal Communications (UNICOM) station procedures, and self-announce call formats that apply when a pilot operates to, from, or in the vicinity of an airport without an operating control tower, including a towered airport whose tower is closed or operating part-time. This paragraph does not establish traffic pattern entry geometry, right-of-way, or collision-avoidance maneuvering; the visual scanning duty is established in paragraph 4.41.f, Visual Scanning for Collision Avoidance.

4.a. Pilot Alertness.

4.a.(1) When approaching or departing an airport without an operating control tower, each pilot MUST maintain visual alertness for other traffic.

4.a.(2) Under the same condition, each pilot MUST exchange traffic information with other pilots in the vicinity, using the CTAF defined in subparagraph b.

4.b. Common Traffic Advisory Frequency (CTAF).

4.b.(1) The CTAF is the frequency designated for carrying out airport advisory practices at an airport without an operating control tower.

4.b.(2) A CTAF is a UNICOM (defined in subparagraph e), MULTICOM, FSS, or control tower frequency, as published for the airport.

4.b.(3) In Alaska, a CTAF may also be established for a designated area of high-volume VFR traffic.

4.b.(4) The CTAF for a given airport is published in the Chart Supplement U.S., Chart Supplement Alaska, Alaska Terminal Publication, instrument approach procedure charts, and instrument departure procedure charts.

4.b.(5) Each pilot MAY also obtain the CTAF for a given airport from any FSS.

Note: FSS frequencies for airport advisory service are available only in Alaska.

4.c. Traffic Advisory Monitoring Range.

4.c.(1) From 10 nautical miles (NM) from the airport until landing, each pilot of inbound traffic WILL monitor and communicate on the CTAF.

4.c.(2) From engine start-up through taxi and until 10 NM from the airport, each pilot of departing traffic WILL monitor and communicate on the CTAF, unless applicable regulations or local procedures direct otherwise.

4.c.(3) While within 10 NM of the airport, operating at an altitude normally used by arriving or departing aircraft, and not conducting an arrival or a departure (for example, parachute jumping or dropping, en route transiting, or practicing maneuvers), each such pilot WILL monitor and communicate on the CTAF, unless applicable regulations or local procedures direct otherwise.

4.c.(4) In Alaska, within a designated CTAF area, the monitoring range in subparagraph (3) is the boundary of the designated area rather than 10 NM.

4.d. Airport Advisory Service by an FSS.

4.d.(1) An FSS provides two types of airport advisory service:

4.d.(1)(a) Local Airport Advisory (LAA), provided only in Alaska, at an airport with an FSS physically located on the airport that has no control tower or where the control tower operates part-time; the CTAF for an LAA airport is published in the applicable aeronautical publication.

4.d.(1)(b) Remote Airport Information Service (RAIS), provided at a nontowered airport in support of a special event, by request from the airport authority.

4.d.(2) Before transmitting outbound or inbound intentions or information to a CTAF FSS, the pilot WILL check the airport's automated weather and establish two-way communication with the FSS.

4.d.(3) Approximately 10 NM from the airport, inbound to land, the pilot WILL initiate contact with the FSS, reporting aircraft identification and type, altitude, position relative to the airport, intentions, and possession of the automated weather, and requesting airport advisory or airport information service.

Example: FSS Airport Advisory Request, Inbound Pilot: "Vero Beach Radio, Centurion Six Niner Delta Delta is ten miles south, two thousand, landing Vero Beach. I have the automated weather, request airport advisory." FSS: [states the airport advisory information listed in subparagraph (7)]

4.d.(4) Before taxiing, the pilot WILL initiate contact with the FSS, reporting aircraft identification and type, VFR or IFR, position on the airport, intentions, direction of takeoff, and possession of the automated weather, and requesting airport advisory or airport information service.

4.d.(5) Before taxiing onto the active runway for departure, the pilot WILL report intentions to the FSS.

Example: FSS Airport Advisory Request, Outbound Pilot: "Vero Beach Radio, Centurion Six Niner Delta Delta, ready to taxi to runway two two, VFR, departing to the southwest. I have the automated weather, request airport advisory." FSS: [states the airport advisory information listed in subparagraph (7)]

4.d.(6) When the pilot must change frequencies for another service after the initial report to the FSS, the pilot WILL return to the FSS frequency for a traffic update; otherwise, the pilot remains on the FSS frequency and no further action is required.

4.d.(7) Airport advisory service includes wind direction and velocity, favored or designated runway, altimeter setting, known airborne and ground traffic, Notices to Air Missions (NOTAMs), airport taxi routes, airport traffic pattern information, and instrument approach procedures, varied to fit the current traffic situation.

4.d.(8) When communicating with a CTAF FSS, the pilot SHOULD advise the FSS of the runway the pilot intends to use.

Note: Some airport managers designate specific runways for use under certain wind or other conditions; subparagraph (8) applies regardless of whether such a designation exists. Not every aircraft operating in the vicinity of the airport is necessarily in communication with the FSS.

4.e. Information Provided by UNICOM.

4.e.(1) UNICOM (Universal Communications) is a nongovernment air/ground radio communication station that may furnish airport information at a public airport that has no control tower or FSS.

4.e.(2) Upon a pilot's request, a UNICOM station MAY provide weather data, wind direction, a recommended runway, or other pertinent operational information.

4.e.(3) When the UNICOM frequency serves as the CTAF, that fact is stated in the applicable aeronautical publication.

4.f. Unavailability of FSS or UNICOM Information.

4.f.(1) When neither FSS airport advisory service nor UNICOM information is available, the pilot MAY obtain wind and weather information from a nearby controlled airport's ATIS or Automated Weather Observing System (AWOS) frequency.

4.g. Self-Announce Procedures.

4.g.(1) Self-announce is the procedure by which a pilot broadcasts position, intended flight activity, or ground operation on the designated CTAF.

Note: A self-announce transmission is a broadcast for other pilots' situational awareness; it does not require a response, and none is shown in the examples in this subparagraph.

4.g.(2) When an airport's control tower is temporarily closed, or operates part-time and there is no FSS on the airport or the FSS is closed, each pilot WILL use the CTAF to self-announce position and intentions.

4.g.(3) Where an airport has no tower, FSS, or UNICOM station, each pilot WILL use MULTICOM frequency 122.9 MHz for self-announce procedures.

Note: An airport with no tower, FSS, or UNICOM station is identified as such in the applicable aeronautical publication.

4.g.(4) When a pilot elects to fly a straight-in approach to an airport without an operating control tower, that pilot SHOULD self-announce position on the CTAF approximately 8 to 10 NM from the airport and coordinate the approach and landing with other traffic.

Note: A straight-in approach carries an increased risk of a midair collision compared to a standard traffic pattern entry. See also paragraph 4.21.e, Straight-In Approaches, for the general permission to fly a straight-in approach and for the towered-airport request procedure.

Example: Self-Announce, Straight-In Approach Pilot: "Strawn traffic, Skyhawk Four Two Bravo, ten miles northeast, straight in runway three five, Strawn."

4.g.(5) While within 10 NM of a nontowered airport, or of a part-time-towered airport when the control tower is not operating, each pilot WILL monitor and communicate on the CTAF when entering the traffic pattern.

4.g.(6) Under the same condition, each pilot MUST remain alert for other aircraft in the pattern or conducting straight-in approaches.

4.g.(7) Under the same condition, each pilot MUST communicate position to avoid a traffic conflict.

4.g.(8) When conducting a practice instrument approach to an airport without an operating control tower, regardless of the approach's direction relative to other airport operations, the pilot WILL make a self-announce broadcast on the CTAF at each of the following points:

4.g.(8)(a) Departing the final approach fix inbound, for a nonprecision approach, or departing the outer marker or the fix used in lieu of the outer marker inbound, for a precision approach;

4.g.(8)(b) Established on the final approach segment, or immediately upon being released by ATC;

4.g.(8)(c) Upon completion or termination of the approach; and

4.g.(8)(d) Upon executing the missed approach procedure.

Example: Self-Announce, Practice Instrument Approach, Departing the Fix and Completing the Approach Pilot (departing the final approach fix): "Strawn traffic, Cessna Two One Four Three Quebec, five miles northwest, descending through three thousand, practice ILS approach runway three five, Strawn." Pilot (upon completion or termination): "Strawn traffic, Cessna Two One Four Three Quebec, practice ILS approach completed, runway three five, Strawn."

Example: Self-Announce, Practice Instrument Approach, Final Segment and Missed Approach Pilot (established on final approach segment): "Strawn traffic, Cessna Two One Four Three Quebec, established on the final approach course, practice ILS approach runway three five, Strawn." Pilot (executing the missed approach): "Strawn traffic, Cessna Two One Four Three Quebec, executing the missed approach, runway three five, Strawn."

4.g.(9) When conducting a practice instrument approach to an airport without an operating control tower, the pilot MUST remain particularly alert for other aircraft that may be departing in the opposite direction.

4.g.(10) After departing an airport without an operating control tower, each pilot MUST remain alert for arriving aircraft coming from the opposite direction.

4.g.(11) Each pilot WILL state the airport name at the beginning and end of every self-announce transmission.

Note: More than one airport may share the same UNICOM or MULTICOM frequency; stating the airport name at both ends of the transmission distinguishes one airport's traffic from another's.

Example: Self-Announce, Inbound Pilot: "Strawn traffic, Apache Two Two Five Zulu, (position), (altitude), entering downwind/base/final [as appropriate] runway one seven, full stop/touch-and-go, Strawn."

Example: Self-Announce, Outbound Pilot (taxiing): "Strawn traffic, Queen Air Seven One Five Five Bravo, (location on airport), taxiing to runway two six, Strawn." Pilot (departing): "Strawn traffic, Queen Air Seven One Five Five Bravo, departing runway two six, departing the pattern to the (direction), climbing to (altitude), Strawn."

4.h. UNICOM Communication Procedures.

4.h.(1) When communicating with a UNICOM station, each pilot WILL: (a) select the correct UNICOM frequency; (b) state the identification of the UNICOM station being called in each transmission; and (c) speak slowly and distinctly.

4.h.(2) Approximately 10 NM from the airport, each pilot WILL report to the UNICOM station the pilot's altitude, aircraft type, aircraft identification, position relative to the airport, and whether landing or overflying, and WILL request wind information and the runway in use.

4.h.(3) While in the traffic pattern, each pilot WILL report to the UNICOM station on downwind, base, and final approach.

4.h.(4) Upon leaving the runway, each pilot WILL report to the UNICOM station clear of the runway.

Example: UNICOM Communication, Inbound Pilot: "Frederick UNICOM, Cessna Eight Zero One Tango Foxtrot, ten miles southeast, descending through (altitude), landing Frederick, request wind and runway information, Frederick." UNICOM: [states wind and the runway in use] Pilot: "Frederick traffic, Cessna Eight Zero One Tango Foxtrot, entering downwind/base/final [as appropriate] for runway one niner, full stop/touch-and-go, Frederick." Pilot: "Frederick traffic, Cessna Eight Zero One Tango Foxtrot, clear of runway one niner, Frederick."

Example: UNICOM Communication, Outbound Pilot: "Frederick UNICOM, Cessna Eight Zero One Tango Foxtrot, (location on airport), taxiing to runway one niner, request wind and traffic information, Frederick." UNICOM: [states wind and traffic information] Pilot: "Frederick traffic, Cessna Eight Zero One Tango Foxtrot, departing runway one niner, remaining in the pattern [or] departing the pattern to the (direction) [as appropriate], Frederick."

4.5 Automatic Terminal Information Service (ATIS)

This paragraph establishes the content, service volume, and acknowledgment procedures for ATIS, the continuous recorded broadcast of noncontrol airport information that Approach and Tower use to reduce frequency congestion.

5.a. Service Volume.

5.a.(1) An arrival ATIS broadcast's protected service volume extends from 20 NM to 60 NM from the ATIS site, up to 25,000 ft above ground level (AGL).

5.a.(2) A departure ATIS broadcast's protected service volume does not exceed 5 NM from the ATIS site, up to 100 ft AGL.

Note: At most locations, ATIS can be received on the airport surface, but local terrain and antenna siting may reduce the usable range or altitude below these values.

5.b. Broadcast Content.

5.b.(1) On each ATIS broadcast, Approach or Tower WILL state the airport or facility name, the phonetic letter code identifying that broadcast, the time of the latest weather sequence in coordinated universal time (UTC), wind direction and velocity, visibility, obstructions to vision, sky condition, temperature, dew point, the altimeter setting, and a density altitude advisory (discretion, when density altitude conditions warrant), plus the instrument approach and runway in use.

5.b.(2) When the ceiling is above 5,000 ft AGL and the visibility is more than 5 statute miles (SM), Approach or Tower MAY omit the sky condition, ceiling, visibility, and obstructions to vision from the broadcast.

5.b.(3) When the ceiling is at or below 5,000 ft AGL, or the visibility is 5 SM or less, Approach or Tower WILL include the sky condition, ceiling, visibility, and obstructions to vision in the broadcast.

Note: The absence of a sky condition, ceiling, or visibility statement on an ATIS broadcast indicates a ceiling at or above 5,000 ft AGL and visibility of 5 SM or greater.

5.b.(4) When the departure runway differs from the runway in use for landing, or a separate departure ATIS broadcast exists, Approach or Tower WILL state the departure runway in the broadcast.

5.b.(5) When the departure runway is identical to the runway in use for landing and no separate departure ATIS broadcast exists, Approach or Tower MAY omit the departure runway from the broadcast.

5.b.(6) On receipt of an official hourly or special weather observation, Approach or Tower WILL record a new ATIS broadcast.

5.b.(7) On a change in other pertinent data, such as a runway change or a change in the instrument approach in use, Approach or Tower WILL record a new ATIS broadcast.

5.c. Pilot Acknowledgment.

5.c.(1) Whenever ATIS is in operation, pilots SHOULD monitor the ATIS broadcast before initial contact with Approach, Tower, or Ground.

5.c.(2) On initial contact with Approach, Tower, or Ground, each pilot WILL acknowledge the current ATIS broadcast by repeating its phonetic letter code.

Example: ATIS Acknowledgment on Initial Contact Pilot (initial contact with Approach): "Approach, Reach Three One, with information Sierra." Approach: [continues with instructions, omitting items already contained in information Sierra]

5.c.(3) When a pilot's initial contact omits acknowledgment of the current ATIS broadcast, or acknowledges an outdated broadcast, Approach, Tower, or Ground WILL provide that pilot the full current airport and weather information.

5.d. Rapidly Changing Conditions.

5.d.(1) When ceiling, visibility, altimeter, wind, or other conditions change faster than the recorded ATIS broadcast can be updated, Approach or Tower WILL issue the current values directly to the pilot rather than wait for a new recording.

Example: Rapidly Changing Conditions Advisory ATIS broadcast: "...latest ceiling, visibility, altimeter, and wind will be issued by approach control." Approach (initial contact): "Reach Three One, Approach, wind two two zero at one five gusting two five, altimeter three zero zero one."

5.e. HAVE NUMBERS.

5.e.(1) The report HAVE NUMBERS indicates receipt of wind, runway, and altimeter information only.

5.e.(2) When a pilot reports HAVE NUMBERS on initial contact, that pilot MUST NOT use the report as a substitute for ATIS acknowledgment.

5.e.(3) When a pilot reports HAVE NUMBERS on initial contact, Approach, Tower, or Ground WILL treat the report as receipt of wind, runway, and altimeter information only, not as ATIS acknowledgment.

Example: HAVE NUMBERS Report Pilot (initial contact with Clearance Delivery): "Clearance Delivery, Reach Three One, have numbers, ready to copy." Clearance Delivery: [issues clearance in full; does not omit ATIS-covered items on the basis of this report]

5.f. Flight Service Station Override on VOR Frequencies.

5.f.(1) At en route very high frequency (VHF) omnidirectional range (VOR) stations used as ATIS voice outlets, the FSS WILL transmit on that VOR's voice frequency to reach frequency-limited aircraft, interrupting the ATIS broadcast.

5.f.(2) When an aircraft can receive Flight Service Station transmissions on a frequency other than the VOR voice frequency, the pilot SHOULD monitor that other frequency, to keep ATIS override interruptions to a minimum.

4.6 Radar Traffic Information Service

This paragraph establishes how a controller at a radar-equipped facility issues traffic information to alert a pilot to a radar target that may conflict with the pilot's position or intended route, and the pilot's responsibilities under that service.

6.a. Pilot Responsibility. Regardless of any traffic information issued under this paragraph, each pilot remains bound by the visual scanning and collision-avoidance duty established in paragraph 4.41.f, Visual Scanning for Collision Avoidance.

6.b. Availability of the Service.

6.b.(1) The controller retains sole discretion whether to provide or continue traffic information, based on radar limitations, traffic volume, controller workload, and communications frequency congestion.

6.b.(2) The controller need not state or justify a decision to decline or discontinue traffic information.

6.b.(3) The controller will provide traffic information to each aircraft operating on an IFR flight plan, except when the pilot declines the service or the aircraft is operating within Class A airspace.

6.b.(4) The controller may provide traffic information to a flight not operating on an IFR flight plan when the pilot requests it.

Note: A radar facility normally displays and monitors primary radar, secondary (transponder) radar, and Automatic Dependent Surveillance-Broadcast (ADS-B) together. Secondary radar or ADS-B alone may serve as the sole display source in Class A airspace, in en route areas beyond primary coverage, or when the primary radar is temporarily out of service. The controller advises pilots on frequency of a temporary primary radar outage.

Example: Primary Radar Outage Advisory Controller: "Primary radar out of service, traffic advisories available on transponder or ADS-B aircraft only."

6.c. VFR Radar Advisory Service.

6.c.(1) While receiving VFR radar advisory service, the pilot should monitor the assigned frequency.

6.c.(2) The controller will provide a vector around conflicting traffic under VFR radar advisory service only when the pilot requests one.

6.c.(3) Before changing frequencies, the pilot will advise the controller that VFR radar advisory service is no longer desired.

6.c.(4) After being released from VFR radar advisory service, the pilot will reset the transponder code to 1200 if the aircraft is so equipped.

6.c.(5) While receiving VFR radar advisory service, the pilot will advise the controller before changing VFR cruising altitude.

6.c.(6) Except in a program where radar service terminates automatically, the controller will advise the pilot when radar service is terminated.

Example: Terminating VFR Radar Advisory Service Pilot: "Cancel flight following, changing to advisory frequency." Controller: "Radar service terminated, squawk VFR, frequency change approved."

6.d. Content of Traffic Information, Radar-Identified Target. For a target that is radar identified, the controller will state azimuth from the aircraft in terms of the 12-hour clock, distance from the aircraft in NM, the direction the target is proceeding, and the target's aircraft type and altitude if known.

6.d.(1) When a rapidly maneuvering civil test or military aircraft prevents accurate issuance of clock position, the controller will instead state direction from the aircraft's position using the eight cardinal compass points: north (N), northeast (NE), east (E), southeast (SE), south (S), southwest (SW), west (W), and northwest (NW).

6.d.(2) The pilot may request that the controller terminate use of the cardinal-compass method.

Example: Traffic Advisory, Radar-Identified Target Controller: "Traffic, ten o'clock, three miles, west-bound, type and altitude unknown."

6.d.(3) When issuing traffic information containing unverified Mode C altitude, the controller will state the target's indicated altitude.

Note: A Mode C (altitude-reporting transponder) readout is not valid for separation until verified, normally by comparing it to a pilot-stated altitude or, for an aircraft on the airport, to field elevation. An altitude issued in a traffic advisory before this comparison is indicated, not verified.

6.d.(4) The pilot may request a vector to avoid a target issued under this subparagraph.

6.d.(5) When the target lies within the airspace under that controller's jurisdiction, the controller will provide the requested vector to the extent possible.

6.d.(6) When the target lies outside that airspace, the controller will not provide the requested vector.

Example: Pilot Request for Vector Around Traffic Pilot: "Request vector to avoid traffic." Controller: "Turn left heading two seven zero, vector for traffic."

6.e. Content of Traffic Information, Non-Radar-Identified Target. For a target that is not radar identified, the controller will state distance and direction with respect to a fix, the direction the target is proceeding, and the target's aircraft type and altitude if known.

Example: Traffic Advisory, Non-Radar-Identified Target Controller: "Traffic, eight miles south of the airport, northeast-bound, type and altitude unknown."

6.f. Positional Accuracy. Whenever wind correction (crab) is required to hold a track, the pilot should expect that a target's actual visual position may differ from its issued clock position.

Note: The controller derives a target's azimuth from its track over the ground, not from its heading, so a crab angle needed to hold that track offsets the visually observed position from the issued clock position. This discrepancy does not occur when heading and track coincide.

4.7 Safety Alert

This paragraph establishes when a controller must issue a safety alert to the pilot of an aircraft under ATC control, and states the pilot's authority to respond.

When a controller is aware that an aircraft under that controller's control is at an altitude that, in the controller's judgment, places the aircraft in unsafe proximity to terrain, obstructions, or other aircraft, the controller will issue a SAFETY ALERT to the pilot.

Note: Issuance of a safety alert depends on the controller's awareness of the unsafe proximity condition and is not a guaranteed service; a pilot can reasonably expect it on an intermittent basis rather than in every case. This paragraph applies to time-critical situations only; noncritical traffic situations are handled under the traffic advisory procedures of paragraph 4.6, Radar Traffic Information Service.

After a controller issues a SAFETY ALERT, the pilot may determine what course of action, if any, to take in response.

7.a. Terrain or Obstruction Alert.

7.a.(1) When a controller recognizes that an aircraft under the controller's control is at an altitude that, in the controller's judgment, may be in unsafe proximity to terrain or obstructions, the controller will immediately issue a LOW ALTITUDE ALERT to the pilot. Detection is primarily through Mode C automatic altitude reports.

Example: Low Altitude Alert Sender: Controller. Condition: Aircraft altitude judged unsafe relative to terrain or obstructions. Controller: "LOW ALTITUDE ALERT, Cessna Three Four Juliett, check your altitude immediately. The MVA in your area is 6,000 ft MSL." Required response: None specified. The pilot determines the corrective action.

Note: "MVA" (Minimum Vectoring Altitude) is stated, or, where applicable, the Minimum En Route Altitude (MEA), Minimum IFR Altitude (MIA), or Minimum Obstruction Clearance Altitude (MOCA) for the pilot's area.

7.a.(2) When Minimum Safe Altitude Warning (MSAW) processing is operating at the facility, the facility will provide MSAW monitoring for each aircraft with an operating Mode C altitude-encoding transponder that is tracked by the system and is operating on an IFR flight plan.

7.a.(3) A pilot operating under VFR with an operating Mode C transponder may request MSAW monitoring from the controller. Otherwise, MSAW monitoring is not provided for that flight.

Example: VFR MSAW Monitoring Request Sender: Pilot. Condition: Pilot desires MSAW monitoring while operating VFR. Pilot: "Apache Three Three Papa, request MSAW monitoring." Required response: Controller acknowledges whether monitoring is provided.

Note: Near the United States border with Mexico and Canada, accurate terrain and obstacle clearance data may not be available to the facility's automation database, and MSAW computer processing may be inhibited as a result. A pilot operating in these areas should not assume MSAW monitoring is active.

7.b. Aircraft Conflict Alert.

7.b.(1) When a controller is aware of another aircraft, not under that controller's control, at an altitude that, in the controller's judgment, places both aircraft in unsafe proximity to each other, the controller will immediately issue a TRAFFIC ALERT to the pilot of the aircraft under the controller's control. When time permits, the controller will include the traffic's position and an alternate course of action; any alternate course of action recommended is based only on other traffic the controller is working.

Example: Traffic Alert Sender: Controller. Condition: Unsafe proximity to traffic not under the controller's control. Controller: "American Three, TRAFFIC ALERT, (position of traffic, if time permits), advise you turn right/left heading (degrees) and/or climb/descend to (altitude) immediately." Required response: None specified. The pilot determines the corrective action.

4.8 Radar Assistance to VFR Aircraft

This paragraph establishes when a radar-equipped ATC facility provides navigational vectors to VFR aircraft, the advisory nature of that assistance, and the discretion a controller retains to decline it.

8.a. Service Eligibility. When a VFR aircraft can communicate with a radar-equipped ATC facility, is within that facility's radar coverage, and can be radar identified, the facility will provide radar navigation assistance (vectors) to the aircraft.

8.b. Advisory Nature of Vectors.

8.b.(1) When following a controller's radar vector, the pilot remains bound by the deviation-authority limits established in paragraph 4.29.a(2), Clearance; a vector does not authorize deviation from the Code of Federal Regulations (CFR).

8.b.(2) When accepting radar navigational guidance, the pilot retains sole responsibility for the safe operation of the aircraft.

Note: Radar navigational guidance issued under this paragraph is advisory. The controller's role is limited to providing guidance information and does not carry command authority over the aircraft's flight path.

8.c. Weather Advisories. When operating under VFR radar assistance, the pilot should advise the controller of the weather conditions in which the aircraft is operating and along the course ahead, to avoid being vectored into IFR conditions.

Note: A controller cannot always determine, from the instructions issued, whether a VFR aircraft will be vectored into instrument conditions. The pilot's own weather reports are the safeguard against that outcome.

Example: Weather Advisory During Vectors Condition: The pilot observes cloud along the assigned heading that will require entry into instrument meteorological conditions to remain on course. Pilot: "Approach, Cessna Three Four Six Tango, VFR, showing a solid cloud layer along this heading, UNABLE to remain clear of clouds on present heading." Approach: "Cessna Three Four Six Tango, ROGER, turn left heading two seven zero, advise if that keeps you clear."

8.d. Controller-Initiated Vectors. When any of the following conditions exist, a controller may initiate a radar vector to a VFR aircraft: (1) the controller suggests the vector and the pilot concurs; (2) an established special program has advertised vectoring service; or (3) the controller judges the vector necessary for air safety.

Example: Controller-Suggested Vector Condition: The controller identifies a benefit to the VFR flight, such as traffic sequencing, and offers a vector under d.(1). Approach: "Cessna Three Four Six Tango, I can vector you around traffic for sequencing, advise if you'd like a heading." Pilot: "Cessna Three Four Six Tango, AFFIRMATIVE, request vectors." Approach: "Cessna Three Four Six Tango, fly heading three one zero."

8.e. Pilot-Requested Vectors.

8.e.(1) When a pilot requests radar navigation assistance (vectors) or other radar-derived information, a controller may provide it.

8.e.(2) When radar limitations, traffic volume, communications frequency congestion, or controller workload could prevent providing a requested service, each controller retains discretion to determine whether the service can be provided in that case.

8.e.(3) When a controller declines a requested vector or radar-derived information, the pilot must not dispute that decision.

Example: Pilot-Requested Vector, Declined Condition: The pilot requests navigational assistance not already offered by the controller. Pilot: "Approach, Cessna Three Four Six Tango, request vectors around the weather ahead." Approach: "Cessna Three Four Six Tango, UNABLE at this time due to workload, maintain present heading, advise intentions."

4.9 Terminal Radar Services for VFR Aircraft

This paragraph establishes the basic radar, Terminal Radar Service Area (TRSA), Class C, and Class B services a radar facility provides to VFR aircraft, and the pilot's continuing responsibilities while receiving them.

9.a. Basic Radar Service. In addition to IFR traffic control, each commissioned radar facility WILL provide every VFR aircraft in contact with it: (1) safety alerts (paragraph 4.7); (2) traffic advisories (paragraph 4.6); (3) limited radar vectoring (paragraph 4.8), workload permitting; and (4) sequencing, where a local procedure or an LOA establishes it.

9.b. Terminal Radar Service Area (TRSA) Service.

9.b.(1) Where a TRSA is established, Approach Control WILL offer radar sequencing and separation service (TRSA service) between IFR aircraft and all participating VFR aircraft within the TRSA. Pilot participation is voluntary.

9.b.(2) On initial contact with Approach Control, or with Ground Control before departure, a pilot who does not want TRSA service SHOULD state NEGATIVE TRSA SERVICE, or a similar statement of refusal.

Example: TRSA Service Declination Pilot: "NEGATIVE TRSA SERVICE."

9.b.(3) On loss of the radar supporting TRSA service, Approach Control WILL suspend TRSA sequencing and separation, advise the pilot that the service is unavailable, and issue wind, runway information, and the time or place to contact Tower. Approach Control WILL continue traffic advisories on a workload-permitting basis.

9.b.(4) When a participating VFR aircraft's pilot reports a preceding aircraft in sight, Approach Control WILL instruct the pilot to follow it using visual separation.

Example: Visual Following Instruction Approach: "Cessna One Two Three Alpha Bravo, follow the Boeing Seven Three Seven ahead." Pilot: "Follow the Seven Three Seven, Cessna One Two Three Alpha Bravo."

Note: The general procedure for pilot-executed visual separation, including the pilot's obligation to report traffic IN SIGHT before accepting the instruction and to maintain constant visual surveillance afterward, is established in paragraph 4.41, Visual Separation.

9.b.(5) The pilot MUST NOT comply with any ATC clearance or instruction issued to the preceding aircraft on the basis of a visual following instruction alone.

9.b.(6) When a nonparticipating or local aircraft is also in the traffic pattern, Tower WILL issue a landing sequence.

9.b.(7) Approach Control MAY ask a departing VFR aircraft whether it can visually follow a preceding departure out of the TRSA.

9.b.(8) Approach Control WILL separate participating VFR aircraft from IFR aircraft, and from other participating VFR aircraft, by one of: 500 ft vertical separation, visual separation, or target resolution.

9.b.(9) The pilot MUST maintain an ATC-assigned altitude, except that an assignment to maintain at or below a specified altitude permits any altitude at or below it. When not assigned an altitude, the pilot SHOULD coordinate with Approach Control before changing altitude.

9.b.(10) Approach Control WILL provide traffic information on observed, unidentified radar targets to all IFR and participating VFR aircraft, workload permitting.

9.b.(11) A departing pilot SHOULD inform Approach Control of intended destination, route of flight, and proposed cruising altitude.

9.b.(12) On leaving the TRSA's lateral limits, Approach Control WILL advise the participating VFR aircraft. TRSA service continues past that advisory unless Approach Control states that the service is terminated.

9.c. Class C Service. In Class C airspace, Approach Control WILL provide, in addition to basic radar service, approved separation between IFR and VFR aircraft and sequencing of VFR arrivals to the primary airport.

9.d. Class B Service. In Class B airspace, Approach Control WILL provide, in addition to basic radar service, approved separation based on IFR status, VFR status, and/or aircraft weight category, and sequencing of VFR arrivals to the primary airport or airports.

9.e. Pilot Responsibility. Regardless of any basic radar, TRSA, Class C, or Class B service received under this paragraph:

9.e.(1) each pilot MUST continue to see and avoid other traffic while operating in visual meteorological conditions (VMC), per the visual scanning duty established in paragraph 4.41.f, Visual Scanning for Collision Avoidance;

9.e.(2) each pilot retains discretion to adjust flight path to avoid a wake turbulence encounter;

9.e.(3) each pilot MUST maintain appropriate terrain and obstruction clearance; and

9.e.(4) each pilot MUST remain in weather conditions equal to or better than the VFR minimums required by 14 CFR Section 91.155.

9.f. Radar Dependency. All VFR terminal radar services under this paragraph depend on ATC radar and WILL NOT be provided during a radar outage; see subparagraph b.(3) for the TRSA outage procedure. The radar facility WILL advise the pilot when limited or unavailable.

B. Radio Communications Phraseology and Techniques (Paragraphs 4.10–4.19)

4.10 Radio Technique

This paragraph establishes radio operating practices for aircraft transmissions on ATC frequencies.

10.a. Before transmitting on any frequency, the pilot WILL listen to confirm the frequency is clear.

Note: Monitoring the ATIS broadcast or the ongoing frequency traffic often provides the needed information without transmitting.

10.b. Immediately after switching to a new frequency, the pilot WILL pause and listen before transmitting to confirm the new frequency is clear.

Note: A transmission keyed over another station's transmission will not be heard by the receiving facility and typically forces the other station to repeat its call. A small number of frequencies are configured with overlap and can receive more than one transmission at once; this exception does not apply to standard single-frequency operations.

10.c. Before keying the transmitter for a lengthy message, such as a flight plan or an IFR position report, the pilot SHOULD write out the content in advance.

Example: Prepared Position Report Pilot (report written out, frequency confirmed clear): "Center, November One Two Three Alpha Bravo, position report. [Fix], zero one five zero Zulu, flight level three five zero." Center: acknowledges the report and issues any amended clearance.

10.d. When transmitting, the pilot WILL observe the following microphone technique: (1) position the microphone close to the lips; (2) pause briefly after pressing the microphone button before speaking, to ensure the first word is transmitted; and (3) speak in a normal conversational tone.

10.e. After releasing the transmitter button, the pilot WILL wait several seconds before transmitting again.

Note: The controller or the FSS specialist may be recording the aircraft's identification, locating its flight plan, transmitting on another frequency, or selecting the transmitter assigned to this frequency.

10.f. When a frequency produces an unusual sound or an unexplained absence of sound, the pilot WILL check the radio volume, recheck the selected frequency, and confirm the microphone is not stuck in the transmit position.

Note: Frequency blockage from an unintentionally keyed transmitter is called a "stuck mike," and a controller advising other aircraft of the condition may use that term.

Example: Stuck Microphone Advisory Controller (on an alternate or guard frequency, addressing all aircraft): "Attention all aircraft, Center is receiving a stuck microphone on one three four point five. Aircraft transmitting, check your microphone." Affected pilot (if able to receive and transmit): confirms the microphone is not keyed and reestablishes the call-up once clear.

10.g. When the assigned frequency is completely blocked by a stuck microphone, the pilot MUST follow the communications-failure procedures established elsewhere in this publication for en route IFR operations.

10.h. When selecting or maintaining a frequency assignment, the pilot WILL confirm the transmission is within the performance range of both the aircraft radio equipment and the ground station equipment.

Note: A remote radio site does not always transmit and receive on every frequency assigned to its parent facility, and a VOR site in particular may be receivable without being able to receive the pilot's transmission in return. Higher altitude increases the range of very high frequency (VHF) line-of-sight communications.

4.11 Contact Procedures

This paragraph establishes the format for the pilot's initial and subsequent radio contact with each facility (Clearance Delivery, Ground, Tower, Departure, Approach, Center, or an FSS), and the acknowledgement the pilot owes ATC or an FSS specialist when the assigned frequency changes.

11.a. Initial Contact.

11.a.(1) On an initial contact, meaning the pilot's first transmission to a given facility or the first transmission to a different controller or FSS specialist within that facility, the pilot WILL transmit, in this order: (i) the name of the facility being called; (ii) the pilot's full aircraft identification as filed in the flight plan (see paragraph 4.12, Aircraft Call Signs); (iii) the aircraft's position, if operating on an airport surface; (iv) the type of message or the pilot's request, if it is short; and (v) the word OVER, when required.

Note: This paragraph does not define when the word OVER is required; the determination is at the pilot's discretion.

Example: Initial Callup, FSS Contact, En Route Pilot: "New York Radio, Mooney Three One One Echo."

Example: Initial Callup, Ground Contact, IFR Departure Pilot: "Columbia Ground, Cessna Three One Six Zero Foxtrot, south ramp, IFR Memphis."

Example: Initial Callup, Center Contact, VFR Advisories Request Pilot: "Miami Center, Baron Five Six Three Hotel, request VFR traffic advisories."

11.a.(2) When more than one Remote Communications Outlet (RCO) transmits the same frequency for a Flight Service Station, the pilot WILL state the name of the VOR station on which the pilot is receiving.

Note: Many FSSs are equipped with RCOs and can transmit on the same frequency from more than one location.

Example: Initial Callup, RCO Reception Pilot: "Saint Louis Radio, Piper Six Niner Six Yankee, receiving Decatur One Two Two Point Three."

11.a.(3) When the pilot reasonably expects reliable radio reception, the pilot MAY include the request, the position or altitude, and, if applicable, the phrase "INFORMATION [phonetic letter] RECEIVED" (ATIS) in the initial contact call. The pilot SHOULD NOT include information that is unneeded or superfluous.

Note: Combining this information into the initial contact, rather than a separate transmission, reduces radio frequency congestion.

Example: Initial Callup, Combined Information Pilot: "Atlanta Center, Duke Four One Romeo, request VFR traffic advisories, twenty northwest Rome, seven thousand five hundred, over."

11.b. Differing Transmit and Receive Frequencies.

11.b.(1) When the pilot is attempting to establish contact with a ground station and is receiving on a frequency different from the frequency transmitted, the pilot WILL indicate the VOR name or the frequency on which the pilot expects a reply. The pilot WILL use the FSS call sign shown on the chart for that VOR.

Note: Most FSSs and control facilities can transmit on several VOR stations in the area they serve.

Example: Initial Callup, Differing Transmit/Receive Frequency Pilot (in the Calverton area, New York FSS): "New York Radio, Cessna Three One Six Zero Foxtrot, receiving Calverton VOR, over."

11.b.(2) When the chart shows FSS frequencies above the VOR/TACAN (VORTAC) or in the FSS communications boxes, the pilot WILL transmit or receive on the frequency nearest the pilot's location.

11.b.(3) When the pilot is unable to establish contact and wishes to call any ground station, the pilot WILL use the phrase ANY RADIO, as shown below. The pilot MUST state an emergency or a need for assistance, if either exists.

Example: Any-Radio Callup Pilot: "ANY RADIO (tower) (station), GIVE CESSNA THREE ONE SIX ZERO FOXTROT A CALL ON (frequency) OR (VOR)."

11.c. Subsequent Contact and Callup Response.

11.c.(1) On any transmission after the initial contact, the pilot WILL use the initial-contact format described in subparagraph a. The pilot WILL state the message or request together with the callup, in one transmission.

11.c.(2) When the message requires an obvious reply and there is no possibility of misunderstanding, the pilot MAY omit the ground station name and the word OVER.

11.c.(3) On any callup or clearance from a controller or FSS specialist, the pilot SHOULD acknowledge it, unless the controller or FSS specialist advises otherwise.

Note: A controller may need to issue time-critical instructions to other aircraft while observing the pilot's response visually or on radar.

11.c.(4) When the situation demands the pilot's response, the pilot MUST take appropriate action or immediately advise the facility of any problem.

11.c.(5) When acknowledging a callup or clearance, the pilot WILL identify with the aircraft identification, at the beginning or the end of the transmission, together with one of the words WILCO, ROGER, AFFIRMATIVE, NEGATIVE, or another appropriate remark.

Example: Acknowledgement Pilot: "Piper Two One Four Lima, ROGER."

11.c.(6) When the pilot has been receiving services such as VFR traffic advisories and is leaving the area or changing frequencies, the pilot WILL advise the ATC facility and terminate contact.

11.d. Frequency-Change Acknowledgement.

11.d.(1) When ATC advises the pilot to change frequencies, the pilot WILL acknowledge the instruction.

Note: A pilot who selects the new frequency without acknowledging increases the controller's workload, because the controller then cannot know whether the pilot received the instruction or experienced a radio communications failure.

11.d.(2) When a controller or FSS specialist is working a sector with multiple frequency assignments, the controller or FSS specialist MAY direct the pilot to change frequency using abbreviated phraseology.

Note: Abbreviated phraseology eliminates unnecessary verbiage and frees the controller or FSS specialist for higher-priority transmissions.

Example: Abbreviated Frequency-Change Instruction Controller or FSS Specialist: "(Identification), change to my frequency, one three four point five." Pilot: "United Two Twenty-Two on one three four point five." or "One three four point five, United Two Twenty-Two."

Note: This abbreviated phrase signals to the pilot that only the frequency is changing, that the same controller or FSS specialist remains assigned, and that the pilot's callup on the new frequency may likewise be abbreviated.

11.e. Frequency-Change Compliance.

11.e.(1) When ATC instructs the pilot to change frequencies, the pilot WILL select the new frequency as soon as possible, unless ATC instructs the pilot to make the change at a specific time, fix, or altitude.

Note: A delay in changing frequency could cause the pilot to receive important information late.

11.e.(2) When ATC instructs the pilot to make the frequency change at a specific time, fix, or altitude, the pilot WILL monitor the frequency currently in use until reaching that time, fix, or altitude, unless ATC instructs otherwise.

Note: See paragraph 5.15, ARTCC (Center) Communications, for related frequency-monitoring guidance during en route flight.

4.12 Aircraft Call Signs

This paragraph establishes the call sign formats used by civil, air taxi, air carrier, military, air ambulance, and student pilot flights, and states how the pilot and the controlling facility (Clearance Delivery, Ground, Tower, Departure, Approach, Center, or an FSS) act to prevent confusion between aircraft with similar call signs.

12.a. Call Sign Confusion.

12.a.(1) When another aircraft on the frequency has a call sign with similar numbers or sounds, or with identical letters or numbers, the pilot and the controlling facility must not abbreviate either aircraft's call sign, on initial contact or at any other time.

Example: Similar Call Signs Cessna 6132F, Cessna 1622F, Baron 123F, Cherokee 7732F.

Note: An aircraft whose call sign resembles another aircraft's call sign may acknowledge a clearance intended for the other aircraft by reading back only the last two or three digits or letters of its own call sign, and neither the pilot nor the controlling facility receiving that readback has reason to suspect an error has occurred.

12.a.(2) When an air carrier or other civil aircraft holds a call sign authorized by the Federal Aviation Administration (FAA), the controlling facility will not abbreviate that call sign.

12.a.(3) Once two-way communications are established with an aircraft that does not hold an FAA-authorized call sign, the controlling facility may initiate an abbreviated call sign using the prefix and the last three digits or letters of the aircraft's identification.

12.a.(4) After the controlling facility initiates an abbreviated call sign under (3) above, the pilot may use that abbreviated call sign in subsequent transmissions to the controlling facility.

12.a.(5) When the controlling facility is aware that two call signs on the frequency are similar or identical, the controlling facility will act to minimize errors, by emphasizing specific numbers or letters, by repeating the entire call sign, by repeating the prefix, or by asking a pilot to use a different call sign temporarily.

12.a.(6) When the pilot is in doubt about the identity of an aircraft addressed in a clearance, the pilot should use the phrase "VERIFY CLEARANCE FOR" followed by the pilot's complete call sign.

Example: Verify Clearance Phraseology Pilot (doubt exists as to which aircraft a clearance addressed): "VERIFY CLEARANCE FOR November One Two Three Four Alpha."

12.b. Civil Aircraft Call Sign Format.

12.b.(1) When identifying a civil aircraft, the pilot should state the aircraft type, model, or manufacturer's name, followed by the digits or letters of the registration number.

12.b.(2) When the pilot states the aircraft manufacturer's name or model under (1) above, the pilot will omit the registration prefix "N."

Example: Civil Aircraft Call Signs Aztec Two Four Six Four Alpha. Bonanza Six Five Five Golf. Breezy Six One Three Romeo EXPERIMENTAL.

12.b.(3) After the initial contact, the pilot of an aircraft carrying the term EXPERIMENTAL will omit that term from the call sign.

12.c. Air Taxi and Other Commercial Operator Call Signs.

12.c.(1) When an air taxi or other commercial operator does not hold an FAA-authorized call sign, the pilot should prefix the aircraft's normal identification with the phonetic word TANGO.

Example: Tango Prefix TANGO Aztec Two Four Six Four Alpha.

12.d. Air Carrier and Commuter Air Carrier Call Signs.

12.d.(1) When identifying an air carrier or commuter air carrier flight that holds an FAA-authorized call sign, the pilot should state the complete call sign, using group form for the numbers.

12.d.(2) When the aircraft's weight class requires it, the pilot should append the word SUPER or HEAVY to the call sign under (1) above; otherwise, the pilot omits it.

Example: Air Carrier Call Signs United Twenty-Five HEAVY. Midwest Commuter Seven Eleven.

Note: The weight-class criteria that determine when SUPER or HEAVY applies to a given aircraft type are not stated in this paragraph. [VERIFY: weight-class thresholds triggering the SUPER or HEAVY call sign designation.]

12.e. Military Aircraft Call Signs.

12.e.(1) When identifying a military aircraft, the pilot must use the call sign assigned by the aircraft's parent military service, in the form of a serial number, an assigned word call sign, or a combination of letters and numbers.

Example: Military Call Sign Forms Army Copter 48931. Air Force 61782. REACH 31792. Pat 157. Air Evac 17652. Navy Golf Alfa Kilo 21. Marine 4 Charlie 36.

12.f. Air Ambulance (MEDEVAC) Flights.

12.f.(1) When determining whether to use the term MEDEVAC, the pilot must reserve it for flights of an urgent medical nature.

12.f.(2) On a flight using the term MEDEVAC, the pilot must limit its use to the portion of the flight that requires priority handling.

12.f.(3) To receive priority handling from the controlling facility, the pilot must verbally state MEDEVAC followed by the FAA-authorized call sign (an International Civil Aviation Organization (ICAO) three-letter designator (3LD), a United States (US) Special call sign, or a locally assigned call sign) or the aircraft's civil "N" registration number or letters.

Example: MEDEVAC Identification Aircraft identification DAL51: "MEDEVAC Delta Fifty One." Aircraft identification MDSTR1: "MEDEVAC Medstar One." Aircraft identification N123G or LN123G: "MEDEVAC One Two Three Golf."

12.f.(4) When the pilot requests it, the controlling facility will provide additional assistance, such as a landline notification, to expedite ground handling of patients, vital organs, or urgently needed medical materials; when the pilot does not request it, the controlling facility takes no additional action beyond the priority handling in (3) above.

12.f.(5) When making a request under (4) above, the pilot should use a method other than the ATC radio frequency, when possible.

12.f.(6) MEDEVAC flights include the following: (a) a civilian air ambulance flight responding to a medical emergency, including a first call to an accident scene or a flight carrying a patient, an organ donor, an organ, or other urgently needed lifesaving medical material; and (b) an air carrier or air taxi flight responding to a medical emergency, typically transporting urgently needed lifesaving medical material or a vital organ, which may also include an inflight medical emergency.

12.f.(7) When a flight carries medical cargo described in (6)(b) above, the pilot and the operating company must determine, based on the nature and urgency of the specific medical cargo, whether priority handling from the controlling facility is required.

12.f.(8) When filing a flight plan, the pilot may include the letter L for MEDEVAC with the aircraft's registration letters or digits, include the word MEDEVAC in Item 11 (Remarks) of the flight plan, or include it in Item 18 (Other Information) of an international flight plan.

12.f.(9) When a flight plan contains a MEDEVAC entry under (8) above, the controlling facility will use that entry only for informational purposes or as a visual indicator.

12.f.(10) Even when a flight plan contains a MEDEVAC entry under (8) above, the controlling facility will provide priority handling only when the pilot verbally identifies the flight's MEDEVAC status as required in (3) above.

Note: A civilian air ambulance aircraft operating under VFR without a filed flight plan remains eligible for priority handling under (3) above.

12.f.(11) When a pilot verbally requests it, the controlling facility will provide priority handling to a flight identified as HOSP or AIR EVAC.

12.f.(12) When filing a flight plan for a HOSP or AIR EVAC flight, the pilot may include the term HOSP or AIR EVAC in Item 11 (Remarks) of the flight plan or in Item 18 (Other Information) of an international flight plan.

12.f.(13) When identifying a HOSP flight in radio transmissions, a civilian pilot will use the flight's normal call sign.

12.f.(14) When identifying a HOSP or AIR EVAC flight in radio transmissions, a military pilot will use the call sign EVAC.

12.g. Student Pilot Radio Identification.

12.g.(1) On initial contact with Clearance Delivery prior to taxiing, Ground, Tower, Approach, Departure, or an FSS, a student pilot should identify as a STUDENT PILOT.

Example: Student Pilot Identification Student pilot (call sign "Fleetwing One Two Three Four"): "Dayton Tower, Fleetwing One Two Three Four, STUDENT PILOT."

Note: This identification alerts the receiving facility that the student pilot may need additional assistance and consideration.

4.13 Ground Station Call Signs

This paragraph establishes the standard format each pilot uses to address a ground station when initiating radio contact.

13.a. When initiating a call to a ground station, each pilot should state the name of the facility being called followed by the type of the facility being called, in the format shown in Table 13-1.

Table 13-1. Ground Station Call Signs by Facility Type

Facility Type	Call Sign Format
Airport UNICOM	"Shannon UNICOM"
FAA Flight Service Station	"Chicago Radio"
Airport Traffic Control Tower	"Augusta Tower"
Clearance Delivery position (IFR)	"Dallas Clearance Delivery"
Ground Control position in a tower	"Miami Ground"
Radar or nonradar Approach Control position	"Oklahoma City Approach"
Radar Departure Control position	"St. Louis Departure"
FAA Air Route Traffic Control Center	[VERIFY: exact call sign example for this row could not be retrieved from the fetched source]

Legend: FAA = Federal Aviation Administration. UNICOM = Universal Communications. IFR = Instrument Flight Rules.

Example: Initial Call to Ground Control Pilot (call sign "Falcon Two One"): "Miami Ground, Falcon Two One."

Example: Initial Call to Clearance Delivery Pilot (call sign "Reach Four Zero"): "Dallas Clearance Delivery, Reach Four Zero."

Example: Initial Call to a Flight Service Station Pilot (call sign "Cessna Four Five Six Seven X-ray"): "Chicago Radio, Cessna Four Five Six Seven X-ray."

4.14 Phonetic Alphabet

This paragraph establishes when the controller and the pilot use the ICAO phonetic alphabet on frequency, so that letters, numbers, and words that sound alike are not confused for one another.

14.a. When transmission conditions make information difficult to receive without it, or when a fix, waypoint, or word could otherwise be misunderstood, the controller and the pilot will use the ICAO phonetic alphabet, as shown in Table 14-1, to identify single letters, spell out groups of letters, and spell difficult words.

Example: Spelling a Fix Under Adverse Reception Denver Center: "November Four Five Two Seven Bravo, cleared direct KIPPR intersection, spelling follows, Kilo India Papa Papa Romeo, KIPPR." Pilot: "Cleared direct KIPPR, Kilo India Papa Papa Romeo, November Four Five Two Seven Bravo."

14.b. When two or more aircraft with similar-sounding identifications are receiving communications on the same frequency, the controller may request that each pilot use phonetic letter equivalents for the aircraft's identification.

Example: Distinguishing Similar Call Signs Ground: "November Two Three Four Sierra Papa and November Two Three Four Foxtrot Papa, use phonetic letters for your call signs on this frequency." Pilot (234SP): "November Two Three Four Sierra Papa, Sierra Papa, WILCO."

14.c. On initial contact with an air traffic control facility, each pilot should identify the aircraft using the phonetic alphabet.

Example: Initial Contact Pilot: "Springfield Tower, November Four Five Two Seven Bravo, ten miles east, landing." Springfield Tower: "November Four Five Two Seven Bravo, Springfield Tower, report right base runway two seven."

14.d. Table 14-1 sets out the telephony word and pronunciation the controller and the pilot use for each character under subparagraph a.

Table 14-1. Phonetic Alphabet and Morse Code

Character	Morse Code	Telephony	Phonic (Pronunciation)
A	● —	Alfa	AL-FAH
B	— ● ● ●	Bravo	BRAH-VOH
C	— ● — ●	Charlie	CHAR-LEE or SHAR-LEE
D	— ● ●	Delta	DELL-TAH
E	●	Echo	ECK-OH
F	● ● — ●	Foxtrot	FOKS-TROT
G	— — ●	Golf	GOLF
H	● ● ● ●	Hotel	HOH-TEL
I	● ●	India	IN-DEE-AH
J	● — — —	Juliett	JEW-LEE-ETT
K	— ● —	Kilo	KEY-LOH
L	● — ● ●	Lima	LEE-MAH
M	— —	Mike	MIKE
N	— ●	November	NO-VEM-BER
O	— — —	Oscar	OSS-CAH
P	● — — ●	Papa	PAH-PAH
Q	— — ● —	Quebec	KEH-BECK
R	● — ●	Romeo	ROW-ME-OH
S	● ● ●	Sierra	SEE-AIR-RAH
T	—	Tango	TANG-GO
U	● ● —	Uniform	YOU-NEE-FORM or OO-NEE-FORM
V	● ● ● —	Victor	VIK-TAH
W	● — —	Whiskey	WISS-KEY
X	— ● ● —	Xray	ECKS-RAY
Y	— ● — —	Yankee	YANG-KEY
Z	— — ● ●	Zulu	ZOO-LOO
1	● — — — —	One	WUN
2	● ● — — —	Two	TOO
3	● ● ● — —	Three	TREE
4	● ● ● ● —	Four	FOW-ER
5	● ● ● ● ●	Five	FIFE
6	— ● ● ● ●	Six	SIX
7	— — ● ● ●	Seven	SEV-EN
8	— — — ● ●	Eight	AIT
9	— — — — ●	Nine	NIN-ER
0	— — — — —	Zero	ZEE-RO

Legend: Character = the letter or numeral represented. Morse Code = the international Morse code symbol for that character (● = dot, — = dash). Telephony = the standard ICAO spoken word for that character. Phonic (Pronunciation) = the syllabic pronunciation guide for the telephony word, stressed syllable underlined in source publications.

Note: The controller and the pilot may use either accepted pronunciation of Charlie (CHAR-LEE or SHAR-LEE) and Uniform (YOU-NEE-FORM or OO-NEE-FORM) interchangeably.

4.15 Number Phraseology

This paragraph establishes how each pilot and each controller pronounces numbers on an ATC radio frequency, so that ceiling heights, wind levels, route designators, and other figures transmit without ambiguity.

15.a. When transmitting a ceiling height or an upper wind level expressed as a round number in the hundreds or thousands, up to 9,900, the pilot and each controller will speak the figure as a whole-number group ("hundred" or "thousand") rather than as separate digits.

Example: Round Number Transmission Figure 500: "Five hundred." Figure 4,500: "Four thousand five hundred."

15.b. When transmitting a number above 9,900, the pilot and each controller will pronounce each digit preceding the word "thousand" individually, then state the remainder as a round number.

Example: Number Above 9,900 Figure 10,000: "One zero thousand." Figure 13,500: "One three thousand five hundred."

15.c. When transmitting an airway or jet route number, the pilot and each controller will speak the route's letter designator followed by its number, pronounced as illustrated below.

Example: Airway and Jet Route Designators Route V12: "Victor twelve." Route J533: "J five thirty-three."

Note: The airway letter is spoken using its phonetic-alphabet equivalent (e.g., "Victor" for V), while the jet route letter "J" is spoken as the letter itself.

15.d. When transmitting any number not covered by subparagraph a, b, or c, the pilot and each controller will pronounce each digit individually.

Example: Individual Digit Transmission Figure 10: "One zero."

15.e. When transmitting a radio frequency that contains a decimal point, the pilot and each controller will speak the decimal point as "point."

Example: Frequency Transmission Frequency 122.1: "One two two point one."

Note: ICAO procedures require the decimal point to be spoken as "decimal" rather than "point." The FAA honors this usage by military aircraft and by any other aircraft required to operate under ICAO procedures, so a controller working mixed civil and military traffic should expect to hear both forms and must not treat "decimal" as a misread frequency.

4.16 Altitude and Flight Level Phraseology

This paragraph establishes how pilots and controllers state altitude and flight level values over radio so that numeric values are transmitted without ambiguity.

16.a. When transmitting an altitude below 18,000 feet MSL, the pilot or the controller will state the separate digits of the thousands, followed by the separate digits of the hundreds when the altitude includes a hundreds value.

Example: Altitude Assignment Below Flight Level 180 (FL180) Approach: "November Three Four Papa Tango, climb and maintain one two thousand five hundred." Pilot: "Climb and maintain one two thousand five hundred, November Three Four Papa Tango."

16.b. When transmitting an altitude at or above 18,000 feet MSL (flight level 180, FL180), the pilot or the controller will state the words "flight level" followed by the separate digits of the flight level.

Example: Altitude Assignment At or Above FL180 Center: "November Three Four Papa Tango, climb and maintain flight level one niner zero." Pilot: "Climb and maintain flight level one niner zero, November Three Four Papa Tango."

Note: Pilot readback of an altitude or flight level assignment follows the digit-grouping and flight-level phraseology in subparagraphs a and b above; the readback requirement itself is established in paragraph 4.34, Clearance Readback and Acceptance.

4.17 Direction Phraseology

This paragraph establishes the reference frame, magnetic or true, used when a bearing, course, heading, or wind direction is transmitted by radio.

17.a. When transmitting a bearing, course, heading, or wind direction by radio, the pilot and the controller will each state the value as three digits of degrees magnetic, as shown in Table 17-1.

17.b. When the bearing, course, or heading transmitted is degrees true rather than degrees magnetic, the pilot or the controller must add the word TRUE immediately following the three digits.

Table 17-1. Direction Types and Spoken Form

#	Type	Written Value	Spoken Form
1	Magnetic course	005	ZERO ZERO FIVE
2	True course	050 TRUE	ZERO FIVE ZERO TRUE
3	Magnetic bearing	360	THREE SIX ZERO
4	Magnetic heading	100	HEADING ONE ZERO ZERO
5	Wind direction	220	WIND TWO TWO ZERO

Example: Approach Assigns a Magnetic Heading Approach: "November One Two Three Alpha Bravo, fly heading one zero zero." Pilot: "Fly heading one zero zero, November One Two Three Alpha Bravo."

Example: Pilot Reports a True Course Pilot: "November One Two Three Alpha Bravo, on course zero five zero true."

No readback is required from Approach unless the controller needs the value repeated for clarity.

Note: HEADING and WIND are spoken as prefix words before their three digits; COURSE and BEARING are not, and TRUE is spoken only after a course, bearing, or heading value that is not magnetic, as shown in Table 17-1.

4.18 Speed and Mach Number Phraseology

This paragraph establishes how pilots and controllers pronounce airspeed and Mach number values in radio transmissions.

18.a. When transmitting an airspeed value, each pilot and each controller WILL state the separate digits of the speed followed by the word "KNOTS," except that a controller MAY omit "KNOTS" when issuing a speed adjustment instruction under paragraph 4.39, Speed Adjustments.

Example: Airspeed Statement

Value	Spoken Form
250 knots	TWO FIVE ZERO KNOTS
190 knots	ONE NINER ZERO KNOTS

Example: Speed Adjustment Instruction (KNOTS Omitted) Approach: "Viper One One, reduce speed to two five zero." Pilot: "Reduce speed to two five zero, Viper One One."

Note: The omission of "KNOTS" applies only to a controller's speed adjustment instruction. Every other spoken airspeed value, by either a pilot or a controller, includes "KNOTS."

18.b. When transmitting a Mach number value, each pilot and each controller WILL state the separate digits of the Mach number preceded by the word "MACH."

Example: Mach Number Statement

Value	Spoken Form
Mach 1.5	MACH ONE POINT FIVE
Mach 0.64	MACH POINT SIX FOUR
Mach 0.7	MACH POINT SEVEN

Example: Mach Number Instruction and Readback Center: "Viper One One, maintain Mach point seven." Pilot: "Maintain Mach point seven, Viper One One."

4.19 Time

This paragraph establishes how each pilot and controller states time, in UTC or in local time, during radio and telephone communications, and how a controller or FSS specialist provides a time check.

19.a. When stating a time during a radio or telephone communication, each pilot or controller must identify a local time as local, either by the word "local" or by naming the applicable time zone. UTC is the time reference for all facility and cockpit operations. Each pilot or controller may use the brevity term ZULU in place of UTC.

Example: Stating Time Any Station: "...fuel on board one plus three zero, estimating one three three zero Zulu." Any Station: "...return to base at zero seven three zero Eastern."

19.b. Each pilot or controller will convert a standard local time to UTC by adding the number of hours listed in Table 19-1 for the applicable time zone.

Table 19-1. Standard Time to UTC Conversion

Time Zone	Hours Added to Convert to UTC
Eastern Standard Time (EST)	5
Central Standard Time (CST)	6
Mountain Standard Time (MST)	7
Pacific Standard Time (PST)	8
Alaska Standard Time (AKST)	9
Hawaii Standard Time (HST)	10

Legend: UTC = Coordinated Universal Time.

19.c. When stating a local daylight or standard time instead of UTC, each pilot or controller may use the 24-hour clock system, in which the first two figures state the hour and the last two figures state the minutes. Each figure is pronounced individually.

Example: 24-Hour Clock Time For 0000: "Zero zero zero zero." For 0920: "Zero niner two zero."

19.d. Each pilot or controller may state a time using only the minutes, in two figures, during a radiotelephone communication when doing so is unlikely to cause misunderstanding.

19.e. When a controller or FSS specialist provides a time check, the controller or specialist will state the current time to the nearest quarter minute. (1) If the fraction past the quarter minute is less than 8 seconds, the controller or specialist will state the preceding quarter minute. (2) If the fraction past the quarter minute is 8 seconds or more, the controller or specialist will state the succeeding quarter minute.

Example: Time Check Pilot: "Reach Three One, request time check." Controller/FSS Specialist (for 0929:05): "Time, zero niner two niner." Controller/FSS Specialist (for 0929:10): "Time, zero niner two niner and one-quarter."

Note: The threshold in subparagraph d for stating minutes only is not a numeric standard; the transmitting pilot or controller judges, call by call, whether the abbreviated form risks misunderstanding.

C. Airport Operations (Paragraphs 4.20–4.28)

4.20 Airports with an Operating Control Tower

This paragraph establishes two-way radio contact, clearance, and traffic pattern rules between Tower and each pilot, and the extent to which Tower may use radar to assist that traffic.

20.a. Two-Way Radio Contact.

20.a.(1) When operating within the Class B, Class C, or Class D surface area of an airport with an operating control tower, each pilot must maintain two-way radio contact with Tower, unless Tower authorizes otherwise.

20.a.(2) Prior to entering that surface area, each pilot should call Tower about 15 NM from the airport.

20.a.(3) Once each pilot has complied with subparagraph a.(1), each pilot should remain on Tower's frequency until leaving the surface area, absent a valid reason to change sooner.

20.a.(4) Once clear of the surface area, each pilot may leave Tower's frequency without requesting permission.

Note: Not every tower's surface area is Class D; where it is not, controlled airspace above the airport typically begins at 700 ft AGL or 1,200 ft AGL.

Example: Initial Contact With Tower Pilot: "Springfield Tower, Cessna Three Four Bravo, one five miles southwest, two thousand five hundred, landing, information Bravo." Tower: "Cessna Three Four Bravo, Springfield Tower, enter left downwind, runway two seven." Required response: The pilot acknowledges Tower's instruction by call sign.

20.b. Tower Clearances and Traffic Pattern Direction.

20.b.(1) When operating within the surface area or on the airport movement area, Tower will issue each pilot the clearance or instruction for the aircraft's flight path or taxi route.

20.b.(2) Unless otherwise authorized or directed by Tower, each pilot of a fixed-wing aircraft approaching to land must circle the airport to the left.

20.b.(3) When operating in the traffic pattern, each helicopter pilot must avoid the flow of fixed-wing traffic rather than fly the pattern described in subparagraph b.(2).

20.b.(4) Prior to landing at an airport with an operating control tower, each pilot must receive an appropriate clearance from Tower.

20.c. Traffic Pattern Legs.

Table 20-1. Traffic Pattern Legs

Leg	Definition
Departure	Straight ahead on the extended runway centerline after takeoff, to at least 1/2 NM beyond the runway's departure end and within 300 ft of traffic pattern altitude.
Upwind	Extension of departure; used by Tower for separation, spacing, or sequencing.
Crosswind	At right angles to the landing runway, off its takeoff end.
Downwind	Parallel to the landing runway, opposite the direction of landing.
Base	At right angles to the landing runway, off its approach end, to the extended runway centerline.
Final	On the extended runway centerline, from the base leg to the runway, in the direction of landing.

Note: These definitions describe each leg's shape only; Tower assigns pattern altitude, entry, and runway separately under subparagraph b.(1).

20.d. Tower Radar Use.

20.d.(1) When Tower requires an aircraft's position relative to other traffic, Tower may instruct the pilot to squawk IDENT.

20.d.(2) Once Tower has issued the instructions under subparagraph d.(1), Tower may discontinue radar monitoring.

20.d.(3) When Tower's workload permits (discretion), Tower may provide radar traffic advisories, subject to its primary runway-separation duties.

20.d.(4) When assisting a pilot flying VFR toward the traffic pattern, Tower may issue a suggested heading or direction. This instruction is advisory only, not a radar vector; each pilot may accept or decline it and retains sole responsibility to see and avoid other traffic.

Example: Suggested Heading for Radar Identification Tower: "Cessna Three Four Bravo, proceed southwestbound, enter a right downwind, runway three zero," or "suggested heading two two zero, for radar identification." Required response: The pilot complies, or advises Tower UNABLE and continues own navigation.

20.d.(5) When a pilot is on an extended downwind during Class B, Class C, or Class D operations, Tower may advise the pilot when to turn base.

Note: Tower need not maintain constant radar identification, because continuous monitoring could compromise Tower's visual scan of the airport. Each pilot must not assume radar contact, once established, continues throughout the flight.

20.e. Radar-Equipped Tower Services.

20.e.(1) Based solely on operational need, the FAA may authorize Tower to separate aircraft by radar in specific situations, or to function as a limited radar approach control position; this authorization is not published.

20.e.(2) At any airport with an operating control tower, each pilot must not assume that constant radar monitoring or complete ATC radar services are being provided, because radar-equipped and non-radar towers are not distinguishable to the pilot.

4.21 Traffic Patterns

This paragraph establishes traffic pattern altitudes by aircraft category, standard turn direction, right-traffic identification and assignment, and straight-in approach coordination, for each pilot operating to or from an airport's traffic pattern, whether towered or non-towered.

21.a. Unless the Chart Supplement publishes a different pattern altitude for the airport, or the cloud clearance minima in 14 CFR Section 91.155 require otherwise, in which case the published or required altitude governs instead, each pilot SHOULD enter the traffic pattern at the altitude listed below for the aircraft's category.

21.a.(1) Propeller-driven aircraft: 1,000 ft AGL.

21.a.(2) Large and turbine-powered aircraft: not less than 1,500 ft AGL, or 500 ft above the established pattern altitude.

21.a.(3) Helicopters: 500 ft AGL, flown closer to the runway than the fixed-wing pattern.

When airspeed requires it, or for practice power-off landings (autorotation), and when local procedures authorize the practice (briefed every mission), a helicopter pilot MAY fly the pattern on the side of the runway opposite fixed-wing traffic. When landing away from the runway, a helicopter pilot MUST avoid the flow of fixed-wing traffic.

21.b. Each pilot MAY vary the size of the traffic pattern to match the aircraft's performance characteristics. Each pilot of an en route aircraft SHOULD remain alert for aircraft operating in traffic patterns and SHOULD avoid entering those areas when operationally practicable (discretion).

21.c. Unless the airport's chart designates right traffic under subparagraph d, or Tower assigns right traffic by radio, in which case each pilot turns right instead, each pilot MUST turn left at each turn in the traffic pattern; this requirement does not apply to a helicopter flying the pattern described in subparagraph a.(3).

21.d. A Right Pattern (RP) notation, followed by one or more runway numbers in the airport data block on a Sectional, IFR Enroute Low, or VFR Terminal Area Chart, designates those runways for right-hand traffic (for example, "RP 9, 18, 22R"). At an airport with a full-time control tower, Tower will assign the traffic pattern direction to each pilot by radio instruction rather than by chart symbol.

Example: Right Traffic Assignment Tower: "November Four Alpha Bravo, runway nine, make right traffic, cleared for takeoff." Pilot: "Right traffic, runway nine, cleared for takeoff, November Four Alpha Bravo."

Example: Traffic Pattern Position Report (Non-Towered Airport) Pilot, on the CTAF: "Example traffic, Skyhawk Four Alpha Bravo, entering left downwind, runway two seven, Example." No response is required; other pilots in the pattern use the report to maintain visual separation.

Note: An RP notation indicates that special conditions apply to the runway; each pilot SHOULD consult the Chart Supplement for those conditions before using it. Right traffic patterns are not depicted on charts for airports with a full-time control tower, because Tower assigns pattern direction by radio.

Reference: Advisory Circular (AC) 90-66, Non-Towered Airport Flight Operations.

21.e. Straight-In Approaches. Each pilot MAY fly a straight-in approach instead of the standard traffic pattern. When flying a straight-in approach, the pilot SHOULD NOT disrupt the flow of arriving and departing traffic in the traffic pattern. Each pilot flying the traffic pattern SHOULD remain alert for aircraft executing straight-in approaches.

Example: Straight-In Approach Request (Towered Airport) Pilot: "Example Tower, Skyhawk Four Alpha Bravo, ten miles south, request straight-in, runway one eight." Tower: "Skyhawk Four Alpha Bravo, Example Tower, report three mile final, runway one eight." Pilot: "Report three mile final, runway one eight, Skyhawk Four Alpha Bravo."

Note: The self-announce phraseology for a straight-in approach at an airport without an operating control tower is established in paragraph 4.4.g(4), Self-Announce Procedures.

21.f. Before entering the traffic pattern, each pilot SHOULD determine the headwind, crosswind, and tailwind components for the runway in use, using a wind component chart such as one published by the aircraft manufacturer.

4.22 Intersection Takeoffs

This paragraph establishes procedures for departing from a runway intersection, including preflight distance planning, controller-issued distance measurements, and minimum intervals between successive intersection departures.

22.a. When Ground or Tower, whichever is currently working the aircraft, offers or approves a takeoff from a runway intersection, the pilot SHOULD state a preference for a different intersection, for the full length of the runway, or for the measured distance from the intersection to the runway end.

Example: Requesting Full-Length Departure Pilot: "Apache Three Seven Two Two Papa, request full length, runway two three right." Ground: "Apache Three Seven Two Two Papa, runway two three right, full length approved, taxi via Alpha."

22.b. During preflight planning, the pilot MUST determine that the aircraft's minimum required takeoff distance fits within the runway length and the declared distances remaining from the intersection the pilot intends to use. The pilot MUST NOT accept an intersection departure for which the remaining runway length or remaining declared distances are insufficient.

22.c. When a pilot requests it, or in every case for a military aircraft, Ground or Tower, whichever is currently working the aircraft, WILL state the measured distance from the intersection to the runway end, rounded down to the nearest 50 ft. This requirement does not apply where use of the intersection is covered by a separate published directive, and neither facility will state a distance from the intersection to a declared-distance endpoint.

22.d. Each pilot WILL taxi to, but not onto, the end of the assigned runway, unless Ground has granted prior approval for an intersection departure, in which case the pilot taxies to the approved intersection instead.

22.e. When calling Tower for takeoff from a runway intersection, the pilot SHOULD state the pilot's position on the airport in the same transmission.

Example: Position Report at an Intersection Pilot: "Cleveland Tower, Apache Three Seven Two Two Papa, at the intersection of taxiway Oscar and runway two three right, ready for departure."

22.f. When a small aircraft (12,500 lb or less) is departing from an intersection on a runway, same or opposite direction, behind a large nonheavy aircraft other than a Boeing 757, or behind another small aircraft over 12,500 lb, Tower MUST hold the succeeding aircraft's takeoff roll for at least 3 minutes after the preceding aircraft's takeoff. The succeeding pilot MAY request a waiver of this interval after weighing the wake turbulence hazard. Requesting the waiver constitutes the pilot's acceptance of responsibility for wake turbulence separation, and Tower MAY then issue takeoff clearance if other traffic permits.

Example: Requesting a Waiver to the 3-Minute Interval Pilot: "Request waiver to 3-minute interval." Tower: "Apache Three Seven Two Two Papa, waiver approved, wind two three zero at eight, runway two three right, cleared for takeoff."

22.g. The 3-minute interval in subparagraph f does not apply when the intersection lies 500 ft or less from the preceding aircraft's departure point and both aircraft depart in the same direction. Otherwise the interval in subparagraph f applies. Tower MAY instruct the succeeding small aircraft to alter course after takeoff to avoid the preceding aircraft's flight path.

22.h. Regardless of any waiver available under subparagraph f, Tower MUST apply a 4-minute interval to any small, large, or heavy aircraft departing behind a super aircraft. Tower MUST apply a 3-minute interval to any aircraft departing behind a heavy aircraft, and to a small aircraft departing behind a Boeing 757, with no waiver available for either interval.

Note: The 3-minute and 4-minute intervals in subparagraphs f and h are wake turbulence separation minimums, distinct from the wake-turbulence responsibility a pilot accepts by taking a visual separation instruction under paragraph 4.41.d, Wake Turbulence and Super-Category Restriction. A pilot's waiver under subparagraph f transfers responsibility for wake turbulence avoidance to the succeeding pilot but does not relieve Tower of separation from other traffic.

4.23 Low Approach

This paragraph establishes how a pilot flies a low approach (also called a low pass) and how the pilot coordinates that maneuver with Tower, an FSS, or other traffic advisory sources.

23.a. Definition. A low approach is a go-around maneuver flown after an approach, in place of landing or a touch-and-go, typically to expedite a repeated operation such as a series of practice instrument approaches.

23.b. Flight Path. Unless ATC has authorized a different flight path, the pilot flying a low approach SHOULD continue straight ahead, with no turn and no climb, until the pilot has completed a visual check for other aircraft in the area.

23.c. Tower Approval. Before starting the final approach, a pilot who intends to fly a low approach within a Class B, Class C, or Class D surface area SHOULD contact Tower to request approval.

Example: Low Approach Request to Tower

Speaker	Transmission
Pilot	"Tower, November One Two Three Alpha Bravo, request low approach, runway two seven."
Tower	"November One Two Three Alpha Bravo, low approach approved, runway two seven, no delay, traffic a Cessna on a two mile final."

Legend: Tower's response may instead deny the request or issue instructions; the pilot complies with whatever Tower authorizes in place of the default straight-ahead flight path in subparagraph b above.

23.d. Traffic Advisory. Prior to leaving the final approach fix inbound on a nonprecision approach, or the outer marker (or the fix used in lieu of the outer marker) inbound on a precision approach, a pilot who intends to fly a low approach at an airport not within a Class B, Class C, or Class D surface area SHOULD advise the FSS, advise the UNICOM station, or make a broadcast, whichever is available at that airport.

Example: Low Approach Advisory Broadcast

Speaker	Transmission
Pilot	"Podunk traffic, November One Two Three Alpha Bravo, five mile final, runway two seven, low approach, Podunk."

Note: Which of FSS, UNICOM, or a self-announce broadcast is available, and on which frequency, depends on the individual airport. Traffic advisory practices at airports without an operating control tower are established in paragraph 4.4, Traffic Advisory Practices at Airports Without an Operating Control Tower.

4.24 ATC Frequency Communications on the Airport

This paragraph establishes procedures for initial contact on Ground, Clearance Delivery, and Tower frequencies; for interpreting abbreviated frequency callouts; and for frequency changes, including changes issued to single-piloted helicopters near the ground.

24.a. Before starting engines, the pilot should contact Ground or Clearance Delivery to receive engine start time, taxi instructions, and/or clearance information. Unless Tower advises otherwise, the pilot will remain on that frequency through taxi and run-up, then will switch to Tower when ready to request takeoff clearance.

Note: Pilots are encouraged to monitor Tower's frequency as soon as practical, consistent with other ATC requirements. See paragraph 4.5, Automatic Terminal Information Service (ATIS), for ATIS monitoring procedures.

Example: Ground Contact Before Taxi Pilot: "Ground, Falcon Four One, ramp, information Bravo, ready to taxi." Ground: "Falcon Four One, taxi runway two seven via Alpha, hold short runway one eight." Pilot (after taxi and run-up): "Tower, Falcon Four One, ready for departure, runway two seven." Tower: "Falcon Four One, runway two seven, cleared for takeoff."

24.b. Once a turbine-powered aircraft reaches the runway or the warm-up block, Tower will consider that aircraft ready for takeoff unless the pilot advises Tower otherwise.

24.c. After landing, the pilot should not switch from Tower's frequency to Ground until Tower directs the change. Each airport will normally have one Ground frequency; an airport with higher traffic volume may be assigned a second Ground frequency, a separate Clearance Delivery frequency, or both.

Note: Ground frequencies, typically 121.6 to 121.9 MHz, carry taxi instructions, clearances, and airport vehicle contacts separately from Tower's local control frequency, keeping local control clear for arriving and departing traffic.

24.d. When transmitting a frequency in the 121 MHz band, Ground or Tower may omit the digits preceding the decimal point if the controller believes the pilot already knows which frequency is in use. If the pilot has any doubt which frequency is meant, the pilot should promptly request that the controller state the full frequency.

Example: Abbreviated Frequency Callout Ground: "Falcon Four One, contact Ground point seven." Pilot (no doubt as to frequency): "Ground point seven, Falcon Four One." (Tunes 121.7 MHz.) Pilot (doubt as to frequency): "Falcon Four One, request full frequency."

24.e. For a helicopter known to be single-piloted that is hovering, air taxiing, or operating near the ground, ATC will normally avoid issuing a radio frequency change during that phase. The pilot should advise ATC of single-pilot status when doing so will reduce delay to essential ATC communications. When a frequency change to such a helicopter is necessary, ATC will relay instructions through the frequency currently monitored until the change is completed, where relay is technically possible. The pilot must promptly advise ATC if unable to comply with a frequency change instruction. The pilot should advise ATC when landing is required to accomplish a frequency change, except that no advisory is required when the landing clearly will not affect other traffic, for example landing on a taxiway or in a helicopter operating area.

Example: Single-Pilot Helicopter Unable to Change Frequency Approach: "Rescue One Seven, contact Departure, one three four point five." Pilot (hovering, single-piloted): "Rescue One Seven, UNABLE frequency change, hovering." Approach: "Rescue One Seven, ROGER, standing by, will relay through this frequency."

4.25 VFR Operations in Terminal Areas

This paragraph establishes standards of pilot judgment for operations conducted under VFR in and near terminal-area controlled airspace, including retention of an IFR clearance in reduced visibility and the added visibility margin required for simulated instrument flight training.

25.a. General Restraint. Throughout VFR operations conducted in or near terminal-area controlled airspace, each pilot SHOULD exercise restraint beyond the published visibility and cloud-clearance minimums for the applicable airspace class, treating those published minimums as floors rather than as targets.

25.b. Approach Area. When operating under VFR in a Class B, Class C, Class D, or Class E surface area at the minimum reported visibility for that class (3 SM or 4 SM, according to the applicable class), the pilot SHOULD remain clear of the approach area to the active runway. Outside of this visibility condition, no additional restraint beyond standard visibility and cloud-clearance compliance is required.

Note: VFR flight within the approach area at this visibility is not a violation of any regulation; this is a recommended practice, not a mandatory restriction.

25.c. Reduced Visibility. When precipitation is reducing forward visibility while the pilot is operating on an IFR flight plan toward a terminal area, the pilot SHOULD continue the IFR operation, rather than canceling IFR to proceed VFR, until reasonably close to the destination (discretion; no fixed distance is specified). Outside of precipitation-reduced visibility, the pilot MAY cancel IFR under standard cancellation practice at the pilot's discretion.

Example: Canceling IFR Near the Destination Pilot: "Approach, November One Two Three Alpha Bravo, one two miles west, field in sight, cancel IFR." Approach: "November One Two Three Alpha Bravo, IFR cancellation received, radar service terminated, squawk VFR, frequency change approved."

25.d. Simulated Instrument Flight.

25.d.(1) When conducting a simulated instrument flight under a safety pilot, the pilot flying SHOULD select weather with visibility beyond the minimum required for the flight, to compensate for the safety pilot's restricted visual scan and the pilot flying's reduced outside scan (discretion; no fixed margin is specified).

25.d.(2) When the planned route lies in or near a busy airway or close to an airport, the pilot flying SHOULD increase this margin further (discretion; no fixed margin is specified).

Note: The safety pilot and the pilot flying are distinct roles for this rule; the margin in (1) and (2) protects against the safety pilot's restricted field of view and the pilot flying's attention being concentrated on instruments rather than outside scan.

4.26 Taxi Clearances, Instructions, and Ground Communications

This paragraph establishes the clearance, readback, and phraseology requirements governing aircraft and vehicle movement on the airport surface, and the radio exchanges between the pilot and Ground, Clearance Delivery, and Tower during ATC hours.

26.a. Movement Area and Runway Clearance Authority.

26.a.(1) Prior to moving an aircraft or vehicle onto the movement area while Tower is in operation, the pilot must obtain approval from Tower.

26.a.(2) Prior to taxiing on a runway, taking off, or landing while Tower is in operation, the pilot must obtain clearance from Tower.

26.a.(3) Prior to crossing any runway, the pilot must obtain an explicit clearance, and Tower will issue an explicit clearance for each runway crossing.

26.a.(4) Tower and Ground must not use the word CLEARED in conjunction with an authorization to taxi, to preclude confusing a taxi authorization with a runway, takeoff, or landing clearance.

26.b. Content of Taxi Instructions.

26.b.(1) When assigning a departure runway, Tower will state the runway, issue the taxi route, and state any hold-short instruction or runway-crossing clearance the route requires; this taxi instruction does not by itself authorize the pilot to enter or cross the assigned departure runway at any point.

26.b.(2) When taxiing a pilot to a point other than the assigned departure runway, Ground will state the destination point, issue the taxi route, and state any hold-short instruction or runway-crossing clearance the route requires.

26.b.(3) When a pilot is expected to hold short of a runway approach or departure hold area or an Instrument Landing System (ILS) holding position, Tower will issue explicit instructions to that effect.

26.c. Readback of Taxi and Hold-Short Instructions.

26.c.(1) On receiving taxi instructions, the pilot must read back the runway assignment, any clearance to enter a specific runway, and any instruction to HOLD SHORT of a runway or to LINE UP AND WAIT.

26.c.(2) Whenever Tower issues a runway hold-short instruction, Tower must obtain a readback from the pilot; if the readback is not received, Tower must request it.

26.d. Initial Taxi Request. When calling Ground for taxi instructions prior to departure, the pilot must state the aircraft identification, the aircraft's position on the airport, whether the flight is VFR or IFR, and the point of first intended landing.

Example: Initial Taxi Request Pilot: "Washington Ground, Beechcraft One Three One Five Niner at hangar eight, ready to taxi, IFR to Chicago." Ground: "Beechcraft One Three One Five Niner, Washington Ground, runway two seven, taxi via taxiways Charlie and Delta, HOLD SHORT of runway three three left." Pilot: "Beechcraft One Three One Five Niner, runway two seven, HOLD SHORT of runway three three left."

26.e. Acknowledgment of Clearances.

26.e.(1) On receiving a runway crossing, hold-short, or takeoff clearance the pilot understands, the pilot should acknowledge the clearance.

26.e.(2) When the pilot does not understand a clearance or instruction, the pilot must query Tower until the clearance is understood.

26.f. Relay of Center Clearances.

26.f.(1) Ground will relay a Center clearance to the pilot.

26.f.(2) At locations with a clearance delivery frequency, Ground may instead direct the pilot to contact Clearance Delivery for relay of the clearance.

Note: Clearance Delivery exercises no surveillance or control over the movement of traffic; a pilot working Clearance Delivery must not expect separation or taxi service from that position.

Example: Receipt of Center Clearance Ground: "Beechcraft One Three One Five Niner, cleared to the Chicago Midway Airport via Victor Eight, maintain eight thousand." Pilot: "Beechcraft One Three One Five Niner, cleared to the Chicago Midway Airport via Victor Eight, maintain eight thousand."

26.g. Taxi Request After Landing. When calling Ground after landing, the pilot must state the aircraft identification, the runway and point at which the runway was vacated, and the requested taxi destination.

Example: Taxi Request After Landing Pilot: "Dulles Ground, Beechcraft One Four Two Six One clearing runway one right at taxiway Echo Three, request taxi to Page." Ground: "Beechcraft One Four Two Six One, Dulles Ground, taxi to Page via taxiways Echo Three, Echo One, and Echo Niner."

26.h. Progressive Taxi Instructions.

26.h.(1) When unfamiliar with the airport or uncertain of the taxi route, the pilot may request progressive, step-by-step taxi instructions.

26.h.(2) Ground or Tower may also issue progressive taxi instructions on its own initiative when traffic or field conditions, for example construction or a closed taxiway, warrant it.

26.i. Single-Pilot Frequency Discipline.

26.i.(1) After being cleared onto the active runway for departure, a pilot operating without additional crew should monitor only the assigned ATC frequency until clear of the Class B, Class C, or Class D surface area.

26.i.(2) After receiving a landing clearance, that pilot should apply the same restriction until the landing and taxi are complete.

26.i.(3) Each pilot should continuously scan for other aircraft, ground vehicles, and other objects throughout ground operations.

26.j. Clearance by Visual Light Signal. At a Tower where two-way radio communication is not required or cannot be established, the pilot must obtain clearance by visual light signal prior to taxiing onto a runway and prior to takeoff and landing.

26.k. Jet Blast, Prop Wash, and Rotor Wash. During ground operations, each pilot should account for the effects of jet blast, propeller wash, and rotor wash on other aircraft, vehicles, and maintenance equipment.

4.27 Exiting the Runway After Landing

This paragraph establishes the procedures each pilot follows to clear the landing runway after touchdown, and the corresponding responsibilities of Tower and Ground.

27.a. After landing and reaching taxi speed, each pilot will exit the runway without delay at the first available taxiway, or at the taxiway Tower specifies.

27.a.(1) Unless authorized by Tower, each pilot must not exit onto another runway.

27.a.(2) At an airport with an operating control tower, before stopping or reversing course on the runway, each pilot should obtain Tower's approval.

Example: Tower-Directed Runway Exit Tower: "November One Two Three Alpha Bravo, exit left at Bravo, contact Ground point niner." Pilot: "Left at Bravo, Ground point niner, November One Two Three Alpha Bravo."

27.b. Unless otherwise directed by Tower, each pilot will taxi clear of the landing runway after exiting.

Note: An aircraft is clear of the runway once every part of it has passed the runway edge and crossed the runway holding position markings, with no restriction to continued movement beyond those markings.

27.b.(1) In the absence of instructions from Tower, each pilot will continue taxiing beyond the holding position markings for the landing runway, even where doing so requires the aircraft to protrude into or cross another taxiway or ramp area.

27.b.(2) Once every part of the aircraft has crossed the holding position markings, each pilot must hold that position unless Tower has issued further instructions.

27.b.(3) When required to resolve a conflict with other traffic, Tower will issue instructions permitting the aircraft to enter another taxiway, runway, or ramp area.

Note: The runway-exit and clear-of-runway procedures in subparagraphs a and b are part of the landing clearance already issued; each pilot need not request, and Tower need not issue, a separate clearance to exit the runway or to taxi clear of it.

27.c. When advised by Tower, each pilot will change immediately to the Ground frequency and obtain a taxi clearance from Ground.

27.c.(1) Before advising a pilot to contact Ground, Tower will issue instructions resolving any conflict with other ground traffic.

27.c.(2) Under a Ground clearance to taxi to parking, each pilot must not enter or cross a runway (see paragraph 4.26.a(3), Movement Area and Runway Clearance Authority).

27.c.(3) When unfamiliar with the assigned taxi route, each pilot should request progressive taxi instructions from Ground, as established in paragraph 4.26.h, Progressive Taxi Instructions.

Example: Ground Handoff and Taxi Clearance Tower: "November One Two Three Alpha Bravo, contact Ground point niner." Pilot: "Ground point niner, November One Two Three Alpha Bravo." Ground: "November One Two Three Alpha Bravo, taxi to parking via Alpha, Bravo." Pilot: "Taxi to parking via Alpha, Bravo, November One Two Three Alpha Bravo."

4.28 Option Approach

This paragraph establishes OPTION APPROACH, a Tower clearance that lets the pilot defer, until short final or on the runway, which of several possible outcomes will end the approach.

28.a. Under an OPTION APPROACH clearance, the pilot may select, at the pilot's discretion, one of the following outcomes: a touch-and-go, a low approach, a missed approach, a stop-and-go, or a full stop landing.

28.b. Request Timing.

28.b.(1) When flying an instrument approach, the pilot should request OPTION APPROACH passing the final approach fix inbound.

28.b.(2) When flying a VFR traffic pattern, the pilot should request OPTION APPROACH upon entering downwind.

Example: Requesting the Option Pilot: "Springfield Tower, Cessna Three Alpha Bravo, request the option, runway two two." Tower: "Cessna Three Alpha Bravo, runway two two, cleared for the option."

28.c. At an airport with an operating control tower, Tower may approve a pilot's request for OPTION APPROACH. OPTION APPROACH must not be conducted at an airport without an operating control tower.

28.d. After Tower approves OPTION APPROACH, the pilot should notify Tower as soon as possible of any delay in clearing the runway following a stop-and-go or full stop landing.

Example: Reporting a Runway Delay Pilot: "Springfield Tower, Cessna Three Alpha Bravo, full stop, expect additional time clearing the runway." Tower: "Cessna Three Alpha Bravo, ROGER."

Note: OPTION APPROACH may be requested by any pilot; it is not limited to instructional or evaluation flights. It is frequently used for training because it does not disclose in advance which outcome the instructor or examiner has selected, letting the trainee or examinee react to whichever maneuver actually develops.

D. ATC Clearances and Aircraft Separation (Paragraphs 4.29–4.41)

4.29 Clearance

This paragraph establishes what an ATC clearance authorizes, each pilot's responsibility to request an amended clearance or report a deviation, and the division of separation responsibility between ATC and each pilot operating under IFR in VMC.

29.a. Authorization and Limits of a Clearance.

29.a.(1) When ATC issues a clearance, ATC authorizes the aircraft to proceed under the stated conditions within controlled airspace, based on known traffic and known physical airport conditions.

29.a.(2) Regardless of the clearance issued, each pilot must not treat that clearance as authorization to deviate from any rule, regulation, or minimum altitude, or to conduct an unsafe operation of the aircraft.

29.b. Pilot Authority and Requested Changes.

29.b.(1) The pilot-in-command retains final authority over the operation of the aircraft.

29.b.(2) When a clearance would require the pilot to deviate from a rule or regulation, or would, in the pilot's judgment, place the aircraft in jeopardy, the pilot must request an amended clearance from ATC.

29.b.(3) When the pilot prefers a different course of action than the one cleared (for example, a 360-degree turn for spacing, landing on a different runway, departing from a different intersection or from the threshold, or delaying an operation), the pilot will inform ATC of that preference; otherwise, the pilot complies with the clearance as issued.

29.b.(4) After informing ATC of a preferred different course of action, the pilot should cooperate with ATC to preclude disrupting traffic flow or creating conflicting patterns.

29.b.(5) On receipt of a clearance, frequency change, or advisory information, each pilot will acknowledge it using the aircraft's assigned call sign, per the readback practice established in paragraph 4.34, Clearance Readback and Acceptance.

Example: Requesting a Different Course of Action Pilot: "Reno Approach, November One Two Three Alpha Bravo, request three-six-zero for spacing prior to the approach." Approach: "November One Two Three Alpha Bravo, three-six-zero approved, report resuming the approach."

29.c. Deviation for Traffic Avoidance. When a pilot deviates from an ATC clearance in response to a Traffic Alert and Collision Avoidance System (TCAS) resolution advisory (RA), the pilot must notify ATC of that deviation as soon as possible after the deviation.

Example: TCAS RA Deviation Report Pilot: "Center, November One Two Three Alpha Bravo, TCAS RA, descending." Center: "November One Two Three Alpha Bravo, ROGER."

29.d. Separation Responsibility in Visual Conditions. During VMC, while operating under IFR, each pilot will remain responsible for avoiding other aircraft, per the visual scanning duty established in paragraph 4.41.f, Visual Scanning for Collision Avoidance.

Note: ATC clearances provide standard separation only between IFR flights; VFR flights may be operating in the same area without ATC's knowledge, so an IFR pilot's own vigilance in VMC is not relieved by the clearance.

4.30 Clearance Prefix

This paragraph establishes the prefix a relaying station uses when passing a pilot a clearance, control information, or a response to a request for information that originated with an ATC facility.

30.a. When an FSS relays to a pilot a clearance, control information, or a response to a request for information that originated with an ATC facility, the FSS WILL prefix the transmission with "ATC CLEARS," "ATC ADVISES," or "ATC REQUESTS," matching the prefix to the type of message being relayed: "ATC CLEARS" for a clearance, "ATC ADVISES" for control information, and "ATC REQUESTS" for a response to a pilot's request for information.

Example: Relayed ATC Traffic FSS (relaying a clearance): "November One Two Three Four Alpha, ATC CLEARS, cleared to Example Airport via direct, climb and maintain five thousand." Pilot: "ATC CLEARS, cleared to Example Airport via direct, climb and maintain five thousand, November One Two Three Four Alpha." FSS (relaying control information): "November One Two Three Four Alpha, ATC ADVISES, traffic is a flight of four, eastbound, one thousand feet below." Pilot: "ROGER, November One Two Three Four Alpha." FSS (relaying a response to the pilot's request): "November One Two Three Four Alpha, ATC REQUESTS your present altitude." Pilot: "November One Two Three Four Alpha, level five thousand."

Note: The prefix identifies the transmission as the ATC facility's own clearance, advisory, or request, not an instruction originating with the FSS. The pilot reads back a relayed clearance in full and complies with it as an ATC clearance, exactly as when receiving that clearance over a direct ATC frequency.

4.31 Clearance Items

This paragraph establishes the required elements of an ATC clearance and the pilot and controller responsibilities for each: clearance limit, departure procedure, route of flight, altitude data, and holding instructions.

31.a. Clearance Limit. The clearance limit is the fix, point, or airport to which an ATC clearance authorizes the flight.

31.a.(1) When the destination airport is the clearance limit, ATC WILL state the airport name followed by the word AIRPORT.

31.a.(2) When a navigational aid, intersection, or waypoint is the clearance limit and its type can be determined, ATC WILL include that type designation in the clearance.

31.a.(3) At facilities where established procedures provide for it, ATC MAY issue an abbreviated departure clearance authorizing flight only to a fix within or just outside the terminal area, together with the frequency on which the pilot WILL obtain the long-range clearance from Center.

31.b. Departure Procedure. When separation from other terminal-area traffic requires it, ATC WILL issue specific headings and/or altitude restrictions for the departure.

Note: At high-volume locations, the FAA publishes standardized Departure Procedures (DPs), consisting of Obstacle Departure Procedures (ODP) and Standard Instrument Departures (SID), rather than issuing separation instructions individually. See AIM Paragraph 5-2-9.

31.c. Route of Flight.

31.c.(1) Absent a traffic-related reason to do otherwise, ATC WILL clear the pilot via the route and altitude filed in the flight plan. When traffic conditions require a different route or altitude, or when the flight operates over a corridor with an established preferred route, ATC WILL assign the amended route or altitude instead.

Note: FSSs and flight plan processing facilities can provide preferred-route information during preflight planning.

31.c.(2) When the clearance requires the pilot to report over a fix identified by radio signal, ATC WILL include the data needed to identify that reporting point. If the pilot's aircraft cannot receive the signal(s) needed to identify the fix, the pilot MUST advise ATC immediately.

31.d. Altitude Data.

31.d.(1) After ATC assigns an altitude or flight level, the pilot WILL MAINTAIN it. When the pilot wants to climb or descend from the assigned altitude, the pilot SHOULD request that change before the time the pilot wants it to take effect.

31.d.(2) When the altitude ATC assigns differs from the altitude the pilot requested, ATC SHOULD advise the pilot when to expect the requested altitude, or advise the pilot to request it again from the next facility. If the pilot receives neither before leaving the current facility's frequency and still wants the different altitude, the pilot WILL re-request it from the next facility.

31.d.(3) When ATC issues a CRUISE clearance, the pilot MAY level off at any altitude within the block from the minimum IFR altitude up to and including the altitude ATC specifies, and MAY climb or descend within that block without further clearance. Once the pilot reports leaving an altitude within the block, the pilot MUST NOT return to that altitude without a new ATC clearance.

Note: See the Pilot/Controller Glossary term "Cruise" for the full definition of this clearance type.

Example: Cruise Clearance Center: "November One Two Three Alpha Bravo, cruise eight thousand." Pilot: "Cruise eight thousand, November One Two Three Alpha Bravo."

31.e. Holding Instructions.

31.e.(1) When ATC clears the pilot to a fix other than the destination airport and anticipates a delay, ATC WILL issue complete holding instructions (unless the holding pattern is charted), an Expect Further Clearance (EFC) time, and a best estimate of any additional en route or terminal delay.

31.e.(2) When a holding pattern is charted and ATC does not restate the full instructions, the pilot WILL hold as depicted on the chart, and ATC MAY abbreviate the clearance to direction and the phrase AS PUBLISHED. If the pilot requests complete holding instructions regardless of a charted pattern, ATC MUST provide them.

Note: A charted pattern flown under this subparagraph must be one published on a current FAA-approved U.S. government or commercially produced chart.

Example: Charted Holding, Abbreviated Instructions Center: "November One Two Three Alpha Bravo, hold east as published, expect further clearance one five three zero Zulu." Pilot: "Hold east as published, EFC one five three zero Zulu, November One Two Three Alpha Bravo."

31.e.(3) When no holding pattern is charted at the clearance limit and ATC has not issued holding instructions, the pilot SHOULD request instructions before reaching the fix to avoid flying an unintended pattern. If the pilot cannot obtain instructions because of a communications failure, the pilot MUST hold in a standard pattern on the course on which the aircraft approached the fix, and MUST attempt to obtain further clearance as soon as possible.

Note: Fix altitude protection remains in effect regardless of which holding pattern the pilot flies under this subparagraph.

31.e.(4) When the pilot is within 3 minutes of the clearance limit and has not received clearance beyond it, the pilot MUST begin reducing speed so as to cross the clearance limit initially at or below the maximum holding airspeed.

31.e.(5) ATC SHOULD issue the clearance beyond the fix at least 5 minutes before the aircraft's estimated arrival at the clearance limit.

31.e.(6) On arrival at, and on departure from, the clearance limit, the pilot MUST report the time and altitude to ATC.

Note: If two-way radio communications fail before the pilot receives further clearance, the pilot MUST comply with the lost-communications procedures of 14 CFR Section 91.185.

4.32 Amended Clearances

This paragraph establishes when a controller revises an aircraft's active IFR clearance to maintain separation, and the options available to a pilot who receives an amended clearance or wishes to fly a different one.

32.a. When continuing on the aircraft's existing clearance would cause separation from other IFR traffic to be lost, the controller WILL issue an amended clearance to the affected aircraft.

32.a.(1) The amended clearance MAY direct the aircraft to hold short of a point, or to change altitude, before reaching the point where the loss of separation would otherwise occur.

Example: Amended Clearance for Traffic Conflict Center: "November One Two Three Alpha Bravo, turn left heading two seven zero, descend and maintain flight level two two zero." Pilot: "Turn left heading two seven zero, descend and maintain flight level two two zero, November One Two Three Alpha Bravo."

Note: An amended clearance is often issued to prevent a conflict at a point well ahead of the aircraft's present position. A pilot who queries traffic after receiving an amendment may be told there is no traffic to report; this does not mean the amendment was issued in error.

32.b. When a pilot wants an explanation of an amended clearance at the time it is issued, the pilot MAY request one from the controller.

32.b.(1) The controller MAY decline to give an immediate explanation if doing so would take the controller from immediate control duties or add to frequency congestion.

32.b.(2) Otherwise, the controller WILL answer the request.

32.c. When a pilot wants an explanation of an amended clearance after the flight, the pilot MAY direct a letter or telephone call to the chief controller of the facility that issued the amendment.

32.d. When the pilot holds information indicating that another course of action is more practicable, or when aircraft equipment limitations or the pilot's operator or unit procedures prevent compliance with the clearance issued, the pilot MAY request a different clearance from the controller.

Example: Request for a Different Clearance Pilot: "Approach, November One Two Three Alpha Bravo is UNABLE flight level two two zero due to icing, request flight level three one zero." Approach: "November One Two Three Alpha Bravo, climb and maintain flight level three one zero."

4.33 Special VFR Clearances

This paragraph establishes special VFR (SVFR) clearance requirements for flight below VFR weather minimums within Class B, Class C, Class D, and Class E surface areas.

33.a. Before operating within a Class B, Class C, Class D, or Class E surface area when weather is below the ceiling or visibility required for VFR flight, the pilot MUST obtain an ATC clearance to operate under SVFR. The pilot MAY request the SVFR clearance to enter, leave, or operate within the surface area. The issuing facility MAY approve the request when traffic and IFR operations permit. Each SVFR flight MUST remain clear of clouds.

33.a.(1) The pilot MUST maintain at least 1 SM flight visibility while operating within the surface area under SVFR.

33.a.(2) The pilot MUST maintain at least 1 SM ground visibility for takeoff or landing under SVFR; when ground visibility is not reported for the airport, the pilot MUST maintain at least 1 SM flight visibility instead.

33.a.(3) The visibility minima in (1) and (2) do not apply to helicopters. A helicopter pilot MAY operate under SVFR with less than 1 SM visibility, provided the helicopter remains clear of clouds.

Example: Special VFR Clearance Request Pilot: "Springfield Tower, Cessna One Two Three Four Five, request special VFR to depart to the south, remaining clear of clouds." Tower: "Cessna One Two Three Four Five, cleared out of the Delta surface area special VFR, maintain at or below two thousand five hundred, clear of clouds." Pilot: "Cleared special VFR, at or below two thousand five hundred, clear of clouds, Cessna One Two Three Four Five."

33.b. When a control tower is located within the Class B, Class C, or Class D surface area, the pilot SHOULD direct the SVFR clearance request to that Tower. Within a Class E surface area, the pilot MAY request the SVFR clearance from the nearest Tower, FSS, or Center.

33.c. When requesting an SVFR clearance, the pilot MAY omit a complete flight plan but WILL state intentions in enough detail for the issuing facility to sequence the flight into traffic. The SVFR clearance MUST NOT specify an altitude. The issuing facility MAY require the pilot to fly at or below a stated altitude for traffic separation, and any altitude specified WILL remain at or above the minimum safe altitude. At a radar-equipped facility, the controller MAY vector the flight for control purposes or on pilot request.

Note: The pilot remains bound by the clear-of-clouds requirement in subparagraph a regardless of the altitude flown, and retains responsibility for obstacle and terrain clearance during an SVFR flight.

33.d. An SVFR clearance is valid only within the surface area for which it is issued. Once the aircraft exits that surface area, ATC WILL NOT provide separation to the flight.

33.e. Fixed-wing SVFR operations are prohibited at some Class B and Class C facilities, per local procedures. At such a facility, the pilot MUST NOT request a fixed-wing SVFR clearance, and the issuing facility WILL NOT issue one.

33.f. Within the surface area, the issuing facility WILL provide separation between SVFR flights and between SVFR flights and IFR flights.

33.g. Between sunset and sunrise, the pilot MUST NOT conduct fixed-wing SVFR operations unless the pilot holds an instrument rating and the aircraft is equipped for IFR flight.

33.h. When arriving at or departing an airport with an Automated Surface Observing System (ASOS) or AWOS within the surface area, the pilot SHOULD monitor the broadcast frequency. Before operating there, the pilot SHOULD advise the issuing facility of the one-minute weather and state intentions in the same transmission.

Example: One-Minute Weather Advisory Pilot: "Springfield Tower, Cessna One Two Three Four Five, has the one-minute weather, request special VFR, landing runway two seven."

Note: The one-minute weather is the most recent observation broadcast by the ASOS or AWOS, updated about every minute.

4.34 Clearance Readback and Acceptance

This paragraph establishes the pilot's obligations to record an ATC clearance, to read back its critical elements, and to decide whether to accept or refuse it. It is the authoritative statement of the general clearance-readback practice in this chapter; other paragraphs that describe a readback for a specific clearance type (for example, paragraph 4.26.c, taxi and hold-short instructions) state only what is additional to this paragraph.

34.a. On conducting an IFR operation, the pilot MUST make a written record of the ATC clearance.

Note: A clearance MAY include conditions, such as a specific departure route, that were not part of the filed flight plan. The pilot's written record reflects the clearance ATC actually issues, not the flight plan as filed.

34.b. When ATC issues a clearance or instruction that contains an altitude assignment, a vector, or a runway assignment, the pilot SHOULD read back that portion of the clearance or instruction.

Note: The readback of the numbers gives ATC a mutual check against communication errors that occur when a number is misheard or is incorrect.

34.b.(1) In every readback and acknowledgment, the pilot SHOULD include the aircraft's identification.

Note: Including the aircraft's identification becomes more important as frequency congestion increases and when aircraft with similar call signs share the same frequency.

Example: Readback with Aircraft Identification ATC: "United Twelve, climb and maintain flight level three three zero." Pilot: "Climbing to flight level three three zero, United Twelve." ATC: "November Five Charlie Tango, cleared to land, runway nine left." Pilot: "November Five Charlie Tango, ROGER, cleared to land runway nine left."

34.b.(2) The pilot SHOULD read back altitudes, altitude restrictions, and vectors in the same sequence ATC gives them in the clearance or instruction.

34.b.(3) The pilot SHOULD NOT read back an altitude contained in a charted procedure, such as a departure procedure or an instrument approach procedure, unless ATC specifically states that altitude in the clearance or instruction.

34.b.(4) In the initial readback of a taxi clearance, a departure clearance, or a landing clearance, the pilot SHOULD include the assigned runway, including its left, right, or center designator when one applies.

34.c. On receiving an ATC clearance, the pilot alone MUST decide whether to accept or refuse it.

4.35 VFR-on-Top and VFR Conditions Authorizations

This paragraph establishes the radio phraseology, required reports, and eligibility conditions for a pilot on an IFR flight plan who requests to operate VFR-on-top or in VFR conditions in lieu of an assigned altitude, and the conditions under which ATC may authorize such operations. The resulting separation responsibility, as distinct from this phraseology, is established in paragraph 4.38.b, Separation Responsibility.

35.a. When operating in VFR weather conditions on an IFR flight plan, the pilot may request VFR-on-top in lieu of an assigned altitude.

Note: A VFR-on-top authorization permits the pilot to select an altitude or flight level of the pilot's choice, subject to any ATC-specified restriction.

Example: Requesting VFR-on-Top Pilot: "Center, Speedy Two One, request VFR-on-top." ATC: "Speedy Two One, maintain VFR-on-top, report reaching."

35.b. When the pilot desires to climb through a cloud, haze, smoke, or other meteorological formation and then either cancel the IFR flight plan or operate VFR-on-top, the pilot may request a climb to VFR-on-top.

35.b.(1) In that authorization, ATC must include either a report of the cloud tops or a statement that no top report is available.

35.b.(2) In that same authorization, ATC must include a request for the pilot to report reaching VFR-on-top.

35.b.(3) In that same authorization, ATC may include a clearance limit, a route, and an alternate clearance to be flown if the pilot does not reach VFR-on-top by a specified altitude.

Example: Climb to VFR-on-Top Pilot: "Approach, Reach Three Three, request climb to VFR-on-top." ATC: "Reach Three Three, tops reported at eight thousand five hundred, climb to VFR-on-top, if not on top by one zero thousand, maintain one zero thousand and advise, report reaching VFR-on-top." Pilot (on reaching VFR-on-top): "Reach Three Three, VFR-on-top, level niner thousand five hundred."

35.c. When operating in VFR conditions on an IFR flight plan, the pilot may request to climb or descend in VFR conditions.

Example: Requesting a Climb in VFR Conditions Pilot: "Departure, Viper Four, request to climb in VFR conditions to one two thousand." ATC: "Viper Four, climb and maintain VFR conditions, report reaching one two thousand or VFR-on-top."

35.d. Unless the pilot requests the VFR operation, or authorizing VFR conditions will produce a noise abatement benefit where part of the IFR departure route does not conform to an FAA-approved noise abatement route or altitude, ATC must not authorize VFR-on-top or VFR conditions operations.

35.e. When operating in VFR conditions under an ATC authorization to maintain VFR-on-top or maintain VFR conditions, the pilot must:

35.e.(1) Fly the VFR altitude appropriate to the aircraft's course, as prescribed in 14 CFR Section 91.159.

35.e.(2) Comply with the VFR visibility and distance-from-cloud minima prescribed in 14 CFR Section 91.155, Basic VFR Weather Minimums.

35.e.(3) Comply with the instrument flight rules applicable to the flight, including minimum IFR altitudes, position reporting, radio communications, the course to be flown, and adherence to the ATC clearance.

Note: The pilot should advise ATC before any altitude change to ensure the exchange of accurate traffic information.

35.f. Under an ATC authorization to maintain VFR-on-top, the pilot may operate above, below, or between cloud layers, or in an area with no meteorological obscuration, without being restricted to operating only above the meteorological formation.

35.g. After receiving an authorization to operate VFR-on-top or in VFR conditions, the pilot must not treat that authorization as cancellation of the IFR flight plan.

35.h. When a pilot is operating VFR-on-top or in VFR conditions, ATC may provide that pilot with traffic information on other pertinent IFR and VFR aircraft.

35.i. When an aircraft is operating VFR-on-top or in VFR conditions within Class B airspace or a TRSA, ATC must provide separation in accordance with FAA Order JO 7110.65, Air Traffic Control.

35.j. In Class A airspace, ATC must not authorize VFR or VFR-on-top operations (established in AIM Paragraph 3-2-2, Class A Airspace).

4.36 VFR-to-IFR Transition Terrain Clearance

This paragraph establishes the pilot's responsibility for terrain and obstruction clearance when transitioning from VFR to IFR below the applicable minimum instrument altitude, and the required pilot report when that clearance cannot be maintained.

36.a. When a pilot departs under VFR intending to obtain an IFR clearance en route, or when changing conditions require the pilot to obtain one en route, the pilot MUST maintain awareness of the aircraft's position relative to surrounding terrain and obstructions.

36.b. When the pilot accepts an IFR clearance to an altitude below the applicable Minimum En Route Altitude (MEA), Minimum IFR Altitude (MIA), Minimum Vectoring Altitude (MVA), or Off-Route Obstruction Clearance Altitude (OROCA), the pilot MUST maintain the aircraft's own terrain and obstruction clearance until reaching the MEA, MIA, MVA, or OROCA, whichever applies.

Note: OROCA provides 1,000 ft AGL of terrain and obstruction clearance, or 2,000 ft AGL in designated mountainous areas. OROCA is not assessed for navigational aid (NAVAID) signal coverage, ATC surveillance, or communications coverage. It is published for general situational awareness, flight planning, and in-flight contingency use.

36.c. If the pilot is unable to maintain terrain or obstruction clearance while operating below the MEA, MIA, MVA, or OROCA, the pilot MUST advise the controller and state the pilot's intentions.

Example: Unable Terrain Clearance Pilot: "Center, Falcon 21, UNABLE terrain clearance at five thousand five hundred, request higher." Center: "Falcon 21, climb and maintain seven thousand."

Note: The controller's response is at the controller's discretion, based on the reported condition, traffic, and airspace, and is not a fixed phraseology set by this paragraph.

4.37 Adherence to ATC Clearances

This paragraph establishes the pilot's and the controller's obligations once an ATC clearance has been issued and accepted: compliance with its provisions, discretionary and default climb and descent execution, compliance with crossing restrictions, emergency deviation, and precedence between successive clearances. It applies to every clearance issued by Clearance Delivery, Ground, Tower, Departure, Approach, or Center to any aircraft, civil, military, or formation, operating under VFR or IFR. This paragraph does not cover the pilot's obligation to record and read back a clearance, established in paragraph 4.34, Clearance Readback and Acceptance, or ATC separation standards, established in paragraph 4.38, IFR Separation Standards.

37.a. Clearance Compliance. When the controller issues a clearance and the pilot-in-command accepts it, the pilot-in-command must not deviate from its provisions, under either VFR or IFR, unless the controller issues an amended clearance.

37.b. Assigned Headings and Turns. When the controller assigns a heading or requests a turn, the pilot will promptly initiate the turn, complete the turn, and maintain the new heading, unless the controller issues additional instructions before the turn is complete.

37.c. Pilot's Discretion.

37.c.(1) When a clearance's altitude instruction includes the phrase AT PILOT'S DISCRETION, the pilot may begin the climb or descent at a time of the pilot's choosing, conduct it at any rate, and level off temporarily at any intermediate altitude.

37.c.(2) Once the aircraft has vacated an altitude under (1), the pilot must not return to that altitude.

Example: Descent at Pilot's Discretion Center: "Falcon One Two, descend at pilot's discretion, maintain flight level two four zero." Falcon 12: "Descend at pilot's discretion, maintain flight level two four zero, Falcon One Two."

37.d. Climb and Descent Rates.

37.d.(1) When a clearance's altitude instruction does not include AT PILOT'S DISCRETION and imposes no climb or descent rate restriction, the pilot will initiate the climb or descent promptly on acknowledgment of the clearance, climb or descend at an optimum rate consistent with the aircraft's operating characteristics to within 1,000 feet of the assigned altitude, and then climb or descend at a rate between 500 and 1,500 feet per minute (fpm) until reaching the assigned altitude.

37.d.(2) If the pilot cannot maintain at least 500 fpm at any point during the climb or descent, the pilot will advise the controller.

37.d.(3) If the pilot must level off at an intermediate altitude during the climb or descent, the pilot will advise the controller, except when leveling off at 10,000 feet MSL during descent, or at 2,500 feet above airport elevation before entering a Class C or Class D surface area, to comply with an airspeed restriction; in those two cases, no advisory call is required.

Note: Leveling off at 10,000 feet MSL on descent, or at 2,500 feet above airport elevation before entering a Class C or Class D surface area, is commonplace and reflects the airspeed restriction applicable to that airspace; the controller does not need advance notice of it under (3).

Example: Standard-Rate Descent and Unable Advisory Approach: "Regional Eight Eight, descend and maintain five thousand." Regional 88: "Descend and maintain five thousand, Regional Eight Eight." Regional 88 (unable the minimum rate): "Approach, Regional Eight Eight is UNABLE five hundred feet per minute, expect three hundred until level." Approach: "Regional Eight Eight, ROGER."

37.e. Crossing Restrictions.

37.e.(1) When a descent clearance includes a crossing restriction phrased as CROSS (fix) AT or AT OR ABOVE/BELOW (altitude), the pilot may execute the descent by any profile that satisfies the crossing restriction.

37.e.(2) Within the portion of the flight to which a crossing restriction in (1) applies, the pilot must comply with the stated crossing altitude as a provision of the clearance.

Note: The discretion in (1) covers only the manner of descent; it is distinct from AT PILOT'S DISCRETION altitude language as defined in subparagraph c. A clearance carrying neither a crossing restriction nor AT PILOT'S DISCRETION language follows the default climb and descent rates in subparagraph d.

Example: Crossing Restriction Center: "Citation Three Juliet Kilo, cross Wilkes at or above one zero thousand, descend and maintain eight thousand." Citation 3JK: "Cross Wilkes at or above one zero thousand, descend and maintain eight thousand, Citation Three Juliet Kilo."

37.f. Emergency Deviation. When the pilot-in-command exercises emergency authority to deviate from a clearance, the pilot-in-command must notify the controller as soon as possible and obtain an amended clearance.

37.g. Precedence of Amended Clearances.

37.g.(1) When the controller issues an amended clearance, the amended clearance takes precedence over the clearance it replaces, and the controller will restate any previously issued altitude restriction that still applies.

37.g.(2) If the controller omits a previously issued altitude restriction from the amended clearance, that restriction, including a departure-procedure or Standard Terminal Arrival (STAR) altitude restriction, no longer applies.

Example: Amended Clearance Canceling a Prior Restriction Center (initial clearance): "Citation Three Juliet Kilo, cross Wilkes at or above one zero thousand, descend and maintain eight thousand." Center (later amendment): "Citation Three Juliet Kilo, radar vectors, descend and maintain eight thousand." Citation 3JK: "Radar vectors, descend and maintain eight thousand, Citation Three Juliet Kilo."

Note: The amendment above does not restate the Wilkes crossing restriction; under (2), that restriction no longer applies.

37.h. Afterburner Notification. When a turbojet aircraft equipped with afterburner engines intends to use afterburner during the climb to en route altitude, the pilot should advise the controller before takeoff.

Note: This call is a recommended practice, not a request for permission; the controller neither authorizes nor denies afterburner use in response to it.

Example: Afterburner Notification, Military Departure Falcon 12 (before takeoff): "Tower, Falcon One Two will use afterburner on departure." Tower: "Falcon One Two, ROGER."

37.i. Expedite Instructions. When the controller issues an EXPEDITE climb or descent instruction and later changes or restates the assigned altitude without repeating EXPEDITE, the later instruction cancels the EXPEDITE instruction, and the pilot will follow the default climb or descent rates in subparagraph d unless the controller states otherwise.

Example: Expedite Instruction Canceled by a Later Altitude Change Approach: "Skyhawk Two One Zero, expedite your climb through eight thousand for traffic, climb and maintain one two thousand." Skyhawk 210: "Expediting through eight thousand, climb and maintain one two thousand, Skyhawk Two One Zero." Approach (later): "Skyhawk Two One Zero, climb and maintain one six thousand." Skyhawk 210: "Climb and maintain one six thousand, Skyhawk Two One Zero."

Note: Because the later altitude instruction does not repeat EXPEDITE, the EXPEDITE instruction from the first call is canceled; standard climb rates under subparagraph d apply from that point.

4.38 IFR Separation Standards

This paragraph establishes how ATC separates aircraft operating on IFR flight plans, the point at which that separation responsibility passes to the pilot under a VFR-on-top or "maintain VFR conditions" clearance, and the minimum radar separation distances ATC applies between aircraft at the same altitude. Non-radar longitudinal separation and wake-turbulence separation are established elsewhere; visual separation is established in paragraph 4.41, Visual Separation.

38.a. Separation Methods. ATC will separate aircraft operating on IFR flight plans using one or more of the following methods: (1) vertical separation, by assigning different altitudes; (2) longitudinal separation, by maintaining an interval, expressed in time or distance, between aircraft on the same, converging, or crossing courses; and (3) lateral separation, by assigning different flight paths.

Note: These methods apply uniformly to civilian, military, and formation IFR traffic; ATC does not apply different separation criteria based on aircraft type or operator.

Example: Vertical Separation by Altitude Assignment Sender: ATC (here, Center), when assigning an altitude change to establish vertical separation from conflicting traffic under (1). Center: "Viper Two One, descend and maintain flight level two three zero, traffic one o'clock, one zero miles, opposite direction, flight level two four zero." Pilot: "Descend and maintain flight level two three zero, Viper Two One." Required response: the pilot reads back the assigned altitude, using the aircraft's call sign.

38.b. Separation Responsibility.

38.b.(1) When an aircraft is operating on an IFR flight plan, ATC will provide separation between that aircraft and all other IFR traffic, except for the portion of the flight, outside Class B airspace and outside a TRSA, conducted under a VFR-on-top or "maintain VFR conditions" clearance.

38.b.(2) During the excepted portion of the flight described in (1), the pilot must maintain the visual scanning and collision-avoidance vigilance established in paragraph 4.41.f, Visual Scanning for Collision Avoidance, and remains solely responsible for see-and-avoid separation from other traffic.

38.b.(3) Under the condition in (2), ATC may issue traffic advisories to the pilot; such an advisory does not transfer the responsibility stated in (2) back to ATC.

Note: The phraseology and required reports for requesting and receiving a VFR-on-top or VFR conditions clearance are established in paragraph 4.35, VFR-on-Top and VFR Conditions Authorizations. This subparagraph addresses only the resulting separation responsibility, not the clearance phraseology.

Example: Traffic Advisory During VFR-on-Top Sender: ATC (here, Approach), at ATC's discretion under (3), while the pilot is operating in the excepted portion of flight described in (1). Approach: "November One Two Three Alpha Bravo, traffic, ten o'clock, five miles, eastbound, altitude indicates six thousand five hundred, type unknown." Pilot: "Looking for traffic, November One Two Three Alpha Bravo." Required response: the pilot acknowledges the advisory using the aircraft's call sign; no maneuver is required by this call alone.

Note: Per (2), the pilot's see-and-avoid responsibility extends to traffic ATC does not report, not only to traffic ATC calls out.

38.c. Radar Separation Minima.

38.c.(1) When ATC uses radar to separate aircraft at the same altitude, ATC will apply the minima in Table 38-1.

Table 38-1. Radar Separation Minima by Distance from Antenna Site

Distance from radar antenna site	Minimum separation
Within 40 NM	3 NM
Beyond 40 NM	5 NM

Legend: NM = nautical miles.

38.c.(2) Under the condition in (1), ATC may increase or decrease the minima in Table 38-1 for a specific situation; no fixed threshold governs when this adjustment applies, and the determination is at ATC's discretion.

Note: Terminal-area separation standards may be increased above the minima in Table 38-1 when radar outages or other technical factors reduce radar performance.

Example: Lateral Separation by Radar Vector Sender: ATC (here, Approach), when vectoring an aircraft to establish lateral separation from conflicting traffic under (1). Approach: "Delta Two Two, turn left heading two seven zero for traffic, one o'clock, six miles, opposite direction, altitude indicates same." Pilot: "Left heading two seven zero, Delta Two Two." Required response: the pilot reads back the assigned heading, using the aircraft's call sign.

Note: The pilot does not hear the separation distance itself; ATC applies the minima in Table 38-1 internally and issues the pilot only the resulting instruction (here, a vector).

4.39 Speed Adjustments

This paragraph establishes how the controlling facility (Center; Approach; Departure; or, within a Class C or Class D surface area, Tower) issues, expresses, and terminates a speed adjustment to a radar-identified aircraft; the minimum speeds applied when assigning one; and each pilot's responsibility to comply with, or reject, an assigned speed. This paragraph does not establish separation minima, holding procedures, or missed-approach procedures; those are established elsewhere in this publication.

39.a. Issuance of Speed Adjustments.

39.a.(1) To achieve or maintain spacing between radar-identified aircraft, the controlling facility will issue a speed adjustment.

Example: Speed Adjustment for Spacing Center: "Jetstream Four Seven, reduce speed to two five zero knots." Pilot: "Reduce speed to two five zero knots, Jetstream Four Seven."

39.a.(2) When the controlling facility approves a pilot-requested deviation from a charted procedure, or vectors an aircraft off a charted procedure that carries a published speed restriction, and separation requires a speed adjustment, the controlling facility will assign one.

39.a.(3) On reaching the end of a STAR route while under a published speed restriction, the pilot must maintain the last published speed until the controlling facility does one of the following: deletes the restriction, assigns a new speed, issues a vector, assigns a direct routing, or issues an approach clearance.

Note: A STAR chart may separately publish a note identifying the speed to maintain when transitioning from a Mach-based speed to an indicated-airspeed (IAS)-based speed. Chart-published STAR procedures, including this kind of note, are established in paragraph 5.21, Standard Terminal Arrival (STAR) Procedures.

39.b. Speed Expression and Units.

39.b.(1) When issuing a speed adjustment, the controlling facility will express it in knots IAS, in increments of 5 or 10 knots.

39.b.(2) At or above Flight Level (FL) 240, for an aircraft equipped to display Mach number, the controlling facility may express the speed adjustment in Mach number instead, in increments of 0.01.

39.c. Speed Tolerance. When complying with a speed adjustment, the pilot should maintain the aircraft's speed within 10 knots IAS, or within 0.02 Mach number if the adjustment was issued in Mach, of the specified value.

39.d. Minimum Assigned Speeds.

39.d.(1) When assigning a speed adjustment, the controlling facility applies the minimum speed shown in Table 39-1 for the aircraft's phase of flight, engine type, and position relative to the airport or runway.

Table 39-1. Recommended Minimum Assigned Speeds

Category	Condition	Minimum Speed
Any aircraft	Between FL 280 and 10,000 ft MSL	250 kt IAS, or the equivalent Mach number
Arriving turbojet aircraft, below 10,000 ft MSL	Beyond 20 flying miles of the destination airport	210 kt IAS
Arriving turbojet aircraft, below 10,000 ft MSL	Within 20 flying miles of the destination airport	170 kt IAS
Arriving reciprocating-engine or turboprop aircraft	Within 20 flying miles of the runway threshold	150 kt IAS
Departing turbojet aircraft	N/A	230 kt IAS
Departing reciprocating-engine aircraft	N/A	150 kt IAS

Legend: FL = Flight Level. MSL = mean sea level. kt = knots. IAS = indicated airspeed.

Note: The source states these distance thresholds as "20 flying miles" and defines them by flying distance to the airport, runway, or destination rather than by a straight-line measurement. [VERIFY: confirm "flying miles" is read as nautical miles measured along the flight path before publishing this threshold to controllers.]

Table 39-2. Mach Number Equivalent to 250 Knots Calibrated Airspeed (CAS) (Standard Day)

Flight Level	Mach Number
FL 240	0.60
FL 250	0.61
FL 260	0.62
FL 270	0.64
FL 280	0.65
FL 290	0.66

Legend: FL = Flight Level. CAS = calibrated airspeed.

Note: The Table 39-2 values apply to a standard-day atmosphere and are subject to minor variation from that condition. Use Table 39-2 only where a Mach-based minimum speed applies under (1) above.

39.d.(2) When a speed below the Table 39-1 minimum will produce an operational advantage, the controlling facility may assign that lower speed instead.

39.e. Combined Speed and Descent Clearances.

39.e.(1) When the controlling facility combines a speed adjustment with a descent clearance in one transmission, the controlling facility will state the two instructions in the order it expects the pilot to execute them, separated by the word "then."

Example: Descend-Then-Reduce-Speed Clearance Approach: "Falcon Two Two, descend and maintain eight thousand, then reduce speed to two one zero knots." Pilot: "Descend and maintain eight thousand, then reduce speed to two one zero knots, Falcon Two Two."

Example: Reduce-Speed-Then-Descend Clearance Approach: "Falcon Two Two, reduce speed to two one zero knots, then descend and maintain eight thousand." Pilot: "Reduce speed to two one zero knots, then descend and maintain eight thousand, Falcon Two Two."

39.e.(2) If the pilot is uncertain of the order in which to execute a combined clearance issued under (1), the pilot should request clarification from the controlling facility before complying; otherwise, the pilot executes the clearance in the stated order.

Note: The maximum indicated airspeeds established in subparagraph i continue to apply below 10,000 feet MSL regardless of any speed adjustment issued under this subparagraph.

39.f. Terminating a Speed Adjustment. Each instruction in this subparagraph is a distinct phrase. On receiving any of them, the pilot must read back the phrase issued.

39.f.(1) When an ATC-assigned speed adjustment is no longer required and no published speed restriction applies to the segment ahead, the controlling facility will instruct the pilot to RESUME NORMAL SPEED. RESUME NORMAL SPEED cancels only the ATC-assigned speed adjustment; it does not cancel a published speed restriction on a procedure ahead, or the speed limits established in subparagraph i.

Example: Resume Normal Speed Center: "Falcon Two Two, maintain two two zero knots until BALTR, then resume normal speed." Pilot: "Maintain two two zero knots until BALTR, then resume normal speed, Falcon Two Two."

39.f.(2) When a pilot is joining or resuming a charted procedure that carries a published speed restriction, the controlling facility will instruct the pilot to COMPLY WITH SPEED RESTRICTIONS.

Example: Comply with Speed Restrictions Departure: "Republic Eight Ten, resume the SALTY ONE departure, comply with speed restrictions." Pilot: "Resume the SALTY ONE departure, comply with speed restrictions, Republic Eight Ten."

39.f.(3) When an ATC-assigned speed adjustment is no longer required and a published speed restriction applies to the segment ahead, the controlling facility will instruct the pilot to RESUME PUBLISHED SPEED. After receiving RESUME PUBLISHED SPEED, the pilot should begin adjusting speed far enough in advance of the next published fix to cross that fix at the published speed.

Example: Resume Published Speed Approach: "Falcon Two Two, maintain two two zero knots until BALTR, then resume published speed." Pilot: "Maintain two two zero knots until BALTR, then resume published speed, Falcon Two Two."

39.f.(4) When neither an ATC-assigned speed adjustment nor a published speed restriction is required any longer, the controlling facility will instruct the pilot to DELETE SPEED RESTRICTIONS. Before issuing DELETE SPEED RESTRICTIONS, the controlling facility must ensure obstacle clearance for the aircraft until it is established on a route with no published speed restriction.

Example: Delete Speed Restrictions Center: "Jetstream Four Seven, delete speed restrictions." Pilot: "Delete speed restrictions, Jetstream Four Seven."

39.f.(5) When clearing a departing or arriving aircraft to fly a SID or STAR under its own vertical navigation, the controlling facility will instruct the pilot to CLIMB VIA (the SID) or DESCEND VIA (the STAR). CLIMB VIA and DESCEND VIA cancel any previously issued ATC speed and altitude restrictions. The pilot will vertically navigate the procedure and will comply with every altitude and speed restriction depicted on it. When descending on a STAR under a DESCEND VIA clearance, the pilot should not increase speed significantly above the previously assigned speed.

Example: Climb Via Departure: "United Four Three Six, climb via SID." Pilot: "Climb via SID, United Four Three Six."

Example: Descend Via Approach: "Gulfstream Two Three Papa Echo, descend via the Tyler One arrival." Pilot: "Descend via the Tyler One arrival, Gulfstream Two Three Papa Echo."

39.g. Speed Control on Approach.

39.g.(1) On issuance of an approach clearance, any previously issued ATC speed adjustment is superseded.

39.g.(2) After a speed adjustment is superseded under (1), the pilot manages the aircraft's speed to complete the approach at the pilot's discretion, in accordance with the aircraft's approach procedure and stabilized-approach criteria; no standard speed applies at this point, by design.

39.g.(3) After issuing an approach clearance, the controlling facility (normally Approach) may still issue a further speed adjustment to maintain separation.

39.g.(4) Inside the final approach fix (FAF), or within 5 NM [VERIFY: source states "5 miles" without specifying nautical or statute miles] of the runway, whichever point is closer to the runway, the controlling facility must not assign a speed adjustment.

39.h. Pilot Rejection for Minimum Safe Airspeed.

39.h.(1) When the minimum safe airspeed for the aircraft's configuration or the operation being conducted is greater than an assigned speed adjustment, the pilot may reject that speed adjustment.

39.h.(2) After rejecting a speed adjustment under (1), the pilot must advise the controlling facility of the speed the pilot will use instead.

Example: Rejecting a Speed Adjustment Approach: "Cessna Three Four Kilo, reduce speed to one one zero knots." Pilot: "UNABLE one one zero knots, Cessna Three Four Kilo will maintain one two zero knots, our minimum safe speed in this configuration."

39.i. Mandatory Rejection of an Excessive Speed Assignment.

39.i.(1) When an assigned speed adjustment exceeds the maximum indicated airspeed permitted for the aircraft's altitude or airspace by 14 CFR 91.117(a), (c), or (d), the pilot must reject the assigned speed. The pilot must inform the controlling facility of the rejection.

39.i.(2) When a pilot has been assigned a speed greater than 250 knots IAS above 10,000 feet MSL and is subsequently cleared below 10,000 feet MSL, the pilot must reduce speed to comply with the 250-knot IAS limit in 14 CFR 91.117(a), without waiting for a further speed instruction from the controlling facility.

39.j. Applicability of the 250-Knot Restriction Offshore.

39.j.(1) Beyond 12 nautical miles from the coastline, within the United States Flight Information Region, in Class E airspace below 10,000 feet MSL, the 250-knot IAS restriction in 14 CFR 91.117(a) does not apply to a U.S.-registered aircraft.

39.j.(2) In airspace underlying Class B airspace, or within a Class B VFR corridor, the pilot must comply with the 200-knot IAS limit in 14 CFR 91.117(c), regardless of (1) above.

39.k. Speed Authorization in Class C and Class D Surface Areas. Within a Class C or Class D surface area, the controlling facility having jurisdiction over that surface area (Tower, or Approach, as applicable) may authorize a speed greater than the maximum indicated airspeed otherwise prescribed for that airspace. This authorization does not extend to the 200-knot limit established in subparagraph j.(2).

39.l. Reporting an Assigned Speed Restriction on Frequency Change. On initial contact with a controlling facility after an ATC-directed frequency change, the pilot should state any speed restriction currently assigned by ATC.

Example: Reporting an Assigned Speed Restriction Pilot (call sign "Falcon Two Two," assigned 220 knots by the prior facility): "Denver Center, Falcon Two Two, flight level three three zero, two two zero knots assigned."

Note: Which facility (Center, Approach, Departure, or Tower) holds speed-control responsibility at any given transition point is briefed every mission.

4.40 Runway Separation

This paragraph establishes Tower's authority to sequence arriving and departing aircraft on the runway, and the HOLD, EXTEND DOWNWIND, and IMMEDIATE terms used in that sequencing.

40.a. Sequencing Authority.

40.a.(1) When arriving and departing aircraft require spacing on the runway, Tower WILL issue a holding, spacing, or timing instruction to the affected aircraft. The specific instruction issued is at Tower's discretion, based on the traffic present at the time.

Note: The affected aircraft may be airborne (a flight operation) or still on the ground awaiting departure (a ground operation); Tower's authority under this subparagraph covers both.

40.a.(2) On receiving an instruction issued under (1), the pilot MUST comply with it.

40.b. Hold Instruction (HOLD). To achieve spacing between a departing aircraft and an arriving aircraft, Tower MAY instruct the departing aircraft to HOLD short of the runway.

Example: HOLD Instruction Tower: "November One Two Three Alpha Bravo, HOLD short runway two seven, traffic on a two mile final." Pilot: "HOLD short runway two seven, November One Two Three Alpha Bravo."

40.c. Extend Downwind Instruction (EXTEND DOWNWIND). To establish spacing from an arriving or departing aircraft, Tower MAY instruct a pilot in the traffic pattern to EXTEND DOWNWIND.

Example: EXTEND DOWNWIND Instruction Tower: "Cessna Three Four Six Tango, EXTEND DOWNWIND, I'll call your base." Pilot: "EXTEND DOWNWIND, Cessna Three Four Six Tango."

40.d. Immediate Takeoff Clearance (IMMEDIATE).

40.d.(1) When issuing a takeoff clearance for runway separation, Tower MAY include the term IMMEDIATE in the clearance.

Example: Immediate Takeoff Clearance Tower: "November One Two Three Alpha Bravo, cleared for IMMEDIATE takeoff, runway two seven." Pilot: "Cleared for IMMEDIATE takeoff, runway two seven, November One Two Three Alpha Bravo."

40.d.(2) If, in the pilot's judgment, complying with an IMMEDIATE takeoff clearance would adversely affect the operation, the pilot MAY decline it; otherwise, the pilot executes the clearance as issued.

Note: Decline phraseology is at the pilot's discretion; standard phraseology (for example, UNABLE) applies.

Example: Declining an Immediate Takeoff Clearance Tower: "November One Two Three Alpha Bravo, cleared for IMMEDIATE takeoff, runway two seven." Pilot: "UNABLE immediate, November One Two Three Alpha Bravo, ready for normal release." Tower: "November One Two Three Alpha Bravo, ROGER, HOLD short runway two seven."

Note: Gate holding due to departure delays is established in AIM 4-3-15, Gate Holding due to Departure Delays. That section was not among the sub-chapters consolidated into this contract; this citation is retained for cross-reference to that source section rather than to a paragraph of this chapter. [VERIFY: if AIM 4-3-15 is drafted into this contract in a later pass, renumber this citation to the resulting paragraph.]

4.41 Visual Separation

This paragraph establishes the two methods by which ATC separates aircraft by visual reference rather than by instrument-based separation minima, the obligations a pilot incurs on accepting a visual separation instruction, and the scanning discipline required to sustain visual contact. It is the authoritative statement, in this chapter, of the pilot's general visual-scanning and see-and-avoid duty; other paragraphs that invoke that duty (for example, paragraphs 4.6.a, 4.9.e(1), 4.29.d, and 4.38.b(2)) cross-reference subparagraph f below rather than restate it.

41.a. General. Visual separation is applied in terminal and en route airspace by either of two methods: Tower-executed visual separation, in which the controller in the tower cab visually observes both aircraft and issues instructions directly (see subparagraph b); or pilot-executed visual separation, in which the controller instructs a pilot who has visually acquired another aircraft to maintain separation from it (see subparagraph c).

41.b. Tower-Executed Visual Separation. When Tower visually observes both aircraft involved, Tower will issue instructions as necessary to keep the aircraft clear of each other. This method requires an unobstructed line of sight from the tower cab and is not available to a facility working the aircraft by radar alone.

41.c. Pilot-Executed Visual Separation.

41.c.(1) When the controlling facility (Tower, Approach, Departure, or Center) instructs a pilot to follow, or to maintain visual separation from, another aircraft, the pilot will report the traffic IN SIGHT to the controlling facility before accepting the instruction. Once the pilot has accepted the instruction, the pilot must maintain constant visual surveillance of that aircraft. The pilot must not pass the other aircraft until it is no longer a factor.

Note: Traffic is no longer a factor when, during the approach phase, the other aircraft enters the landing phase of flight or executes a missed approach; or, during departure or en route operations, when the other aircraft turns away or is on a diverging course. Until one of these events occurs, the pilot's separation responsibility continues.

41.c.(2) By accepting an instruction to follow, or to maintain visual separation from, another aircraft, the pilot commits to maneuvering the aircraft as necessary to avoid that aircraft or to maintain the in-trail spacing the controller has specified.

41.c.(3) A pilot may decline an instruction to follow, or to maintain visual separation from, another aircraft, even with that traffic in sight. If the pilot does not accept the instruction, the controlling facility will provide separation by another method (radar or non-radar, as the situation requires).

Example: Visual Separation, Approach Instruction and Acceptance Approach: "Cessna Four November Charlie, traffic, eleven o'clock, four miles, opposite direction, an MD-80 descending through five thousand five hundred." Pilot: "Cessna Four November Charlie, traffic in sight." Approach: "Cessna Four November Charlie, maintain visual separation from that traffic, descend and maintain four thousand." Pilot: "Maintain visual separation, descend and maintain four thousand, Cessna Four November Charlie."

41.d. Wake Turbulence and Super-Category Restriction.

41.d.(1) When a pilot accepts a visual separation instruction from, or is instructed to follow, an aircraft operating with a "Heavy" callsign suffix, or is flying a small aircraft following a Boeing 757 or other large aircraft, the pilot's acceptance also constitutes acceptance of responsibility for wake-turbulence avoidance from that aircraft. Otherwise, acceptance of a visual separation instruction carries no wake-turbulence responsibility beyond the standard collision-avoidance duty (see subparagraph c.(1)). This wake-turbulence responsibility is distinct from the intersection-departure interval established in paragraph 4.22.f–h, Intersection Takeoffs.

41.d.(2) When the other aircraft is in the "Super" wake-turbulence category (the weight category reserved for the largest transport aircraft, e.g., the Antonov An-225 or Airbus A380), a controller must not assign, and a pilot must not accept, a visual separation instruction involving it. Standard instrument-based separation applies instead.

Example: Visual Separation Behind a Large Aircraft Tower: "Cessna Four November Charlie, number two, following a company Boeing Seven Five Seven on a two mile final, traffic in sight?" Pilot: "Cessna Four November Charlie, traffic in sight." Tower: "Cessna Four November Charlie, maintain visual separation, cleared to land runway two seven." Pilot: "Maintain visual separation, cleared to land two seven, Cessna Four November Charlie."

Note: Because Cessna Four November Charlie is a small aircraft following a Boeing 757, the acceptance above also accepts wake-turbulence separation responsibility (see subparagraph d.(1)).

41.e. Loss of Visual Contact. When a pilot who has accepted a visual separation instruction loses sight of the other aircraft, cannot maintain visual contact with it, or cannot continue to accept separation responsibility for any reason, the pilot should promptly advise the controlling facility of that fact, using NEGATIVE CONTACT or UNABLE as applicable. The controlling facility will then re-establish separation by another method; the specific instruction used is at controller discretion and is not standardized by this subparagraph.

Example: Reporting Lost Visual Contact Pilot: "Approach, Cessna Four November Charlie, NEGATIVE CONTACT, UNABLE visual separation." Approach: "Cessna Four November Charlie, ROGER, turn left heading two seven zero, descend and maintain three thousand five hundred for separation."

Note: The heading and altitude above illustrate one possible controller response and are not a documented standard; the actual instruction depends on the traffic situation at the time (controller discretion).

41.f. Visual Scanning for Collision Avoidance.

41.f.(1) When weather conditions permit visual acquisition of other traffic, each pilot must see and avoid other aircraft under the real-world right-of-way rule at 14 CFR 91.113(a). Each pilot and copilot should continuously scan all sky area visible from the cockpit, alternating external scanning with instrument monitoring (timesharing). Each pilot must develop a scanning technique that maximizes coverage of the visible sky.

41.f.(2) Effective scanning should be performed as a series of short, regularly spaced eye movements rather than a continuous sweep, because the eye resolves detail only within a narrow area at a time. Each eye movement should not exceed 10 degrees of scan arc, and each area should be observed for a minimum of 1 second before shifting, since sustained detection of converging traffic requires that dwell time.

Note: 14 CFR 91.113(a) is cited as the real-world basis for the see-and-avoid duty. No certificate action follows from this paragraph inside the simulator, and the duty applies equally to airline, military, formation, and general-aviation traffic.

References

This chapter consolidates the following 41 source sections:

4.1. AIM 4-1-1 — Air Route Traffic Control Centers 4.2. AIM 4-1-2 — Control Towers 4.3. AIM 4-1-8 — Approach Control Service for VFR Arriving Aircraft 4.4. AIM 4-1-9 — Traffic Advisory Practices at Airports Without Operating Control Towers 4.5. AIM 4-1-13 — Automatic Terminal Information Service (ATIS) 4.6. AIM 4-1-15 — Radar Traffic Information Service 4.7. AIM 4-1-16 — Safety Alert 4.8. AIM 4-1-17 — Radar Assistance to VFR Aircraft 4.9. AIM 4-1-18 — Terminal Radar Services for VFR Aircraft 4.10. AIM 4-2-2 — Radio Technique 4.11. AIM 4-2-3 — Contact Procedures 4.12. AIM 4-2-4 — Aircraft Call Signs 4.13. AIM 4-2-6 — Ground Station Call Signs 4.14. AIM 4-2-7 — Phonetic Alphabet 4.15. AIM 4-2-8 — Figures 4.16. AIM 4-2-9 — Altitudes and Flight Levels 4.17. AIM 4-2-10 — Directions 4.18. AIM 4-2-11 — Speeds 4.19. AIM 4-2-12 — Time 4.20. AIM 4-3-2 — Airports with an Operating Control Tower 4.21. AIM 4-3-3 — Traffic Patterns 4.22. AIM 4-3-10 — Intersection Takeoffs 4.23. AIM 4-3-12 — Low Approach 4.24. AIM 4-3-14 — Communications 4.25. AIM 4-3-16 — VFR Flights in Terminal Areas 4.26. AIM 4-3-18 — Taxiing 4.27. AIM 4-3-21 — Exiting the Runway After Landing 4.28. AIM 4-3-23 — Option Approach 4.29. AIM 4-4-1 — Clearance 4.30. AIM 4-4-2 — Clearance Prefix 4.31. AIM 4-4-3 — Clearance Items 4.32. AIM 4-4-4 — Amended Clearances 4.33. AIM 4-4-6 — Special VFR Clearances 4.34. AIM 4-4-7 — Pilot Responsibility upon Clearance Issuance 4.35. AIM 4-4-8 — IFR Clearance VFR-on-top 4.36. AIM 4-4-9 — VFR/IFR Flights 4.37. AIM 4-4-10 — Adherence to Clearance 4.38. AIM 4-4-11 — IFR Separation Standards 4.39. AIM 4-4-12 — Speed Adjustments 4.40. AIM 4-4-13 — Runway Separation 4.41. AIM 4-4-14 — Visual Separation

Note: AIM 4-3-15, Gate Holding due to Departure Delays, is cited in paragraph 4.40 but was not among the sections assigned for consolidation into this chapter; it is not included in this References list and is not covered by this chapter's paragraph numbering.

Chapter 5 — Air Traffic Procedures

Purpose

This chapter establishes the procedures a pilot and the controlling facilities follow across the four phases of a flight: preflight preparation and flight-plan filing, departure, en route navigation and communication, and arrival, approach, and landing. It states the calls, thresholds, and compliance duties that apply from before a flight is filed to landing or missed approach. It applies without regard to operator category (civil, general aviation, air carrier, or military/formation) unless a paragraph states otherwise.

Scope

This chapter governs flight-plan filing, activation, revision, closure, and cancellation; ground and departure-clearance procedures; en route communication, position reporting, route selection, and holding; and arrival, approach-clearance, approach-chart, landing-minimums, missed-approach, visual-approach, contact-approach, and overhead-maneuver procedures, adapted for the simulated environment from 32 source paragraphs of the real-world Aeronautical Information Manual (AIM), Chapter 5.

This chapter does not establish: the general airspace-classification and equipment rules of Chapter 3; the ATC clearance, separation, speed-adjustment, and traffic-pattern procedures of Chapter 4; two-way radio communications failure procedures (the source AIM's Chapter 6, not adapted into this contract); pilot weather reports or cold-temperature altimetry procedures (the source AIM's Chapter 7, not adapted into this contract); or the aircraft approach-category speed breakpoints, which are defined in the Pilot/Controller Glossary. It also does not restate the NOTAM system, flights outside the U.S. and U.S. territories, national security and interception procedures, special instrument approach procedures, radar monitoring of instrument approaches, simultaneous-approach procedures, charted visual flight procedures, or helicopter-specific missed-approach procedures. Each of these is a topic of the source AIM's own Chapter 5 that was not among the 32 sub-chapters aggregated into this contract; where a paragraph below names one, it does so only as a descriptive pointer, never as a numbered cross-reference into this chapter.

Paragraphs are numbered 5.1 through 5.32, grouped under four headings in flight-phase order: Preflight (5.1–5.8), Departure (5.9–5.14), En Route (5.15–5.20), and Arrival (5.21–5.32). A citation to a sub-paragraph takes the form 5.n.l.(1), for example 5.21.k.(2). A term defined once for the whole chapter appears in the master Glossary at the end of this contract; where a paragraph's own "Controlled Terms" subparagraph is present, it defines only the terms local to that paragraph.

Preflight

This part establishes what a pilot gathers and files before departure, namely a weather and airspace briefing and a VFR, DVFR, or IFR flight plan containing a defined set of elements, and the revision, closure, and cancellation procedures that keep that flight plan current from filing through landing.

5.1 Preflight Preparation

This paragraph establishes what each pilot gathers and files before a flight begins: a weather and airspace briefing, a flight plan containing a defined set of elements, and, for a cross-border or long-range flight, a progress itinerary left with another person. It applies to civil, military, and air-taxi-style traffic alike; no category of traffic is exempt.

This paragraph does not establish the format of a Notice to Air Missions (NOTAM) or the network's own special-notices system, or the procedures governing flights outside the U.S. beyond leaving an itinerary (both are topics of the source AIM's Chapter 5 not included in this contract), or the call sign spoken on frequency (established in paragraph 4.12, Aircraft Call Signs).

a. Weather and Airspace Information

(1) Before requesting taxi, pushback, an IFR clearance, or entry into airspace served by Air Traffic Control (ATC), each pilot SHOULD obtain a weather and airspace briefing for the route of flight, using the simulation platform's own weather and chart tools, the network's special-notices page, or a real-world weather source the mission briefing designates.

(2) When a Flight Service Station (FSS) position is staffed on the network, the pilot MAY contact FSS for that briefing instead of self-briefing; when no FSS position is staffed, the pilot self-briefs under (1) above.

Example: Preflight Briefing Request to FSS Pilot (call sign "Cessna 4567X"): "Seattle Radio, Cessna Four Five Six Seven X-ray, request a preflight briefing, VFR from Boeing Field to Paine Field, eight thousand five hundred, proposed departure one eight three zero Zulu." FSS ("Seattle Radio"): "Cessna Four Five Six Seven X-ray, Seattle Radio, standby for briefing... [current altimeter, winds, and any notices affecting your route follow]."

Note: VFR and IFR are defined in the Pilot/Controller Glossary; this paragraph does not restate either.

b. Flight Plan Filing

(1) Before requesting an IFR clearance, or before operating in airspace that requires a filed flight plan under the network's rules, each pilot WILL file a flight plan through the network's flight-plan interface, containing the elements in Table 1.

Table 1. Flight Plan and Briefing Elements

#	Element	Example
1	Flight rules	VFR or IFR
2	Call sign / aircraft identification	N1234B
3	Aircraft type	C172, B738
4	Departure point	KBFI
5	Route of flight	direct, or named airways and fixes
6	Destination	KPAE
7	Cruising altitude(s)	8,500 ft MSL
8	Proposed departure time (ETD) and estimated time en route (ETE)	1830Z, 0+45

Legend: VFR = Visual Flight Rules; IFR = Instrument Flight Rules; MSL = mean sea level; ETD = estimated time of departure; ETE = estimated time en route.

(2) When requesting a briefing from a staffed FSS position instead of self-briefing under a.(1) above, the pilot WILL give FSS the elements in Table 1, so FSS can tailor the briefing to the flight.

Note: This paragraph does not prescribe a specific flight-plan document; each network defines its own flight-plan interface and field layout, and Table 1 states the content a pilot supplies to it, not a form number.

Note: On most networks, a military flight plan is filed through the same interface as a civil flight plan, distinguished only by aircraft type and call sign (discretion: filing-system specifics vary by network).

c. NOTAMs and Special Notices

(1) When FSS gives a briefing under a.(2) above, FSS WILL include pertinent NOTAM-equivalent special notices affecting the route of flight, for example temporary airspace restrictions, closures, or event notices; when FSS omits them, the pilot MAY ask for them directly.

(2) When planning to fly a special, non-public instrument approach procedure, the pilot MUST request notice information for that procedure specifically; a standard briefing under (1) above does not include it.

d. Chart and Navigation Data Currency

(1) When planning and conducting a flight, each pilot SHOULD use the current charts and navigation data for the simulation platform in use.

Note: Real-world aeronautical charts and IFR en route charts are revised on a 56-day cycle, with civil IFR approach chart amendments on the same 56-day cycle and a change-notice volume at the 28-day midpoint. The update cycle for a given simulation platform's own scenery and navigation data is set by that platform, not by this paragraph (discretion).

e. Slot-Controlled Airports and Events

(1) When a special notice designates an airport or a scheduled network event as slot-controlled, the pilot MUST obtain the reservation that notice requires before departure, following the procedure the notice states (briefed every mission: no standing reservation procedure exists in this paragraph).

f. Cross-Border and Long-Range Itineraries

(1) When a flight's route crosses into another country's airspace, or covers an extended overwater or remote segment, the pilot SHOULD leave a complete itinerary (route, ETD, ETE, and destination) with another person (a virtual airline operations desk, an event coordinator, or another pilot) and keep that person updated on the flight's progress; otherwise, no itinerary is required.

(2) If serious doubt arises about the flight's safety or status, the person holding the itinerary under (1) above SHOULD first contact FSS or the network's duty staff, where available.

g. Call Sign Prefix for Non-Designated Operators

(1) When filing a flight plan for a non-scheduled or on-demand, Part-135-style operation without an assigned three-letter operator designator, the pilot MAY prefix the registration number with the letter T in the flight plan's aircraft identification field, for example N1234B filed as TN1234B (discretion: enforcement of this convention is network-specific).

Note: The voice call sign spoken on frequency follows the TANGO-prefix convention established in paragraph 4.12, Aircraft Call Signs. This paragraph's "T" prefix applies to the written flight-plan identification field only, not to what the pilot says on frequency.

5.2 VFR Flight Plans

This paragraph establishes procedures for filing, activating, revising, and reporting position under a Visual Flight Rules (VFR) flight plan in the simulator. "FSS" carries the meaning established in the Glossary. "The network's flight-plan system" means the electronic flight-plan tool the connecting network provides for filing and activation when no FSS is staffed. [VERIFY: the name and exact behavior of that tool vary by network (e.g., VATSIM, IVAO, PilotEdge) and are established in that network's own procedures, not in this document.]

a. Filing Requirement. Except where paragraph b, c, or d of this paragraph applies, filing a VFR flight plan is optional; a VFR flight within the host network's domestic airspace does not require one.

b. Air Defense Identification Zones. Before entering an Air Defense Identification Zone (ADIZ) that the simulator models, each pilot other than one operating as Department of Defense (DoD) or law-enforcement traffic must file a Defense VFR (DVFR) flight plan with the FSS. DoD and law-enforcement flights are exempt from this filing requirement. REFERENCE: 14 CFR Part 99. Note: Interception and identification procedures for ADIZ penetration are a topic of the source AIM's Chapter 5 not included in this contract.

c. Special Flight Rules Areas. When operating within a Special Flight Rules Area (SFRA) that the host event or facility models (for example, a Washington, DC-area SFRA), each pilot must follow the DVFR filing, equipment, and position-reporting procedures published for that area (briefed every mission).

d. International Flights. Before a VFR flight to a destination outside the host country, each pilot must file and activate a VFR flight plan.

Table 1. VFR Flight Plan Filing and Activation Requirements by Circumstance

Circumstance	Flight Plan Type	Filing	Activation
Domestic flight, no special airspace	VFR	SHOULD (recommended, para. e)	Required only if filed (para. g)
ADIZ penetration, non-DoD/non-law-enforcement	DVFR	MUST	MUST
SFRA operation (event/facility-modeled)	DVFR or VFR per brief	MUST (briefed every mission)	MUST
International destination	VFR	MUST	MUST

Legend: ADIZ = Air Defense Identification Zone; DVFR = Defense Visual Flight Rules; SFRA = Special Flight Rules Area; VFR = Visual Flight Rules.

e. Recommended Filing Practice. Where paragraph b, c, or d of this paragraph does not already require one, each pilot should file a VFR flight plan with the FSS or the network's flight-plan system. Note: Filing alone gives no flight-following or search-and-rescue benefit until the flight plan is activated (see paragraph g).

f. Stopover Flights. When a flight includes an intermediate stop before its final destination, each pilot should file a separate VFR flight plan for each leg.

g. Activation. Once airborne on a route covered by a filed VFR flight plan, each pilot will activate that flight plan with the FSS, as soon as practical, by radio or through the network's flight-plan system (method: pilot's discretion). Tower and Ground will not activate a VFR flight plan; only the FSS, or the network's flight-plan system where no FSS is staffed, can do so.

EXAMPLE: VFR Flight Plan Activation Call

Speaker	Transmission
Pilot	"Seattle Radio, Cessna Five Zero Eight Three Hotel, activate VFR flight plan, Boeing Field to Yakima, off at three five."
FSS	"Cessna Five Zero Eight Three Hotel, Seattle Radio, VFR flight plan activated at three five, have a good flight."

Note: Callsign, station name, and time are illustrative; use the callsign, route, and off-time actually filed.

h. Flight Plan Retention Window. A filed VFR flight plan that is not activated within 2 hours of its proposed departure time will be purged by the flight-plan system. Activating a purged flight plan requires filing a new one.

i. Assumed Departure Time. Each pilot may activate a VFR flight plan by filing an assumed departure time with it instead of calling the FSS after takeoff. An assumed departure time activates the flight plan automatically at the time filed, without a radio or system call. When the actual departure time, route, or estimated time of arrival (ETA) changes from what was filed, each pilot must update the FSS with the revision. Note: Search-and-rescue timing is based on the assumed departure time on file. An unrevised assumed departure time causes any search-and-rescue action modeled by the event to start against the wrong time.

EXAMPLE: Assumed Departure Time Revision Call

Speaker	Transmission
Pilot	"Seattle Radio, Cessna Five Zero Eight Three Hotel, revise proposed departure time on my VFR flight plan, Boeing Field to Yakima, new departure time four five."
FSS	"Cessna Five Zero Eight Three Hotel, Seattle Radio, departure time revised to four five."

j. Position Reports. While operating on an active VFR flight plan, each pilot should report position to the FSS periodically along the route. Note: Position reports are not required to keep a VFR flight plan active; unlike some IFR position-reporting requirements, a missed report does not by itself trigger action.

EXAMPLE: VFR Position Report

Speaker	Transmission
Pilot	"Seattle Radio, Cessna Five Zero Eight Three Hotel, position report, over Ellensburg at five three, six thousand five hundred, estimating Yakima at one five."
FSS	"Cessna Five Zero Eight Three Hotel, Seattle Radio, copy your position, Yakima at one five."

k. Cruising Altitude. When conducting level cruising flight more than 3,000 ft above ground level (AGL), each pilot must maintain a VFR cruising altitude appropriate to the aircraft's magnetic course: an odd thousand-foot altitude plus 500 ft mean sea level (MSL) (for example, 5,500 ft MSL) for a magnetic course of 000-179 degrees, or an even thousand-foot altitude plus 500 ft MSL (for example, 6,500 ft MSL) for a magnetic course of 180-359 degrees. REFERENCE: 14 CFR 91.159. Note: Below 3,000 ft AGL, no VFR hemispheric altitude rule applies; altitude selection is at the pilot's discretion, subject to any minimum safe altitude and airspace requirements established elsewhere.

l. Equipment Suffix. When filing a VFR flight plan, each pilot will enter the aircraft's equipment suffix using the same equipment codes required for an IFR flight plan, established in paragraph 5.3, IFR Flight Plan Filing and Route Description.

Note: Closing an activated VFR flight plan is established in paragraph 5.7, Closing VFR and DVFR Flight Plans.

5.3 IFR Flight Plan Filing and Route Description

This paragraph establishes how a pilot fills in the route of an Instrument Flight Rules (IFR) flight plan, whether by airways, by direct fixes, or by Area Navigation (RNAV)/Global Navigation Satellite System (GNSS) waypoints, and the filing-timing and clearance-request practices specific to an IFR flight plan. It applies to civilian, military, and formation traffic alike; no category of traffic is exempt.

This paragraph does not establish the general flight-plan filing procedure or the base set of flight-plan elements, established in paragraph 5.1, Preflight Preparation, and does not restate which real-world government form a Department of Defense (DoD) aircrew completes, established in paragraph 5.4, Military and DoD Flight Plan Documentation.

a. Filing Timing and Duplicate Flight Plans

(1) Before requesting an IFR clearance, the pilot SHOULD file the IFR flight plan at least 30 minutes before the proposed departure time.

(2) For a non-scheduled IFR flight planned above Flight Level (FL) 230, the pilot SHOULD file at least 4 hours before the proposed departure time; this lead time is voluntary, not a standing requirement (discretion: a network or mission brief may set a shorter or longer figure).

(3) When Instrument Meteorological Conditions exist in the destination's Class B, Class C, Class D, or Class E surface area, the pilot SHOULD file the IFR flight plan before departure rather than requesting it after becoming airborne.

Note: Filing before departure under (1) and (3) above shortens the wait for a clearance and reduces the chance of a delay entering a controlled surface area on arrival.

(4) A pilot MUST NOT file a second IFR flight plan for the same flight while an earlier one for that flight remains active. When the route, altitude, or timing changes after filing, the pilot WILL close or cancel the earlier flight plan before filing the replacement.

Note: The flight plan's required elements and the filing interface itself are established in paragraph 5.1, Preflight Preparation.

b. IFR Clearance Requests

(1) When calling Clearance Delivery, Ground, Tower, or FSS to request an IFR clearance, the pilot WILL identify the departure airport by its name or its identifier, in addition to the call sign.

Example: Requesting an IFR Clearance from Clearance Delivery Pilot ("Skyward 412"): "Springfield Clearance, Skyward Four One Two, IFR to Riverton, request clearance." Clearance Delivery: "Skyward Four One Two, Springfield Clearance, cleared to Riverton Airport as filed, climb via SID, expect Flight Level two three zero ten minutes after departure, departure frequency one two four point five five, squawk four two one seven." Pilot: "Cleared to Riverton as filed, climb via SID, expect Flight Level two three zero ten minutes after departure, one two four point five five, four two one seven, Skyward Four One Two."

Note: Call signs, frequencies, and the route in this example are illustrative and not asserted as any real facility's actual values.

c. Route Description by Airways and Fixes

(1) When the route of flight follows a published airway or jet route, the pilot WILL name each airway or jet route by its designator, provided that airway or jet route is established for use at the filed altitude; when the route uses more than one airway or jet route, the pilot WILL identify the fix where the flight transitions from one to the next.

(2) When the route of flight is not fully described by airway designators, the pilot MAY instead name the NAVAIDs (navigational aids) or fixes the flight will pass over, provided each is established for use at the filed altitude, and MAY combine named fixes with airway segments in the same route; either way, the filed route WILL include enough points to be unambiguous to Air Traffic Control (ATC).

(3) When a preferred route is published for the departure and destination pair, the pilot SHOULD file that route; when no preferred route is published for that pair, the pilot files a route under (1) or (2) above.

Note: Filing a published preferred route under (3) above reduces the likelihood of a reroute before or during the flight.

Note: Which RNAV Standard Instrument Departure (SID) or Standard Terminal Arrival (STAR), established in paragraph 5.14, Instrument Departure Procedures, and paragraph 5.21, Standard Terminal Arrival (STAR) Procedures, ATC assigns depends on the navigation capability the pilot filed in the flight plan.

Example: Filing a Route by Airways and Fixes Route filed: KKSPI DCT FAM V4 STL V8 CIRUS KKMEM

d. Direct Routes

(1) When a portion of the route will not be flown on an established airway or jet route, the pilot MUST define that portion by naming the radio fixes, NAVAIDs, or waypoints along it, each established for use at the filed altitude.

(2) When naming NAVAIDs to define a direct portion under (1) above, the distance between consecutive NAVAIDs MUST NOT exceed the limit in Table 1 for the altitude flown.

Table 1. Maximum NAVAID Spacing for a Direct (Off-Airway) Route

#	Altitude Band	Maximum NAVAID Spacing
1	Below 18,000 ft MSL, off established airways	80 NM
2	14,500 ft MSL through 17,999 ft MSL, conterminous U.S. only	200 NM, using (H)-class facilities
3	18,000 ft MSL through FL 450, off established routes	260 NM
4	Above FL 450	200 NM

Legend: MSL = mean sea level; FL = Flight Level; NM = nautical miles; (H) = high-altitude NAVAID service volume. NAVAID service volumes are a topic of the source AIM's Chapter 1 (AIM 1-1-8, Navigational Aid (NAVAID) Service Volumes) that was not among the sub-chapters adapted into this contract's Chapter 1; the "(H)" designation is noted here for completeness but its underlying service-volume distances are not restated in this contract.

(3) When Center is providing radar monitoring along a direct segment, Center MAY assign or approve a direct route exceeding the spacing in Table 1.

Note: Radar monitoring substitutes for the navigational accuracy that the spacing in Table 1 otherwise protects, which is why Center may waive it under (3) above.

Example: Direct Routing Clearance from Center Center ("Great Lakes Center"): "Skyward Four One Two, cleared direct Riverton, radar contact, when able direct Riverton." Pilot: "Cleared direct Riverton, Skyward Four One Two."

Note: On a direct segment not defined by a published airway or a charted procedure, the pilot retains responsibility for terrain and obstruction clearance.

e. GNSS Point-to-Point Routes (Non-Radar)

(1) When a GNSS-equipped aircraft is flying a random RNAV route without radar monitoring, Center WILL clear the aircraft via, or confirm the aircraft is established on, a point-to-point route defined by published NAVAIDs, waypoints, fixes, or airports recallable from the aircraft's onboard navigation database.

(2) When non-radar separation is applied to a route under (1) above, the distance between consecutive points MUST NOT exceed 500 NM.

(3) Center protects the airspace 4 NM either side of the route centerline defined under (1) above.

(4) The assigned altitude for a route segment under (1) above MUST be at or above the highest Minimum IFR Altitude (MIA) along that segment, including the segment's protected airspace under (3) above.

Example: GNSS Point-to-Point Clearance Center ("Oceanic Center"): "Transcon Eight Eight, cleared to Coastal Intl via direct BRAVO, direct DELTA, direct destination, maintain Flight Level three five zero." Pilot: "Cleared to Coastal Intl via direct BRAVO, direct DELTA, direct destination, maintain Flight Level three five zero, Transcon Eight Eight."

f. Random RNAV Route Filing

(1) When filing a random RNAV route, the pilot WILL file the flight plan airport-to-airport; the random-route portion WILL begin and end over a published arrival or departure transition fix, and the pilot WILL file the route-structure segment connecting the random portion to that fix.

(2) When filing a random RNAV route, the pilot WILL indicate RNAV or Required Navigation Performance (RNP) capability in the flight plan, using the field the network's flight-plan filing interface provides for it. [VERIFY: which field, if any, a given network's filing interface uses for this is network-specific; confirm against that network's own documentation.]

(3) When filing the random-route portion, the pilot WILL define it by waypoints, at minimum one waypoint for each Center (Air Route Traffic Control Center, ARTCC) whose airspace the route crosses, plus one additional waypoint at each course change; the pilot MAY file further waypoints beyond that minimum as needed for accurate navigation along the route (discretion: the number needed depends on the specific route flown).

(4) When planning the random-route portion, the pilot MUST route it at least 3 NM clear of prohibited and restricted airspace, unless the agency controlling that airspace has granted permission to operate within it.

g. Latitude/Longitude Route Definition

(1) When defining the random-route portion by coordinates rather than by named waypoints, the pilot WILL state each turn point and the arrival fix as a latitude/longitude coordinate to the nearest minute, or as a Navigation Reference System (NRS) waypoint.

(2) When filing a random-route portion defined under (1) above, the pilot WILL file that portion at FL 390 or above.

(3) When flying a random-route portion defined under (1) above, the pilot WILL fly each segment on a great circle track between its defined points.

Note: Coordinate-based random routing is characteristic of oceanic and remote operations; whether a given mission uses this method is briefed every mission, not a standing default.

5.4 Military and DoD Flight Plan Documentation

This paragraph states the scope, as it applies to the simulator, of which government paper form a Department of Defense (DoD) aircrew completes when filing a flight plan in the real-world National Airspace System (NAS). It applies to every pilot in the simulator, civilian, general aviation, airline, or military, including formation flights. It does not cover flight-plan filing procedure for VFR or IFR flights, established in paragraph 5.2, VFR Flight Plans, and paragraph 5.3, IFR Flight Plan Filing and Route Description.

a. Source Content.

(1) Within U.S. controlled airspace, a DoD aircrew filing a flight plan in the real-world NAS uses Federal Aviation Administration (FAA) Form 7233-1 or Department of Defense (DD) Form 175.

(2) For a flight that departs U.S. controlled airspace, requests routing requiring Performance Based Navigation (PBN), or requests flight-plan services supported only in the international flight-plan format, DD Form 1801 is the required form in the real-world NAS; DD Form 1801 is also the recommended form for an IFR flight not meeting any of those three conditions.

Note: Paragraph a. is administrative/paperwork content. It states which government paper form a DoD aircrew completes, contains no radio call and no in-flight procedure, and establishes no rule binding a pilot in the simulator.

b. Applicability in the Simulator.

(1) No pilot in the simulator (civilian, general aviation, airline, or military, including formation flights) completes FAA Form 7233-1, DD Form 175, or DD Form 1801.

Note: Whether a given network's flight-plan filing system exposes a domestic/international format distinction, or Performance Based Navigation (PBN) capability fields, comparable to the real-world distinction in paragraph a., is network-specific. [VERIFY: not established by this paragraph; confirm against the specific network's own flight-plan filing documentation before briefing this to aircrew.]

5.5 DVFR Flight Plan Designation and Remarks

This paragraph establishes how a pilot designates a Defense VFR (DVFR) flight plan once filing one is required, and how a pilot declines search-and-rescue (SAR) coverage on a DVFR flight plan. It does not establish when a DVFR flight plan is required for entry into a simulated Air Defense Identification Zone (ADIZ), established in paragraph 5.2, VFR Flight Plans, and it does not establish interception or identification procedures for ADIZ penetration (a topic of the source AIM's Chapter 5 not included in this contract).

a. DVFR Flight Plan Type Designation

When filing a DVFR flight plan required under paragraph 5.2, VFR Flight Plans, the pilot WILL designate the flight's type as Defense VFR (DVFR) in the network's flight-plan system.

Note: In the real-world National Airspace System, this designation is made by entering the letter "D" in the Type of Flight field (Item 8) of Federal Aviation Administration (FAA) Form 7233-4 or Department of Defense (DD) Form 1801. [VERIFY: whether a given network's flight-plan system exposes a distinct DVFR selection, or instead treats a DVFR flight plan as a VFR flight plan carrying a remark, is network-specific; confirm against that network's own flight-plan filing documentation.]

b. Search-and-Rescue Coverage Waiver (NORIV)

When filing a DVFR flight plan, the pilot MAY decline search-and-rescue (SAR) coverage. When the pilot declines SAR coverage, the pilot WILL enter the remark NORIV, preceded by the indicator RMK/, in the flight plan's remarks field. Where the pilot does not decline SAR coverage, no NORIV remark applies, and the flight plan carries standard SAR coverage.

Example: Remarks Field Entry Declining SAR Coverage RMK/NORIV

c. DVFR Flight Plan Activation

Once airborne on a route covered by a filed DVFR flight plan, the pilot MUST activate that flight plan with FSS, following the activation procedure established in paragraph 5.2, VFR Flight Plans. Where the pilot has entered NORIV under paragraph b, the activation requirement still applies; NORIV changes only whether SAR coverage is expected, not whether the flight plan must be activated. After landing on a DVFR flight plan filed with NORIV, the pilot need not close the flight plan.

Note: The general procedure for closing a DVFR flight plan is established in paragraph 5.7, Closing VFR and DVFR Flight Plans. This paragraph states only the NORIV exception to that procedure.

Note: In the real-world National Airspace System, DVFR flight plan activation is also what notifies the North American Aerospace Defense Command (NORAD) for air-defense purposes. Which network or event function, if any, serves as the equivalent recipient in the simulator is network-specific. [VERIFY: confirm against the network's or event's own ADIZ-monitoring procedures; treat as briefed every mission where no standing network procedure exists.]

Example: Activating a DVFR Flight Plan Pilot ("Cessna 4567X"): "Seattle Radio, Cessna Four Five Six Seven X-ray, activate Defense VFR flight plan, Boeing Field to Bellingham, off at four zero." FSS ("Seattle Radio"): "Cessna Four Five Six Seven X-ray, Seattle Radio, Defense VFR flight plan activated at four zero."

Example: Activating a DVFR Flight Plan with a SAR Waiver Pilot ("Cessna 4567X"): "Seattle Radio, Cessna Four Five Six Seven X-ray, activate Defense VFR flight plan, Boeing Field to Bellingham, off at four zero, remarks NORIV." FSS ("Seattle Radio"): "Cessna Four Five Six Seven X-ray, Seattle Radio, Defense VFR flight plan activated at four zero, NORIV copied, no cancellation required on landing."

Note: Call sign, station name, route, and time in both examples are illustrative; use the call sign, route, and off-time actually filed.

5.6 Flight Plan Revision

This paragraph establishes the channel and timing a pilot uses to revise a filed IFR flight plan before departure. It does not establish the initial flight-plan filing procedure or route description, established in paragraph 5.3, IFR Flight Plan Filing and Route Description, and paragraph 5.2, VFR Flight Plans, or an ATC-initiated clearance amendment issued after departure, established in paragraph 4.29, Clearance. "Flight-plan service provider" means the online flight-planning system, application, or organization through which the pilot originally filed the flight plan (for example, the network's own flight-plan filing page, or a third-party flight-planning application feeding it), as distinct from a staffed FSS position or an ATC facility.

a. Cruising Speed Variance. The report a pilot gives when true airspeed at cruising altitude varies from the flight plan filed is an en route report; it is established in paragraph 5.17, Additional Reports, and is not restated here.

b. Flight Plan Revision Timing

(1) More than 46 minutes before the proposed departure time, the pilot MUST submit a flight plan revision to the flight-plan service provider that holds the original filing.

(2) If the flight-plan service provider is unavailable, the pilot MAY instead contact an ATC facility or FSS to make the revision.

(3) At 46 minutes or less before the proposed departure time, the pilot MUST coordinate the revision through an ATC facility or FSS instead of the flight-plan service provider.

Note: Making a revision more than 46 minutes before the proposed departure time, under (1) above, is what keeps the revision eligible to be made through the flight-plan service provider directly; waiting until 46 minutes or less forces live coordination under (3) above. [VERIFY: which ATC facility to call for this coordination in a given scenario (Clearance Delivery, Ground, or FSS) is not standardized; call whichever of those positions is staffed and appropriate to the pilot's location at the time (at discretion).]

Example: Flight Plan Revision Request Through FSS Pilot (call sign "Reach 3140"): "Example Radio, Reach Three One Four Zero, request to amend the IFR flight plan filed for Reach Three One Four Zero, change requested altitude to Flight Level two eight zero." FSS ("Example Radio"): "Reach Three One Four Zero, Example Radio, copy the amendment, requested altitude Flight Level two eight zero, the revision has been forwarded."

Note: An FSS is addressed on frequency by its location name followed by "Radio" (for example, "Seattle Radio"), not by the words "Flight Service Station." Call sign, facility name, and altitude in this example are illustrative and not asserted as any real facility's actual values.

Table 1. Flight Plan Revision Channel by Timing

#	Circumstance	Threshold	Required Channel
1	Flight plan revision	More than 46 minutes before proposed departure	Flight-plan service provider (MUST)
2	Flight plan revision, provider unavailable	More than 46 minutes before proposed departure	ATC facility or FSS (MAY)
3	Flight plan revision	46 minutes or less before proposed departure	ATC facility or FSS (MUST)

Legend: ATC = Air Traffic Control; FSS = Flight Service Station.

5.7 Closing VFR and DVFR Flight Plans

This paragraph establishes each pilot's responsibility for closing a VFR or DVFR flight plan, the accepted methods of closing one, and the search-and-rescue consequence of leaving one open. It applies to civil, military, and formation VFR/DVFR traffic alike; no category of traffic is exempt.

This paragraph does not establish the procedure for filing or activating a VFR or DVFR flight plan, established in paragraph 5.2, VFR Flight Plans, and does not establish the procedure for closing an IFR flight plan, established in paragraph 5.8, Canceling IFR Flight Plan.

a. Responsibility

(1) On completing a flight conducted under a VFR or DVFR flight plan, the pilot MUST close that flight plan.

b. Flight Service Closure

(1) When FSS contact is available, the pilot SHOULD close the flight plan with the nearest FSS. FSS acknowledges the closure to the pilot.

Example: Closing a VFR Flight Plan With Flight Service Pilot (call sign "Cessna 1234A"): "Elmwood Radio, Cessna One Two Three Four Alpha, closing VFR flight plan." FSS ("Elmwood Radio"): "Cessna One Two Three Four Alpha, flight plan closed, good day."

Note: Call sign and station name are illustrative and are not asserted as any real facility's actual designator.

c. ATC Relay Closure

(1) When FSS contact is not available, the pilot MAY request any other ATC facility in contact with the aircraft (for example, Tower, Ground, Departure, Approach, or Center) to relay the closure to FSS. The facility acknowledges the request before relaying it.

Example: Relaying Flight Plan Closure Through Approach Pilot (call sign "Cessna 1234A"): "Springfield Approach, Cessna One Two Three Four Alpha, request you relay closure of my VFR flight plan to Flight Service." Approach: "Cessna One Two Three Four Alpha, WILCO."

Note: Call sign and facility name are illustrative and are not asserted as any real facility's actual designator.

d. Non-Automatic Closure by Tower

(1) Regardless of landing at a towered airport or contact with any ATC facility, a VFR or DVFR flight plan is not closed automatically.

(2) Closure still requires action under paragraph b or c above.

Note: Tower and other ATC facilities do not track which VFR or DVFR aircraft are operating on a flight plan, so they cannot close one automatically.

e. Search-and-Rescue Trigger

(1) If the pilot has not closed the flight plan, or otherwise reported, within 30 minutes after the filed estimated time of arrival (ETA), FSS WILL initiate search-and-rescue (SAR) notification procedures.

Note: This 30-minute trigger is the documented real-world FSS search-and-rescue standard. Whether a missed closure triggers a simulated search-and-rescue response on a given network, and what that response involves, is at the discretion of the controlling facility or event staff. [VERIFY: not established by this paragraph; confirm against the specific network's own procedures before briefing this to aircrew.]

5.8 Canceling IFR Flight Plan

This paragraph establishes how a pilot cancels an IFR flight plan by radio, the effect cancellation has on ATC services, and the distinct methods by which an IFR flight plan closes at a towered airport versus a non-towered airport. It applies to civil, military, and formation traffic alike; no category of traffic is exempt.

This paragraph does not establish the procedure for filing an IFR flight plan, established in paragraph 5.3, IFR Flight Plan Filing and Route Description. It does not establish the procedure for closing a VFR or DVFR flight plan, established in paragraph 5.7, Closing VFR and DVFR Flight Plans. It does not establish two-way radio communications failure procedures, established in the source AIM's Chapter 6, Two-Way Radio Communications Failure, which is not adapted into this contract.

a. General Requirement.

(1) Upon completing IFR operation on an active IFR flight plan, or upon electing to continue the flight in VFR conditions instead, each pilot must ensure the flight plan is closed, using the method applicable to the pilot's situation under this paragraph.

REFERENCE: 14 CFR 91.153, 91.169.

b. Cancellation by Radio.

(1) When operating in VFR conditions outside Class A airspace, the pilot may cancel the IFR flight plan by radio, stating "CANCEL MY IFR FLIGHT PLAN" to the facility currently providing IFR service to the flight (Center, Approach, or another facility, as applicable) or to FSS.

Example: Canceling an IFR Flight Plan by Radio Pilot (call sign "Cessna 34B"): "Example Approach, Cessna Three Four Bravo, cancel my IFR flight plan." Approach: "Cessna Three Four Bravo, IFR flight plan canceled, squawk VFR, radar service terminated, frequency change approved."

(2) Immediately after canceling the IFR flight plan under (1) above, the pilot should change to the appropriate air-to-ground frequency, select the VFR transponder code (1200 in the contiguous United States; the applicable code may differ elsewhere), and adjust to a VFR-appropriate altitude or flight level.

c. Effect on ATC Services.

(1) Once a facility accepts a cancellation under b.(1) above, the facility will discontinue ATC separation and traffic information services, including radar service where applicable.

(2) If the pilot wants to continue receiving VFR radar advisories after canceling, the pilot must specifically request them; otherwise, no radar advisory service is provided after cancellation.

Example: Requesting VFR Radar Advisories After Cancellation Pilot: "Example Approach, Cessna Three Four Bravo, cancel my IFR flight plan, request VFR flight following to Example Municipal." Approach (advisories available): "Cessna Three Four Bravo, IFR canceled, squawk zero four one three, radar contact, flight following to Example Municipal approved." Approach (advisories not available): "Cessna Three Four Bravo, IFR canceled, unable flight following due to workload, squawk VFR, frequency change approved."

Note: Providing VFR radar advisories after a cancellation is subject to facility workload; requesting them under (2) above does not guarantee they will be provided.

Note: Additional procedures may apply within a Terminal Radar Service Area (TRSA), Class C airspace, or Class B airspace; where such a program is established for the facility, those procedures are briefed every mission.

d. DVFR Flight Plan Requirement After Cancellation.

(1) Where a DVFR flight plan requirement applies to the route of flight (for example, an ADIZ crossing that the facility or network models), the pilot must file the DVFR flight plan to replace the canceled IFR flight plan; otherwise, no additional flight-plan filing is required.

Note: Whether an ADIZ or DVFR requirement applies to a given route depends on the facility's or network's modeled airspace and is briefed every mission; it is not a standing default under this paragraph.

(2) If, after canceling, the pilot subsequently requires IFR flight, the pilot must file a new IFR flight plan and must obtain an ATC clearance before operating in IFR conditions.

e. Automatic Closure at a Towered Airport.

(1) When the flight lands at an airport with a functioning control tower, the IFR flight plan closes automatically upon landing; the pilot does not need to cancel it by radio or through an FSS.

f. Cancellation at a Non-Towered Airport.

(1) When the flight lands at an airport without a functioning control tower, the pilot must initiate cancellation of the IFR flight plan; it does not close automatically.

(2) If an FSS or other means of direct communication with ATC is available after landing, the pilot may cancel the flight plan by that means.

(3) If no FSS or other direct means of communication with ATC is available after landing, or if two-way radio communication with ATC is not possible below the altitude at which coverage begins (an altitude that varies by location and is briefed every mission), the pilot should cancel the IFR flight plan by radio while still airborne and able to communicate with the facility, weather conditions permitting, using the call in b.(1) above.

Note: Canceling while still airborne under (3) above avoids the delay and expense of canceling by telephone after landing, and releases the airspace promptly for other traffic.

Table 1. IFR Flight Plan Closure Method by Airport Type

#	Airport Type	Closure Method	Pilot Action Required
1	Towered	Automatic on landing (e.(1))	None
2	Non-towered, FSS or direct ATC communication available after landing	Pilot-initiated after landing (f.(2))	Cancel with FSS or the facility by the available means
3	Non-towered, no FSS or communication available after landing, or no communication below the applicable altitude	Pilot-initiated while airborne (f.(3))	Cancel by radio before landing, weather permitting

Legend: FSS = Flight Service Station. ATC = Air Traffic Control.

Departure

This part establishes the sequence a pilot on an IFR flight plan follows from IFR clearance through release to Departure: obtaining the clearance before or during taxi, taxi and line-up-and-wait procedures, the abbreviated ("as filed") clearance form, and the obstacle-clearance and communication procedures tied to Obstacle Departure Procedures, Standard Instrument Departures, and Diverse Vector Areas.

Note: Several paragraphs in this part refer to "Clearance Delivery" as the facility that issues an IFR clearance before taxi. Throughout this part, Clearance Delivery means a dedicated Clearance Delivery frequency where the departure airport publishes one, or Ground, on the ground control frequency, where it does not. This convention is stated fully once, here and at paragraph 5.9, and is not restated in paragraphs 5.10, 5.12, and 5.14 below.

5.9 Pre-Taxi Clearance Procedures

This paragraph establishes the procedure by which a pilot filing an IFR departure may obtain the IFR clearance from Clearance Delivery before taxiing, at airports where a pre-taxi clearance program is published, and states the fallback procedure when that clearance is not obtained before the pilot is ready to taxi.

a. Where a pre-taxi clearance program is published for the departure airport, a pilot planning an IFR departure MAY obtain the IFR clearance from Clearance Delivery before taxiing, in place of receiving it from Ground or Tower later in the departure sequence.

Note: Clearance Delivery means a dedicated Clearance Delivery frequency where the airport publishes one, or Ground, at an airport without a separate Clearance Delivery position, performing this function on the ground control frequency. Paragraphs 5.10, 5.12, and 5.14 use this same convention without restating it.

b. Where a pilot elects to use the pre-taxi clearance program, the pilot WILL call Clearance Delivery not more than 10 minutes before the pilot's proposed taxi time. On that call, Clearance Delivery WILL issue the IFR clearance or, if the clearance is not yet available, delay information.

Example 1. Initial Pre-Taxi Clearance Call

Speaker	Transmission
PILOT	"Aeroville Clearance, November One Two Three Alpha Bravo, IFR to Example City, ready to copy."
CLEARANCE DELIVERY	"November One Two Three Alpha Bravo, Aeroville Clearance, cleared to Example City Airport as filed, climb and maintain three thousand, expect flight level two three zero, one zero minutes after departure, departure frequency one two six point one five, squawk four five one two."
PILOT	"Cleared to Example City as filed, climb and maintain three thousand, expect flight level two three zero, one zero minutes after departure, departure frequency one two six point one five, squawk four five one two, November One Two Three Alpha Bravo."

Callsigns, facility name, and all frequencies and codes above are generic placeholders for illustration only and are not asserted as real-world values.

c. When a pilot has received the IFR clearance from Clearance Delivery and is ready to taxi, the pilot WILL call Ground for taxi clearance.

Example 2. Ready-to-Taxi Call to Ground

Speaker	Transmission
PILOT	"Aeroville Ground, November One Two Three Alpha Bravo, ready to taxi, information Bravo."
GROUND	"November One Two Three Alpha Bravo, Aeroville Ground, taxi to runway two seven via Alpha, Alpha three."
PILOT	"Taxi to runway two seven via Alpha, Alpha three, November One Two Three Alpha Bravo."

d. Unless the departure airport's local procedure requires otherwise, a pilot MAY omit restating the IFR clearance or confirming its receipt on the ready-to-taxi call to Ground described in paragraph c. Where local procedure does require it, the pilot WILL state the required portion of the route, or confirm receipt of the clearance, per that facility's published procedure. Which airports require this restatement is briefed every mission; no simulator-wide default exists.

e. When a pilot is unable to establish contact with Clearance Delivery, or has not received the IFR clearance by the time the pilot is ready to taxi, the pilot SHOULD call Ground and inform the controller of the situation.

Example 3. Unable to Contact Clearance Delivery

Speaker	Transmission
PILOT	"Aeroville Ground, Raptor Two One, unable to contact Clearance Delivery, IFR to Example City, request clearance and taxi."
GROUND	"Raptor Two One, Aeroville Ground, standby for clearance."

f. Whether the pre-taxi clearance program described in this paragraph is in effect at a given airport is documented in that airport's published airport-information source (the real-world Chart Supplement, or the network's equivalent facility documentation).

Note: Where the network's own airport documentation differs from, or does not include, real-world Chart Supplement data for a given field, treat availability of the pre-taxi clearance program as briefed every mission. [VERIFY: confirm how this simulator network publishes pre-taxi clearance program availability per airport, if it differs from the real-world Chart Supplement.]

Note: This paragraph governs only the timing and call sequence for obtaining an IFR clearance before taxi. General Clearance Delivery, Ground, and taxi-clearance procedures not specific to the pre-taxi program are governed elsewhere in this contract.

5.10 Taxi Clearance

This paragraph establishes when a pilot operating on an IFR flight plan should first contact ground-handling ATC, and what that facility may provide in response. It does not cover VFR ground contact, taxi routing once underway, line-up-and-wait procedures, or the substantive content of an IFR clearance itself; those are governed elsewhere.

a. Prior to starting engines, each pilot operating on an IFR flight plan should contact the appropriate ground-handling facility for taxi instructions, the IFR clearance, and an engine start time.

 (1) At an airport with a published Clearance Delivery frequency, the pilot should call Clearance Delivery.

 (2) At an airport without a separate Clearance Delivery frequency, the pilot should call Ground on the published ground control frequency (paragraph 5.9).

Note: This is a SHOULD, not a MUST. Compliance is recommended and the pilot retains judgment, but a pilot who starts engines without making this call has not confirmed a taxi route, an IFR clearance, or an assigned engine start time in advance.

b. When contacted under a, Clearance Delivery or Ground (whichever the pilot called) will issue taxi instructions and, if applicable, the IFR clearance and an engine start time.

Note: [VERIFY: the source lists three items (engine start time, taxi instructions, IFR clearance) joined by "and/or," without stating which combination applies to a given contact.] Treat this as facility-dependent: the pilot receives whichever of the three the facility has to issue at that time, not all three as a standing rule. An engine start time specifically is issued only when the facility has assigned one (for example, under flow control); its absence from a given response is not an omission.

Example: IFR Pre-Engine-Start Contact

Pilot: "Springfield Clearance, Cessna Three Four Bravo, IFR to Example City Executive, request clearance."

Clearance Delivery: "Cessna Three Four Bravo, Springfield Clearance, cleared to Example City Executive as filed, climb via SID, maintain three thousand, expect flight level two two zero, one zero minutes after departure, departure frequency one two zero point four, squawk zero four five one, taxi to runway two three via Alpha, monitor Ground point niner."

Pilot: "Cleared to Example City Executive as filed, climb via SID, maintain three thousand, expect flight level two two zero, one zero minutes after departure, departure frequency one two zero point four, squawk zero four five one, taxi to runway two three via Alpha, monitor Ground point niner, Cessna Three Four Bravo."

Note: SID = Standard Instrument Departure. Callsign, airport names, runway, and frequencies above are generic placeholders for illustration and are not asserted as any real facility's published values.

Example: Contact With No Separate Clearance Delivery

Pilot: "Example County Ground, Skyhawk One Two Charlie, IFR to Example Metro, ready to copy clearance."

Ground: "Skyhawk One Two Charlie, Example County Ground, cleared to Example Metro as filed, maintain two thousand five hundred, expect four thousand, one zero minutes after departure, departure frequency one two five point six five, squawk zero two one four, taxi to runway one seven via Bravo."

Pilot: "Cleared to Example Metro as filed, maintain two thousand five hundred, expect four thousand, one zero minutes after departure, departure frequency one two five point six five, squawk zero two one four, taxi to runway one seven via Bravo, Skyhawk One Two Charlie."

Note: This example illustrates a field where Ground handles both taxi and clearance delivery instead of a separate Clearance Delivery position. This paragraph applies equally to general aviation, airline, and military IFR traffic; it states no distinction by operator category.

5.11 Line Up and Wait (LUAW)

This paragraph establishes the LINE UP AND WAIT (LUAW) instruction: the procedure Tower uses to position an aircraft on the departure runway to hold before takeoff clearance is issued, and the pilot and Tower actions and calls that follow. It applies to civil, air carrier, military, and formation traffic alike; no category of traffic is exempt. It does not establish takeoff clearance phraseology itself, or the post-departure frequency change to Departure, both established elsewhere in this chapter.

a. Definition and Effect

(1) LINE UP AND WAIT is the instruction Tower uses to position an aircraft onto the assigned departure runway, aligned with the departure direction, to hold there for further instructions.

(2) Each pilot must not begin a takeoff roll on the basis of a LINE UP AND WAIT instruction alone; a separate, explicit takeoff clearance from Tower is required before starting the roll.

Example: Line Up and Wait Instruction and Readback Tower: "Cessna Three Four Bravo, Runway Two Seven, Line Up and Wait." Pilot: "Runway Two Seven, Line Up and Wait, Cessna Three Four Bravo." Required response: The pilot reads back the runway and the instruction, including the aircraft's own call sign, as standard phraseology practice.

Call signs, facility names, and runway and frequency values in the examples throughout this paragraph are generic placeholders for illustration only and are not asserted as real-world or network-published values.

b. Takeoff Clearance Expectation

(1) When Tower has advised the pilot of the reason for the hold (for example, wake turbulence separation or traffic on an intersecting runway), or that reason is clearly visible to the pilot (for example, another aircraft still on the runway), and that reason has been resolved, each pilot should expect an imminent takeoff clearance.

(2) When Tower has instead advised the pilot of a delay, each pilot will continue to hold with no expectation of imminent clearance until Tower issues further instructions.

c. Delayed Takeoff Clearance

(1) When more than a brief interval passes after a LINE UP AND WAIT instruction with no takeoff clearance issued (discretion: no fixed interval is prescribed for this callback), each pilot should contact Tower to confirm status.

Note: FAA analysis of accidents and incidents involving aircraft holding in position found that 2 minutes or more elapsed, on average, between the LINE UP AND WAIT instruction and the resulting event (for example, a landing over the holding aircraft or a go-around). This finding explains why a prompt check-in matters; it does not establish a fixed callback interval.

Example: Delayed Clearance Query Pilot: "Aeroville Tower, Cessna Three Four Bravo, holding in position, Runway Two Seven." Tower: "Cessna Three Four Bravo, continue to hold, traffic is one mile final." Required response: Tower either confirms the continued hold, provides delay information, or issues the takeoff clearance.

d. Uncertainty and Query Procedure

(1) When a pilot is uncertain about any instruction or clearance received from Tower while holding under a LINE UP AND WAIT instruction, each pilot must contact Tower immediately to confirm it before taking further action.

Example: Uncertainty Query Pilot: "Aeroville Tower, Viper Two One, confirm that instruction was for Viper Two One?" Tower: "Viper Two One, negative, that instruction was for Cessna Three Four Bravo. Viper Two One, continue to hold." Required response: Tower confirms or corrects which aircraft the prior instruction addressed.

e. Frequency Discipline

(1) While holding in position under a LINE UP AND WAIT instruction, each pilot will monitor Tower's instructions and clearances issued to other aircraft on the frequency, including listening for call signs that sound similar to the pilot's own. Uncertainty about any such instruction is resolved under the query procedure established in paragraph d.

f. Runway Vigilance

(1) When conducting LUAW operations at night, during reduced visibility, or on a runway with intersecting-runway traffic, each pilot will scan the full length of the runway for aircraft crossing, on final approach, or landing, before taxiing onto the runway and while holding in position. A potential conflict identified during this scan is resolved under the query procedure established in paragraph d.

g. Multiple Active Runways

(1) When two or more runways are active for departures, Tower may issue LINE UP AND WAIT instructions to aircraft holding on more than one of those runways at the same time.

Note: During multiple-runway LUAW operations, the frequency-monitoring practice established in paragraph e and the takeoff-clearance confirmation duty established in paragraph h are especially important, because more than one aircraft may share the frequency with similar-sounding call signs at once.

h. Takeoff Clearance Confirmation

(1) When a pilot is not certain that a takeoff clearance applies to that pilot's own aircraft, such as during multiple-runway operations or when a similar-sounding call sign is on frequency, each pilot must confirm with Tower before beginning the takeoff roll.

Note: Tower prefers a confirmation call over a mistaken takeoff roll flown on another aircraft's clearance.

Example: Confirming Takeoff Clearance Pilot: "Aeroville Tower, confirm Skyhawk Four Tango Sierra is cleared for takeoff?" Tower: "Skyhawk Four Tango Sierra, negative, that clearance was for Skyhawk Four X-ray Sierra. Skyhawk Four Tango Sierra, continue to hold." Required response: Tower confirms or corrects which aircraft holds the takeoff clearance.

i. Intersection Departures

(1) When Tower issues a LINE UP AND WAIT instruction or a takeoff clearance from a runway intersection, Tower will include the intersection designator in the instruction.

(2) When Tower omits the intersection designator, each pilot must contact Tower for clarification before taxiing onto the runway.

Example: Intersection Line Up and Wait Tower: "Reach Three One, Runway Two Five Left at Bravo, Line Up and Wait." Pilot: "Runway Two Five Left at Bravo, Line Up and Wait, Reach Three One." Required response: The pilot reads back the runway, the intersection designator, and the instruction.

j. Traffic Advisories

(1) When landing traffic is a factor for a runway on which an aircraft is holding under a LINE UP AND WAIT instruction, Tower will advise the holding aircraft of the closest traffic within 6 flying miles requesting a full stop, touch-and-go, stop-and-go, or unrestricted low approach to that runway.

Example: Traffic Advisory While Holding Tower: "Cessna Three Four Bravo, holding in position, traffic four mile final, full stop." Pilot: "Cessna Three Four Bravo, holding, traffic in sight." Required response: No read back is required; the pilot should acknowledge receipt of the advisory.

k. Occupied Runway

(1) When a runway is occupied by another aircraft, each pilot on approach to that runway must not land, even after Tower has issued a landing clearance.

(2) When runway occupancy is in doubt, each pilot should query Tower without hesitation.

(3) Each pilot will be prepared to execute a go-around if the runway cannot be confirmed clear before landing.

Example: Occupied Runway Query Pilot: "Aeroville Tower, Example Air Twelve, confirm the runway is clear?" Tower: "Example Air Twelve, go around, traffic on the runway, fly runway heading, climb and maintain two thousand." Required response: Tower either confirms the runway is clear or instructs a go-around.

5.12 Abbreviated IFR Departure Clearance ("Cleared . . . As Filed")

a. Purpose. This paragraph establishes when the issuing facility may deliver an IFR departure clearance in abbreviated form rather than reading the complete filed route, and states what the pilot must do at the initial call-up to remain eligible for that abbreviated form instead of a full route clearance.

b. Scope. This paragraph governs the eligibility conditions and phraseology for the AS FILED clearance defined in paragraph c, and for the full route clearance issued in its place. It does not govern the content of Departure Procedures (DPs) themselves, established in paragraph 5.14, Instrument Departure Procedures, or clearance void times and lost-communication procedures, neither of which is covered by this contract.

c. Issuing facility and controlled terms. "Clearance Delivery" carries the meaning established at paragraph 5.9 for a pilot on the ground. For a pilot who has departed VFR and is requesting IFR clearance while airborne, it means Center (ARTCC) or the radar facility with jurisdiction over the pickup point. Example blocks below label the speaker with the specific facility working that scenario, not the generic term "Clearance Delivery." AS FILED refers to a clearance that states only the destination, any DP, and the altitude, without restating the filed route. FULL ROUTE refers to a clearance that states the complete route.

d. Eligibility and pilot notification. When the filed route can be approved with little or no revision, Clearance Delivery will issue the clearance AS FILED rather than reading the full route. This applies both to a pilot on the ground awaiting an IFR clearance and to a pilot who has departed VFR and is requesting IFR clearance while airborne.

 (1) If the pilot has changed the filed route or destination before departure, the pilot MUST NOT accept an AS FILED clearance for the original filed route.

 (2) At the initial call-up requesting clearance, the pilot MUST state whether the filed flight plan has been amended, or canceled and replaced with a new filed flight plan. If it has been amended or replaced, the pilot MUST request a full route clearance instead of AS FILED. If the flight plan has not changed, no additional notification is required beyond the standard initial call-up shown in the example below.

Note: The issuing facility may not yet have received a route or flight-plan amendment by the time the pilot calls for clearance. Stating the change at the initial call-up, rather than relying on the facility to notice it, is what keeps the pilot from being issued a clearance AS FILED against a route that no longer matches the flight plan on file.

EXAMPLE: Initial Call-Up, No Flight Plan Change PILOT: "Washington Clearance Delivery, American Seventy-Six, at gate one, IFR Los Angeles." CLEARANCE DELIVERY: Issues the clearance under paragraph d or e of this paragraph, as applicable.

EXAMPLE: Initial Call-Up, Flight Plan Changed PILOT: "Washington Clearance Delivery, American Seventy-Six, at gate one. IFR San Francisco. My flight plan route has been amended. Request full route clearance." CLEARANCE DELIVERY: Issues a full route clearance under paragraph e of this paragraph.

e. Full route clearance. When Clearance Delivery knows the filed flight plan has changed, or when the pilot requests a full route clearance, Clearance Delivery will issue a full route clearance stating the complete route instead of AS FILED.

f. Destination airport. Clearance Delivery will state the destination airport filed in the flight plan, whether the clearance is AS FILED or full route.

g. Departure procedure name. When a DP or DP transition is to be flown, Clearance Delivery MUST state the DP name, the current DP number, and the DP transition name, inserted after the phrase "cleared to [destination] airport" and before the phrase "then as filed." This applies to every departure clearance issued under this paragraph, whether or not the DP was filed in the flight plan.

h. STAR handling. A STAR filed in the flight plan is part of the filed route, and Clearance Delivery will not normally state it in the initial departure clearance. If the same ARTCC's airspace contains both the departure airport and the fix where the STAR or STAR transition begins, Clearance Delivery MAY state the STAR name, the current STAR number, and the STAR transition name in the initial clearance.

i. En route altitude. An AS FILED clearance does not by itself convey an en route altitude. Clearance Delivery will separately state an assigned en route altitude, or will advise the pilot to expect an assigned or filed altitude within a stated time or at a stated point after departure. Clearance Delivery may give this altitude information verbally in the departure instructions, or it may appear published in the DP.

Note: Altitudes in ATC phraseology are stated as bare numbers below Flight Level 180 (feet MSL implied) and as a flight level above Flight Level 180; the transmission itself does not include the word "feet."

j. Clearance phraseology. When issuing a departure clearance, Clearance Delivery will use one of the formats in (1) through (4), as applicable. In every case the pilot reads back the clearance in full, including any DP, transition, and assigned altitude, in accordance with this chapter's clearance-readback requirement.

Note: The examples in (1), (3), and (4) reproduce phraseology published in the source AIM. The example in (2) uses a generic placeholder airport, callsign, and frequency, since the source publishes no comparable transmission for that case, and is illustrative only, not an asserted official value.

 (1) Per the requirement in paragraph g, Clearance Delivery states the DP name, the current DP number, the DP transition name, the assigned altitude or flight level, and any further instructions the situation requires (departure frequency, transponder code, etc., at Clearance Delivery's discretion).

EXAMPLE: Clearance With Departure Procedure CLEARANCE DELIVERY: "National Seven Twenty, cleared to Miami airport, Intercontinental One departure, Lake Charles transition, then as filed, maintain flight level two seven zero."

 (2) When there is no DP, or the pilot cannot accept the DP that would otherwise apply, Clearance Delivery specifies the assigned altitude or flight level and any further instructions the situation requires, at Clearance Delivery's discretion, in place of the DP.

Note: Clearance Delivery MAY use a detailed departure route description or a radar vector, instead of a published DP, to achieve the desired routing.

EXAMPLE: Clearance Without Departure Procedure (illustrative) CLEARANCE DELIVERY: "Cessna Four Four Two Tango, cleared to Example Valley airport as filed, maintain four thousand, departure frequency one two five point one."

 (3) If a minor revision to the filed route is needed, Clearance Delivery specifies the assigned DP, DP transition, or departure routing, states the revision to the filed route, and states the assigned altitude or flight level and any further instructions the situation requires.

EXAMPLE: Clearance With a Minor Route Revision CLEARANCE DELIVERY: "Jetstar One Four Two Four, cleared to Atlanta airport, South Boston Two departure, then as filed except change route to read South Boston, Victor Two Zero, Greensboro, maintain one seven thousand."

 (4) In a nonradar environment, Clearance Delivery additionally specifies one or more fixes needed to identify the initial route of flight.

EXAMPLE: Clearance in a Nonradar Environment CLEARANCE DELIVERY: "Cessna Three One Six Zero Foxtrot, cleared to Charlotte airport as filed via Brooke, maintain seven thousand."

Note: A nonradar clearance format applies only where the departure sector has no radar coverage. Where it does, (1) through (3) apply instead.

k. Pilot practice. To keep an AS FILED clearance available, the pilot SHOULD avoid changing the filed flight plan just before departure. When requesting an airborne IFR pickup after departing VFR, the pilot SHOULD call Center with enough lead time before the fix where IFR operations are to begin to avoid delay; no standard lead time is published, and the amount of notice needed is at the pilot's discretion based on traffic and workload.

EXAMPLE: Airborne VFR-to-IFR Pickup Request PILOT: "Los Angeles Center, Apache Six One Papa, VFR estimating Paso Robles VOR (VHF Omnidirectional Range) at three two, one thousand five hundred, request IFR to Bakersfield." CENTER: Issues an IFR clearance under paragraphs d through j of this paragraph, as applicable, or advises the pilot of expected delay.

l. Clarification. If any portion of a clearance received is not clearly understood, the pilot MUST request verification or clarification from Clearance Delivery before executing it.

5.13 Departure Control

This paragraph establishes Departure's role in separating departing aircraft after Tower releases them, the initial-heading and RNAV SID advisories the departure-clearance facility issues before that release, and the departure frequency and transponder/Automatic Dependent Surveillance-Broadcast (ADS-B) procedures that connect the two. It applies to civil, air carrier, military, and formation departures alike; no category of traffic is exempt. It does not establish initial IFR clearance delivery, takeoff clearance phraseology, or lost-communication procedures, all established elsewhere in this chapter.

a. Function

(1) Once Tower releases a departing aircraft, Departure will assume responsibility for separating that aircraft from other departures until it leaves the terminal area or is handed off to the next facility.

Note: "A departure," lower case, means a departing aircraft or flight in the paragraphs below. "Departure," capitalized, means the facility itself.

b. Runway Selection

(1) Departure may recommend that Tower assign a takeoff runway or departure direction other than the one otherwise active, to reduce turns needed after takeoff to reach the assigned route or to support local noise-abatement or congested-area-avoidance procedures; Tower retains runway-assignment authority.

c. Departure-Clearance Facility

(1) In the paragraphs below, "the departure-clearance facility" stands for whichever facility actually issues the initial-heading and RNAV SID advisories described in paragraphs d and e. This extends the Clearance-Delivery-or-Ground convention established at paragraph 5.9 to include Tower: Clearance Delivery where the airport has a separate clearance-delivery position, or Ground or Tower where it does not. Which facility performs this function at a given airport is briefed every mission; no simulator-wide default exists. Example blocks below label the speaker with the specific facility working that scenario, not this generic term.

Note: [VERIFY: confirm how this simulator network documents, per airport, which facility performs the departure-clearance function described in this paragraph, if that assignment is not otherwise evident from the network's facility roster for the airport in use.]

d. Initial Heading Assignment

(1) When a departure will be vectored immediately after takeoff, using vectors, a Diverse Vector Area (DVA), or a published Departure Procedure (DP) that begins with an ATC-assigned heading off the ground, the departure-clearance facility will advise the pilot of the initial heading before takeoff.

(2) The departure-clearance facility may omit the reason for that heading.

(3) When the assigned heading takes the aircraft off a published procedure that includes a lateral path and altitude restrictions (for example, an RNAV SID with crossing restrictions from the departure runway), the departure-clearance facility must assign an altitude to maintain with the initial heading.

(4) When a speed restriction is also needed to maintain separation from the published procedure, the departure-clearance facility must assign a speed to maintain, in addition to the altitude required by (3).

Note: This altitude assignment matters because, once vectored off the published lateral path, the aircraft no longer has the SID's own altitude and obstacle-clearance restrictions in effect; the assigned altitude substitutes for them until the aircraft rejoins the procedure or receives further instructions.

Example: Initial Heading Assignment (illustrative) TOWER: "Speedbird One Two, turn left heading two five zero after departure, Runway Two Six Left, cleared for takeoff." Required response: No read back is required beyond standard clearance acknowledgment; the pilot complies by flying the assigned heading after takeoff.

Note: This heading may instead be issued earlier, as part of the initial IFR clearance from the departure-clearance facility under paragraph c, depending on local procedure.

Call signs, facility names, and frequency, heading, and code values in the examples throughout this paragraph are generic placeholders for illustration only and are not asserted as real-world or network-published values.

e. RNAV SID Advisory

(1) At some airports, when a departure will fly an RNAV SID that begins at the runway, the departure-clearance facility may advise the aircraft of the initial fix or waypoint on the RNAV route.

Note: This advisory exists to prompt the pilot to verify that the correct RNAV SID is programmed in the FMS (Flight Management System) before takeoff.

(2) When a pilot discovers a different RNAV SID entered in the aircraft's FMS, each pilot must immediately advise the departure-clearance facility of the discrepancy.

(3) When the departure-clearance facility does not issue this advisory, each pilot must fly the assigned SID as published; the absence of an advisory does not relieve the pilot of that duty.

Example: RNAV SID Takeoff Clearance (documented AIM phraseology) TOWER: "Delta Three Four Five, RNAV to MPASS, Runway Two Six Left, cleared for takeoff." Required response: No read back is required beyond standard clearance acknowledgment; the pilot complies by flying the cleared departure.

Note: The SID transition is not restated in the takeoff clearance because it is already contained in the pilot's IFR clearance.

Note: An RNAV SID designed to begin with a vector to the initial waypoint is issued together with an assigned heading before departure, under paragraph d.

Example: FMS Discrepancy Report (illustrative) PILOT: "Aeroville Clearance, November Four Two Bravo, we have the Example Two RNAV departure loaded, not the Example Three." CLEARANCE DELIVERY: "November Four Two Bravo, roger, standby for an amended clearance." Required response: The departure-clearance facility corrects or reissues the clearance before releasing the aircraft for taxi or takeoff.

f. Off-Route Vectoring

(1) When Departure vectors an aircraft off a previously assigned nonradar route, Departure will advise the pilot briefly what the vector is intended to achieve.

(2) Following that vector, Departure will continue radar service until the aircraft is reestablished on course, using an appropriate navigation aid, and Departure has advised the pilot of the aircraft's position, or until a handoff is made to Approach or Center, as applicable, with further surveillance capability.

g. Departure Frequency Assignment

(1) Before takeoff, the departure-clearance facility or Tower will inform the pilot of the departure control frequency and, if appropriate, the transponder code.

(2) When a DP has been or will be assigned and the departure control frequency is published on that DP, the departure-clearance facility or Tower may omit stating the departure control frequency verbally in place of (1).

(3) Until Tower instructs the frequency change, each pilot should not switch to the departure control frequency; the timing of that instruction is at Tower's discretion (no fixed altitude or distance is published for it).

Example: Departure Frequency Handoff (illustrative) TOWER: "Speedbird One Two, contact Departure, One Two Five Point Three Five." PILOT: "One Two Five Point Three Five, Speedbird One Two." Required response: The pilot checks in with Departure on the new frequency using standard call-up phraseology after switching.

h. Transponder and ADS-B Operation

(1) As soon as practical after receiving the assigned transponder code, each pilot must adjust the transponder and ADS-B to the "on" or normal operating position.

(2) Once set, each pilot must keep the transponder and ADS-B in that position throughout the flight, unless Departure requests a change to "standby."

5.14 Instrument Departure Procedures

Purpose. This paragraph establishes obstacle-clearance criteria and radio-communication procedures for IFR departures flown under an Obstacle Departure Procedure (ODP), a Standard Instrument Departure (SID), a Diverse Vector Area (DVA), or a Visual Climb Over Airport (VCOA) option, and states which facility in the departure handoff chain (Clearance Delivery, Ground, Tower, or Departure) issues each associated call.

Note: "Departure," capitalized, denotes the Departure control facility (the radar position working outbound traffic after Tower releases it). Lowercase "departure" denotes the flight event or the published procedure. Both recur throughout this paragraph.

a. Definitions and Departure Procedure Types

A departure procedure (DP) is a preplanned IFR procedure that provides obstacle clearance from the departure airport to the en route structure. Two types exist:

(1) An Obstacle Departure Procedure (ODP) is printed either textually or graphically and provides obstacle clearance. It does not require ATC authorization to fly. Where no SID or DVA is assigned, the pilot and ATC treat the ODP published for that airport as in effect for the departure.

(2) A Standard Instrument Departure (SID) is always printed graphically and is designed to increase efficiency and reduce communication. Clearance Delivery (paragraph 5.9) will assign a SID as part of the departure clearance.

Either type may be built to conventional or RNAV criteria and assumes normal aircraft performance with all engines operating.

b. Diverse Vector Area

A Diverse Vector Area (DVA) is an area, established to the United States Standard for Terminal Instrument Procedures (TERPS) diverse-departure criteria, in which Departure or Tower may assign random radar headings during an uninterrupted climb from the departure runway until the aircraft is above the minimum vectoring altitude or minimum IFR altitude (MVA/MIA). A DVA provides obstacle and terrain clearance in place of an ODP or SID and, where published, is the default method of obstacle clearance for radar-vectored departures at that airport.

c. Recommended Use of Departure Procedures

When an ODP is published for the departure airport and no SID or DVA is assigned, each pilot operating under 14 CFR Part 91 should file and fly the ODP at night and during marginal visual meteorological conditions (VMC) or instrument meteorological conditions (IMC).

d. Obstacle Clearance Criteria

(1) Standard climb gradient. Unless a higher gradient is published or an ATC crossing restriction requires otherwise, obstacle clearance on departure assumes the aircraft crosses the departure end of runway (DER) at least 35 feet above DER elevation, climbs to 400 feet above DER elevation before making the first turn, and maintains a climb gradient of at least 200 feet per nautical mile (FPNM) to the minimum IFR altitude for the route.

(2) Engine-out and other contingencies. ODPs, SIDs, and DVAs assume all engines operating; none accounts for an engine failure or other in-flight emergency after takeoff. Contingency procedures for that case are briefed every mission; the operator, not the published procedure, is responsible for developing them.

(3) Obstacle Identification Surface (OIS). The 40:1 OIS begins at the DER and slopes upward at 152 FPNM until it reaches the minimum IFR altitude or the aircraft enters the en route structure. An obstacle penetrating this surface is charted as a takeoff obstacle note under (4).

(4) Takeoff obstacle notes. An obstacle penetrating the 40:1 OIS is published as a takeoff obstacle note in the airport's Takeoff Minimums and (Obstacle) Departure Procedures entry in the Terminal Procedures Publication (TPP), in one of two categories.

(a) A low, close-in obstacle lies 1 NM or less from the DER and 200 feet or less above DER elevation. It does not raise the published takeoff minimums.

(b) A takeoff minimums obstacle lies 2.6 NM or less from the DER and more than 200 feet above DER elevation. It does raise the published takeoff minimums.

(c) Where published, a DER crossing altitude states the height that clears every obstacle penetrating the 40:1 OIS for that runway, letting a pilot correlate a charted obstacle's position with the altitude needed to overfly it. See Table 1.

Table 1. Takeoff Obstacle Note Categories

Category	Distance from DER	Height Above DER Elevation	Effect on Takeoff Minimums
Low, close-in obstacle	1 NM or less	200 ft or less	None
Takeoff minimums obstacle	2.6 NM or less	Greater than 200 ft	Increased

Legend: DER = departure end of runway; NM = nautical mile; ft = feet.

(5) Nonstandard climb gradients. When a climb gradient greater than 200 FPNM is published for a procedure and that procedure is part of the pilot's ATC clearance, the pilot must maintain the published gradient until reaching the altitude or fix at which it terminates, then at least 200 FPNM to the minimum IFR altitude for the route.

(6) Visual Climb Over Airport (VCOA). A VCOA is a departure option, published on some ODPs, that lets a pilot climb visually over the airport to a published "at or above" altitude before proceeding on an instrument routing.

(a) A published VCOA is available only when the ceiling and visibility at departure equal or exceed the minimums published for it; otherwise, the pilot flies the ODP, SID, or DVA assigned instead. To fly a published VCOA, the pilot will advise Clearance Delivery (paragraph 5.9) as early as possible before departure of the intent to fly it.

(b) During the visual climbing turns, the pilot must remain within the distance from the airport defined by the visibility minimum published for that VCOA, maintaining a climb gradient of at least 200 FPNM.

(c) On reaching the published "at or above" altitude, the pilot may proceed either on a diverse instrument departure or on the routing published for the VCOA, including a holding pattern where one is charted, to reach the minimum en route or minimum IFR altitude.

e. Obstacle Clearance Responsibility

(1) When a pilot operating under Part 91 departs IFR without an assigned ODP, SID, or DVA heading, the pilot bears full responsibility for obstacle clearance using standard takeoff minimums: 1 statute mile (SM) visibility for a single- or twin-engine aircraft, 1/2 SM for an aircraft with more than two engines (14 CFR §91.175).

(2) When a pilot is cleared for an ODP, SID, VCOA, or DVA, the pilot must comply with the published takeoff minimums and takeoff obstacle notes for the runway used, established in d.(4) above.

(3) On a VCOA, obstacle clearance is not guaranteed if the pilot maneuvers beyond the published visibility minimum before reaching the published altitude; the pilot remains responsible for clearance from any low, close-in obstacle throughout the visual climb.

(4) On a DVA, the pilot remains responsible for clearance from any low, close-in obstacle; where a DVA specifies a climb gradient greater than 200 FPNM, d.(5) applies.

Note: The climb-gradient continuity established in d.(1) and d.(5) applies regardless of which departure method (ODP, SID, VCOA, or DVA) the pilot is using.

f. Departure Procedure Publication

Textual ODPs, graphic ODPs, and SIDs for an airport are published in that airport's Takeoff Minimums and (Obstacle) Departure Procedures entry (TPP Section C) or as a separately charted graphic procedure (TPP Section L), indexed by airport and runway. A graphic ODP carries "(OBSTACLE)" in its procedure title to distinguish it from a SID. An instrument approach or departure chart marked with a "T" symbol directs the pilot to the airport's TPP Section C entry for takeoff minimums and obstacle information. Takeoff minimums and climb gradients published in Section C apply to every departure from that runway, including a radar-vectored departure, unless the charted procedure being flown states otherwise.

g. Departure Clearance and In-Flight Compliance

(1) Before an IFR departure, each pilot should review the terrain and obstacles near the departure airport, confirm whether an ODP is published, review the runway's takeoff obstacle notes established in d.(4), and, where a DVA is published, confirm the aircraft can meet the DVA's climb gradient. If the aircraft cannot meet a published nonstandard climb gradient, the pilot must advise ATC before departure; otherwise, no separate notification is required.

(2) When flying a SID with a published speed restriction at a waypoint, the pilot must not exceed that speed before reaching the waypoint.

(3) When Departure vectors a pilot off a published SID route, or clears a deviation from it, without stating "expect to resume [SID name]," that vector or deviation cancels every published altitude and speed restriction on the SID; Departure will issue replacement altitude instructions, and replacement speed instructions if the canceled SID published one. When Departure instead states "expect to resume [SID name]" while vectoring the pilot off the route, Departure will reclear the pilot onto the SID at a downstream fix, established in (4).

(4) When resuming a SID under (3), Departure will either reissue each remaining published altitude and speed restriction individually or reclear the pilot to "climb via [SID name]."

(5) When a SID has no published crossing restrictions, includes a radar-vector segment, or is entirely radar-vectored, Clearance Delivery (or Departure, if the clearance is amended after departure) will issue the applicable altitude using "maintain [altitude]" phraseology rather than "climb via."

(6) When a pilot's clearance contains "climb via [SID name]," the pilot must join or resume the procedure's lateral path and comply with every published or ATC-assigned altitude and speed restriction on it. Where the pilot was previously assigned an altitude lower than the next waypoint's published altitude, the pilot may climb at their own discretion to that published altitude.

(7) The top altitude of a "climb via" clearance is the highest altitude published on the procedure, or a different altitude if ATC assigns one; it is the upper limit of the climb authorized under (6).

(8) When a SID waypoint has no published altitude and the pilot is joining or resuming the procedure at that waypoint, Departure will assign a crossing altitude.

(9) On initial contact with Departure after departing on a "climb via" clearance, the pilot will state the altitude the aircraft is leaving and any ATC-assigned restriction that differs from the charted procedure.

(10) When Departure issues an altitude clearance, before or after departure, to a pilot cleared to climb via a published procedure, that clearance cancels every altitude restriction previously issued for that procedure, whether ATC-assigned or charted. Published lateral-path and speed restrictions on the procedure remain in effect unless Departure explicitly cancels them.

(11) ATC must not delete or modify an altitude or speed restriction published on an ODP.

Note: The ODP restriction in (11) is load-bearing rather than advisory: it is the obstacle clearance established in d.(1) through d.(5), not a routing convenience, so ATC has no discretion to waive or amend it.

h. Performance-Based Navigation Departure Procedures

(1) A public Performance-Based Navigation (PBN) SID or graphic ODP in the National Airspace System is normally built to the RNAV 1, Required Navigation Performance (RNP) 1, or Advanced RNP (A-RNP) navigation specification, typically beginning with an initial track or heading segment near the DER. Each pilot flying an RNAV 1 or RNP 1 procedure must keep total system error within 1 NM for 95 percent of the flight time on the procedure; for an A-RNP procedure, the minimum required navigation performance value is published in the procedure's PBN information box.

(2) Where a procedure has PBN elements, its chart carries a PBN information box stating the navigation specification, any required sensor or ground infrastructure, any required additional function, the minimum RNP value, and any other applicable condition. Every item in that box is a requirement for flying the procedure's PBN elements.

Note: Illustrative callsigns, fix names, headings, altitudes, and frequencies in the examples below are generic placeholders. They are not official published data for any real airport, route, or facility.

EXAMPLE — SID Clearance from Clearance Delivery

CLEARANCE DELIVERY: "November One Two Three Alpha Bravo, cleared to Example Airport as filed, ROBUC TWO departure, climb via SID except maintain five thousand, expect flight level two three zero one zero minutes after departure, departure frequency one two five point three five, squawk zero four five one."
PILOT: "Cleared to Example Airport as filed, ROBUC TWO departure, climb via SID except maintain five thousand, expect flight level two three zero one zero minutes after departure, departure frequency one two five point three five, squawk zero four five one, November One Two Three Alpha Bravo."

EXAMPLE — Initial Contact Report on a Climb Via Clearance

PILOT: "Example Departure, Jetlink Four Four Zero Zero, climbing via the ROBUC TWO departure, leaving three thousand for five thousand."
DEPARTURE: "Jetlink Four Four Zero Zero, Example Departure, radar contact, climb via SID."

EXAMPLE — Vector Off a SID With Expect-to-Resume

DEPARTURE: "Viper Two One, fly heading three three zero, vectors for traffic, expect to resume the ROBUC TWO departure."
PILOT: "Fly heading three three zero, expect to resume the ROBUC TWO departure, Viper Two One."
(later)
DEPARTURE: "Viper Two One, five miles from ROBUC, cross ROBUC at or above one two thousand, resume the ROBUC TWO departure."
PILOT: "Cross ROBUC at or above one two thousand, resume the ROBUC TWO departure, Viper Two One."

EXAMPLE — Radar Vectors in a Diverse Vector Area

TOWER: "Cessna Four Alpha Bravo, Runway Two Four, fly runway heading, cleared for takeoff."
DEPARTURE: "Cessna Four Alpha Bravo, Example Departure, radar contact, fly heading two seven zero, climb and maintain four thousand."

Note: Departure and Tower are not required to announce a Diverse Vector Area by name; a DVA vector is issued as an ordinary heading assignment, established in b. above.

EXAMPLE — VCOA Request and Approval

PILOT: "Clearance Delivery, November One Two Three Alpha Bravo, request the visual climb over the airport on the Example Six departure."
CLEARANCE DELIVERY: "November One Two Three Alpha Bravo, roger, cleared to Example Airport as filed via the Example Six departure, visual climb over the airport approved, maintain visual and climb to at or above five thousand five hundred before proceeding on course, departure frequency one two zero point niner, squawk zero five five two."

Note: The 300 feet ceiling and 1 NM visibility figure sometimes cited for visually acquiring and avoiding a low, close-in obstacle is illustrative only, tied to that obstacle's charted position and height. No fixed weather minimum applies; the assessment is at discretion of the pilot, per e.(1).

Note: This paragraph applies without regard to operation category. Military, formation, general aviation, and air carrier IFR departures all fly ODPs, SIDs, DVAs, and VCOAs under the same criteria and communication procedures established above; the source material draws no distinction among them.

Note: A "climb via" clearance authorizes lateral and vertical navigation of the procedure; it does not by itself authorize a speed change. Published or ATC-assigned speed restrictions on the procedure remain in effect until Departure cancels them, established in g.(10).

This paragraph does not establish an airport's published takeoff minimums, weather minimums, or runway-specific obstacle data (established in that airport's TPP Takeoff Minimums and (Obstacle) Departure Procedures entry, per f. above). It does not establish general IFR clearance delivery, read-back, or flight-plan-filing procedures, arrival or approach procedures, or ATC separation standards; those are established elsewhere in this contract.

En Route

This part establishes communication, reporting, route-selection, and holding procedures for the en route segment of a flight: Center's direct-communication and frequency procedures, the position and additional reports a pilot gives without being asked, the fixed route systems a pilot files and flies, course-change technique, and holding.

5.15 ARTCC (Center) Communications

a. Purpose. This paragraph establishes how Center communicates with an aircraft on the en route network segment: the direct-communication capability Center provides, the phraseology Center and the pilot use to change frequency and to establish initial contact, the phraseology Center uses to verify an aircraft's altitude, the procedure a pilot follows when a Center frequency appears to have failed, and the data-link equipage requirement for the Oakland and New York Oceanic Flight Information Regions (FIRs).

b. Scope. This paragraph governs communications between Center and an aircraft operating on an IFR flight plan, or otherwise receiving IFR services, in the en route environment. It does not govern the content or timing of a position report itself, established in paragraph 5.16, Position Reporting; the procedure a pilot follows after a complete loss of two-way radio communication, established in the source AIM's Chapter 6, Two-Way Radio Communications Failure, which is not adapted into this contract; or the individual CPDLC (Controller-Pilot Data Link Communications) uplink and downlink message texts, which this paragraph does not catalog (paragraph e, Note).

c. Controlled terms. "Center" means the ARTCC (Air Route Traffic Control Center) sector working the aircraft, reached through an RCAG (Remote Center Air/Ground) site on the sector's assigned frequency. "Transferring controller" means the Center sector the aircraft is leaving; "receiving controller" means the Center sector, or other facility, the aircraft is changing to. "FSS" carries the meaning established in the Glossary.

d. Direct communication and frequency use. While operating on an IFR flight plan within Center's area, Center will maintain direct two-way communication with the aircraft on the discrete VHF (Very High Frequency) or UHF (Ultra High Frequency) frequency assigned to the sector currently working it. Each Center sector uses its own discrete frequency; a military aircraft is worked on a UHF frequency where the sector publishes one.

 (1) When a pilot needs flight-plan filing, en route weather, or similar information not related to air traffic control, the pilot SHOULD direct that request to FSS, company communications, or the applicable military facility, rather than to Center on the sector's control frequency.

e. Data-link supplement (CPDLC). When an aircraft is equipped for CPDLC, Center MAY work it via data link in addition to voice; voice remains the primary and controlling means of communication. Center's CPDLC uplink categories include altimeter-setting messages, transfer-of-communications messages, initial-contact altitude validation, route and airborne-reroute assignments, altitude and speed assignments, crossing constraints, holding instructions, and advisory or emergency messages.

Note: Whether this network's ATC and pilot clients support a CPDLC-equivalent data-link exchange, and the logon address or procedure to use, is set by the network, not by this document; confirm current capability through the network's own published documentation before relying on it. The individual uplink and downlink message texts, published in the source document as a numbered table series, are outside this paragraph's scope and are not reproduced here.

f. Frequency change instruction. When Center determines the aircraft is to change frequency, the transferring controller issues the instruction in the form of the example below. The pilot will continue to monitor the transferring controller's frequency until the time, fix, or altitude stated in the instruction. The pilot will then call the receiving controller using the format in Table 1.

EXAMPLE: Frequency Change Instruction TRANSFERRING CONTROLLER: "Speedbird Four Niner Two, contact Denver Center one three three point five at PILOX."

g. Initial contact format. On first contact with a receiving Center sector, the pilot will state the elements in Table 1 for the applicable environment. The pilot MUST state the altitude or flight level to the nearest 100-foot increment.

Table 1: Initial Contact Report Format

Environment	Pilot States
Radar, level flight	Facility name, aircraft identification, LEVEL (altitude or flight level)
Radar, climbing or descending	Facility name, aircraft identification, LEAVING (exact altitude or flight level), CLIMBING TO or DESCENDING TO (assigned altitude or flight level)
Nonradar	Facility name, aircraft identification, position, altitude, ESTIMATING (next reporting point) AT (time)

Legend: LEVEL, LEAVING, CLIMBING TO, DESCENDING TO, and ESTIMATING are brevity terms spoken in the order shown, in place of the parenthetical they precede.

Note: Center uses the reported altitude to validate the aircraft's Mode C (automatic altitude-reporting transponder) return before relying on it for separation.

EXAMPLE: Initial Contact, Radar, Level Flight PILOT: "Denver Center, Speedbird Four Niner Two, level three seven zero."

EXAMPLE: Initial Contact, Radar, Descending PILOT: "Denver Center, Speedbird Four Niner Two, leaving flight level three seven zero, descending to flight level two four zero."

EXAMPLE: Initial Contact, Nonradar PILOT: "Anchorage Center, Arctic One One, over Sparrevohn, one one thousand, estimating Farewell at three five."

Note: The content and cadence of position reports after initial contact are established in paragraph 5.16, Position Reporting; this paragraph governs only the initial-contact format.

h. Altitude verification. When Center needs to confirm an aircraft's altitude, Center states VERIFY AT (altitude) for an aircraft in level flight, or VERIFY ASSIGNED ALTITUDE AS (altitude) for an aircraft climbing or descending. The pilot then MUST confirm the stated altitude if it is correct, or state the actual altitude being maintained, or the different assigned altitude, if the controller's statement is incorrect.

EXAMPLE: Altitude Verification CENTER: "Arctic One One, verify assigned altitude as one one thousand." PILOT: "Arctic One One, assigned one one thousand, correct."

i. Center frequency outage. When a pilot cannot raise Center on the assigned frequency, the pilot follows (1) through (4), in order, to reestablish contact.

 (1) The pilot SHOULD wait at least 60 seconds before concluding the frequency itself has failed.

Note: Center's backup receiver/transmitter for a frequency normally restores service within 60 seconds of a failure; the wait lets that backup take effect before the pilot moves to (2).

 (2) If the failure occurred at the time of a frequency change, the pilot will attempt to recontact the transferring controller on the prior frequency for an alternate frequency.

 (3) If the failure occurred after contact was already established on the current frequency, the pilot will try another Center frequency, giving priority to the next sector expected to work the aircraft.

 (4) If (2) and (3) do not reestablish contact, the pilot MAY contact FSS for instructions.

Note: This paragraph addresses a Center equipment or frequency outage only. It does not restate the procedure for a complete two-way radio communications failure, established in the source AIM's Chapter 6, Two-Way Radio Communications Failure, which is not adapted into this contract.

EXAMPLE: Reestablishing Contact After a Frequency Outage PILOT (on prior frequency): "Denver Center, Speedbird Four Niner Two, no contact one three three point five, request alternate frequency." TRANSFERRING CONTROLLER: "Speedbird Four Niner Two, Denver Center, try one two eight point four five."

j. Oceanic data-link equipage (Oakland and New York FIRs). Within the Oakland Oceanic FIR (KZAK) or the New York Oceanic FIR (KZWY), CPDLC and ADS-C (Automatic Dependent Surveillance-Contract) use is permitted only for an aircraft equipped through Inmarsat or Iridium. The pilot MUST include the corresponding code from Table 2 in Item 10a of the ICAO (International Civil Aviation Organization) flight plan. If neither code is filed, the FIR's data-link system will reject the logon and the aircraft will not connect.

Table 2: Oceanic Data-Link Provider Codes (ICAO FPL Item 10a)

Provider	Code	Applies In
Inmarsat	J5	KZAK, KZWY
Iridium	J7	KZAK, KZWY

Legend: FPL = Flight Plan; KZAK = Oakland Oceanic FIR; KZWY = New York Oceanic FIR.

Note: Whether this network's oceanic sectors implement CPDLC/ADS-C logon at all, and by what means, is at the network's discretion and not standardized here. Where a mission briefs oceanic data-link operations, the equipment code to file is briefed as part of that mission.

5.16 Position Reporting

This paragraph establishes when a pilot transmits an en route position report without being asked, when Center or Approach Control instead requests one, how a pilot times a report against the fix being reported, and the eight items every position report contains. It applies to civil, military, formation, and airline traffic operating on a filed route alike; no category of traffic is exempt. It does not establish flight-plan filing itself, lost-communication procedures (a topic of the source AIM's Chapter 6, Two-Way Radio Communications Failure, not adapted into this contract), or the additional in-flight reports required beyond a position report (for example, a report of hazardous weather or an unforecast condition), established in paragraph 5.17, Additional Reports.

a. Fix-Passage Timing

(1) When passing a VOR (VHF Omnidirectional Range) facility for a position report, the pilot will treat the fix-passage time as the moment the TO/FROM indicator completes its first full reversal.

(2) When passing an ADF (Automatic Direction Finder) facility for a position report, the pilot will treat the fix-passage time as the moment the bearing indicator completes its reversal.

(3) When a position report is keyed to an aural or light-panel signal (for example, a marker beacon), the pilot will note the time the signal begins and the time it ends. The pilot will then treat the fix-passage time as the mean (midpoint) of those two times.

(4) When a reported position is defined by distance and direction from a facility rather than by direct station passage, the pilot will compute the distance and direction as accurately as the aircraft's equipment permits (discretion: no numeric tolerance is published; precision is bounded by the aircraft's installed equipment, not by a stated figure).

(5) Except while transitioning through a terminal area, Center, Approach Control, or Departure will not require a position report keyed to a navigation aid that is not established for the route or airspace structure being flown.

Note: (5) limits what Center, Approach Control, or Departure may demand; it does not limit what a pilot may volunteer. A pilot may still reference an off-structure aid in a remark under paragraph d(8).

b. Reporting-Point Symbols

(1) At a reporting point charted with the solid-triangle symbol in Table 1 (a compulsory reporting point), the pilot will transmit a position report without being asked.

(2) At a reporting point charted with the open-triangle symbol in Table 1 (an on-request reporting point), the pilot will transmit a position report only when Center or Approach Control specifically requests it; otherwise, no report is required at that point.

Table 1. En Route Chart Reporting-Point Symbols

Item	Symbol	Point Type	Report Without Being Asked?
1	Solid triangle	Compulsory reporting point	Yes
2	Open (hollow) triangle	On-request reporting point	No; only when requested

Example: On-Request Point Call Center: "Reach Three One, report Danby Intersection." Pilot: "Wilco, Reach Three One." (The pilot then transmits the full position report established in paragraph d when reaching Danby Intersection.) Required response: The pilot acknowledges the request and transmits the position report under paragraph d at the named point; no report is due at that point absent the request.

c. Reporting Requirement by Environment

(1) On an airway or a published route, the pilot will transmit a position report, without being asked, over each compulsory reporting point along the route being flown, regardless of altitude.

(2) On a direct (non-airway) route, the pilot will transmit a position report, without being asked, over each reporting point used in the flight plan to define the route of flight.

(3) Once Center or Approach Control advises the pilot "radar contact," the pilot will discontinue the position reports required under (1) and (2) above. When Center or Approach Control instead advises "radar contact lost" or "radar service terminated," the pilot will resume the position reports required under (1) and (2) above.

Note: Center or Approach Control advises "radar contact" at two points: when the aircraft is first identified in the radar system, and again if radar identification is reestablished after radar service was terminated or radar contact was lost. A pilot who has not heard either call has not been told to discontinue reporting.

Example: Radar Contact Established, Then Lost Center: "Trans Air Twelve, Great Lakes Center, radar contact, one two miles west of Example VOR." Pilot: "Trans Air Twelve." (Trans Air Twelve now discontinues position reports under (3) above.) Center: "Trans Air Twelve, radar contact lost, resume normal position reporting." Pilot: "Trans Air Twelve, wilco, next report Fenton." Required response: No read back is required for either call; the pilot's next action (discontinuing or resuming reports) is the response.

(4) In an oceanic or other nonradar environment, the pilot must transmit a position report over each point used in the flight plan to define the route of flight, including a point charted as an on-request reporting point under paragraph b. When the aircraft provides automatic position reporting through an ADS-C (Automatic Dependent Surveillance-Contract) logon, the pilot should discontinue voice position reports.

Note: (4) is written as must, not will, because separation in an oceanic or other nonradar environment depends on the position reports themselves; there is no radar backup if a report is missed.

d. Report Content

When a position report is due under paragraph b or c, the pilot will include the following items, in order:

(1) Identification: the pilot's call sign.

(2) Position: the reporting point, fix, or waypoint being reported, stated by name or, on a route defined by coordinates, by the coordinate fix.

(3) Time: the fix-passage time computed under paragraph a.

(4) Altitude or flight level: the aircraft's current altitude or flight level. When operating under a VFR-on-top clearance, the pilot will state the actual altitude or flight level flown, not the phrase "VFR-on-top" alone. (VFR-on-top clearance procedures are established in paragraph 4.35, VFR-on-Top and VFR Conditions Authorizations.)

(5) Type of flight plan: "IFR" or "VFR." When the report is IFR and transmitted directly to Center or Approach Control, the pilot may omit this item.

Note: The omission in (5) is permitted because Center and Approach Control already hold the pilot's flight-plan type from the IFR clearance itself; restating it adds nothing they do not already have.

(6) ETA (estimated time of arrival) and name of the next reporting point.

(7) The name only, with no ETA, of the reporting point following the one named under (6).

(8) Remarks. When the pilot holds information relevant to ATC or to flight safety that is not captured by (1) through (7) (for example, ride quality, a deviation in progress, or an equipment problem), the pilot will include it here; otherwise, the pilot omits this item.

Example: Full Position Report (VFR, Flight-Plan Type Stated) Pilot: "Great Lakes Center, Cessna Three Four Bravo, Danby, three five, one one thousand, VFR, estimating Fenton at five two, Grail next, moderate chop last one zero miles." Required response: None. Center acknowledges only if a callback or clarification is needed.

Example: IFR Report Direct to Center (Flight-Plan Type Omitted Under d(5)) Pilot: "Great Lakes Center, Cessna Three Four Bravo, Danby, three five, one one thousand, estimating Fenton at five two, Grail next." Required response: None. Center acknowledges only if a callback or clarification is needed.

Call signs, facility names, fix names, and altitudes in the examples throughout this paragraph are generic placeholders for illustration only and are not asserted as real-world or network-published values.

5.17 Additional Reports

This paragraph establishes the reports a pilot gives to ATC or FSS without being asked, beyond the position reports established in paragraph 5.16, Position Reporting, and the initial-contact reports established in paragraph 5.15, ARTCC (Center) Communications. It applies to civil, military, formation, and airline traffic operating on an IFR flight plan, or on a clearance specifying VFR-on-top, alike; no category of traffic is exempt. It does not establish the PIREP (Pilot Weather Report) transmission format itself, established in the source AIM's Chapter 7, Pilot Weather Reports (PIREPs), which is not adapted into this contract; the procedure for a complete loss of two-way radio communication, established in the source AIM's Chapter 6, Two-Way Radio Communications Failure, which is not adapted into this contract; or any certificate-action, incident-investigation, or administrative-recordkeeping consequence of a missed report, all of which are outside the scope of this simulator's operational contract.

a. Controlled Terms. In the rules below, "Center" means the ARTCC sector working the aircraft. "Working facility" means whichever facility is currently in two-way radio contact with the pilot for the phase of flight in which the reportable event occurs: Departure, Approach, Center, Tower, or FSS.

b. Standard Reports. Whether or not the aircraft is in radar contact, the pilot should report each of (1) through (9) below to the working facility without being asked; absent one of these triggers, no report is due under this paragraph.

 (1) When vacating a previously assigned altitude or flight level for a newly assigned altitude or flight level, the pilot should report the vacating action to the working facility.

 (2) When operating on a clearance specifying VFR-on-top and making an altitude change, the pilot should report the change to the working facility.

Example: Altitude Change Report Pilot: "Denver Center, November One Two Three Alpha Bravo, leaving flight level three five zero for flight level three one zero." Required response: None. The working facility acknowledges receipt (for example, "roger," or a repeat of the call sign); no scripted read-back applies to this call.

 (3) When UNABLE to climb or descend at a rate of at least 500 feet per minute, the pilot should advise the working facility.

Example: Unable Required Rate Pilot: "Denver Center, Reach Three One, unable five hundred feet per minute, request lower." Required response: None. The working facility responds with revised instructions if the aircraft's climb or descent capability affects separation or a crossing restriction.

 (4) On executing a missed approach, the pilot should report the missed approach to the working facility and request further clearance (for example, to an alternate airport, or for another approach). Execution of the missed approach procedure itself is established in paragraph 5.29, Missed Approach.

Example: Missed Approach Report Pilot: "Springfield Tower, Trans Air Twelve, missed approach, request vectors for another ILS Runway Two Two." Required response: None. The working facility issues clearance for the action requested.

 (5) When the average true airspeed at cruising altitude varies from the value filed in the flight plan by 5 percent or 10 knots, whichever is greater, the pilot should report the revised true airspeed to the working facility. (See also paragraph 5.6.a, Flight Plan Revision.)

Example: True Airspeed Deviation Report Pilot: "Anchorage Center, Arctic One One, revised true airspeed, two four zero knots." Required response: None. The working facility may use the revised figure to update its own time estimate for the flight.

 (6) On reaching a holding fix or point to which cleared, the pilot should report the time and altitude or flight level to the working facility.

 (7) When leaving an assigned holding fix or point, the pilot should report the departure from the fix to the working facility.

Note: A pilot conducting instrument training at a military terminal facility, while that facility provides radar service, may omit the reports required by (6) and (7).

Example: Holding Fix Reports Pilot (reaching the fix): "Great Lakes Center, Trans Air Twelve, Danby, holding, zero three, one one thousand." Pilot (leaving the fix): "Great Lakes Center, Trans Air Twelve, leaving Danby." Required response: None.

 (8) On any loss, in controlled airspace, of VOR, TACAN (Tactical Air Navigation), ADF, or low-frequency navigation receiver capability; on any anomaly in an installed IFR-certified GPS (Global Positioning System) or GNSS (Global Navigation Satellite System) receiver; on complete or partial loss of ILS (Instrument Landing System) receiver capability; or on impairment of air-to-ground communications capability, the pilot should report the failure to the working facility, stating the aircraft's identification, the equipment affected, the degree to which the aircraft's ability to operate under IFR in the ATC system is impaired, and the nature and extent of the assistance desired.

Note: Equipment not listed in (8), for example airborne weather radar, that in the pilot's judgment affects safety of flight or IFR capability should be reported to the working facility using the same format as (8).

Note: A GPS anomaly report under (8) should include the anomaly's location and altitude, described specifically, and its duration if known at the time of the report.

Example: Navigation Equipment Failure Report Pilot: "Great Lakes Center, Cessna Three Four Bravo, VOR receiver failure, unable to comply with present routing, request radar vectors." Required response: None. The working facility responds with an alternate means of navigation or routing appropriate to the failure reported.

Example: GPS Anomaly Report Pilot: "Jacksonville Center, Reach Three One, GPS anomaly, lost primary navigation two zero miles north of Example VOR, flight level three three zero, duration approximately three minutes, now restored." Required response: None.

 (9) When, in the pilot's judgment, information relates to the safety of flight (discretion: no fixed list of qualifying events is published; the pilot determines what is relevant), the pilot should report the information to the working facility.

c. Nonradar Reports. When the aircraft is not in radar contact with the working facility, the pilot should report (1) and (2) below, in addition to the reports required by paragraph b; when the aircraft is in radar contact, no additional report is due under this paragraph.

 (1) On leaving the final approach fix inbound on a nonprecision approach, or the outer marker (OM) or the fix used in lieu of the outer marker inbound on a precision approach, the pilot should report to the working facility.

 (2) When a previously submitted time estimate proves in error by more than 2 minutes (3 minutes for a flight within the North Atlantic (NAT) organized track system), the pilot should provide a corrected estimate to the working facility.

Example: Nonradar Final-Segment Report Pilot: "Anchorage Radio, Arctic One One, over the outer marker, one one hundred, ILS Runway Two Five." Required response: None.

Example: Corrected Time Estimate Pilot: "Anchorage Radio, Arctic One One, revised estimate, Farewell, four one, one one thousand." Required response: None.

d. Weather Reports. On encountering weather that was not forecast, or hazardous weather conditions that were forecast, the pilot should report the conditions to the working facility; otherwise, no report is required under this paragraph. The PIREP content and transmission format are established in the source AIM's Chapter 7, Pilot Weather Reports (PIREPs), which is not adapted into this contract.

Call signs, facility names, fix names, altitudes, and frequencies in the examples throughout this paragraph are generic placeholders for illustration only and are not asserted as real-world or network-published values.

5.18 Airways and Route Systems

a. Purpose. This paragraph establishes the fixed route systems a pilot files and flies in the en route environment (the Federal airway system, the jet route system, and published RNAV routes), the altitude band, charting, and equipage tied to each, the rule for filing a route segment shared by multiple published routes, the conditions under which Center may vector an aircraft off an assigned route, and the airspace-classification differences a pilot must account for in Canadian-modeled airspace.

b. Scope. This paragraph governs route selection, filing, and equipage for the Federal airway system, the jet route system, and published and unpublished RNAV routes, together with the radio calls tied to a controller-initiated or pilot-requested radar vector off an assigned route. It applies to civil, military, formation, and airline traffic filing or flying these routes alike; no category of traffic uses a separate route structure. It does not establish the content or timing of a position report, established in paragraph 5.16, Position Reporting; the procedure for a mid-route course change, established in paragraph 5.19, Airway or Route Course Changes; the issuance of an IFR clearance itself, established in paragraph 4.29, Clearance; or lost-communications procedures, established in the source AIM's Chapter 6, Two-Way Radio Communications Failure, which is not adapted into this contract.

c. Controlled terms. "Victor airway" and "colored airway" both denote a segment of the Federal airway system predicated on a VOR or L/MF (Low/Medium Frequency) facility; they are distinguished only by identifier format, at paragraph e. "Jet route" denotes the separate high-altitude system at paragraph f, predicated on VOR or VORTAC (a combined VOR and TACAN facility) facilities. "RNAV route" denotes a Q-route, T-route, or Y-route at paragraph g, predicated on satellite or DME (Distance Measuring Equipment)/DME/IRU (Inertial Reference Unit) navigation rather than a ground-based facility. "Center" carries the meaning established in paragraph 5.15, ARTCC (Center) Communications. "Class B," in this paragraph's Canadian-airspace content at subparagraph j, denotes a Canadian controlled-airspace category distinct from, and not to be confused with, any Class B airspace defined elsewhere in this manual; the two share a name and nothing else.

d. Route System Overview

Three fixed route systems serve en route navigation: the Federal airway system (Victor airways and colored airways), the jet route system, and published RNAV routes. The systems overlap at shared fixes and altitude boundaries so that a flight can transition from one to another without a course discontinuity. Table 1 summarizes identification and charting; paragraphs e through g state the operating rules for each.

Note: The Alaska-specific navigation-aid substitutions noted under paragraphs e and g apply only where the network models Alaska en route airspace. Where it does not, those notes are inert.

Table 1. Route System Identification

Item	Route Type	Altitude Band	Chart Color	Identifier Format
1	Victor (VOR/L-MF) airway	1,200 ft AGL (or higher, as charted) up to but not including 18,000 ft MSL	Black (brown in Alaska)	V + number (e.g., V9)
2	Colored (L/MF) airway	Same as Item 1	Brown	Color name + number (e.g., Amber 1)
3	Jet route	18,000 ft MSL to FL (Flight Level) 450, inclusive	Black (brown in Alaska)	J + number (e.g., J50)
4	RNAV Q-route	18,000 ft MSL to FL 450, inclusive	Blue	Q + number (e.g., Q50)
5	RNAV T-route	1,200 ft AGL (or higher, as charted) up to but not including 18,000 ft MSL	Blue	T + number (e.g., T200)
6	RNAV Y-route	Oceanic and offshore airspace, including areas over southern Florida	Blue	Y + number (e.g., Y100)

Legend: AGL = above ground level; MSL = mean sea level; FL = Flight Level; VOR = VHF Omnidirectional Range; L/MF = Low/Medium Frequency; RNAV = Area Navigation.

e. Federal Airway System (Victor and Colored Airways)

(1) Victor airways, except in Alaska, are predicated solely on VOR or VORTAC navigation aids and are identified by "V" followed by the airway number (Table 1, Item 1).

Note: In Alaska, Victor airway segments are predicated on L/MF navigation aids instead of VOR and are charted in brown rather than black.

(2) The altitude limits at Table 1, Item 1 should not be exceeded except to transition within or between route structures.

(3) When two or more segments of a planned route share one airway number, the pilot files only that airway number for the portion of the route it covers, rather than listing each segment separately; otherwise, the pilot files each segment by its own identifier. Center and any handoff facility along the route will use the same airway number in clearances, readbacks, and route amendments.

EXAMPLE: IFR Clearance Readback Naming a Common Route Segment

CLEARANCE DELIVERY: "Cessna Three Four Bravo Charlie, cleared to Example Municipal Airport via Victor Nine, maintain eight thousand, expect further clearance one five past the hour, departure frequency one two one point niner, squawk four two one one."

PILOT: "Cleared to Example Municipal via Victor Nine, maintain eight thousand, expect further clearance one five past the hour, departure frequency one two one point niner, squawk four two one one, Three Four Bravo Charlie."

Required response: The pilot reads back the full clearance, including the route and altitude, before flight.

(4) Reporting points are designated along Victor airways for position reporting. The content and timing of a position report at one of these points is established in paragraph 5.16, Position Reporting; this paragraph governs only route selection and identification.

(5) Colored airways are predicated solely on L/MF navigation aids and are identified by a color name followed by the airway number (Table 1, Item 2; e.g., Amber 1). Green and Red colored airways run east-west; Amber and Blue colored airways run north-south.

(6) In Alaska, GPS/WAAS (Wide Area Augmentation System) equipment meeting TSO (Technical Standard Order)-C145 or TSO-C146 may serve as the sole means of navigation on a published ATS (Air Traffic Service) route at the lower MEA (Minimum En Route Altitude) published for GPS/WAAS use. Such an MEA is charted in blue and suffixed with the letter G.

f. Jet Route System

(1) Jet routes run from 18,000 ft MSL to FL 450 inclusive and are identified by "J" followed by the route number (Table 1, Item 3).

Note: In Alaska, jet route segments are predicated on L/MF navigation aids instead of VOR or VORTAC and are charted in brown.

(2) Except in Alaska, jet routes are predicated on VOR or VORTAC facilities. Reporting points are designated along jet routes for position reporting, established in paragraph 5.16, Position Reporting.

g. RNAV Routes

(1) Published RNAV routes (Q-routes, T-routes, and Y-routes) may be flight planned by an RNAV-capable aircraft and are RNAV 2 unless charted otherwise; an aircraft without RNAV capability may not file or fly them.

Note: RNAV 2 performance is currently met by GPS, GPS/WAAS, or DME/DME/IRU equipment.

(2) When filing or flying a Q-route, the pilot operates between 18,000 ft MSL and FL 450 inclusive (Table 1, Item 4).

Note: In Alaska, a GNSS Q-route requires either GPS meeting TSO-C129 or TSO-C196 with ATC radar surveillance, or GPS/WAAS without a radar-surveillance requirement.

(3) When filing or flying a T-route, the pilot operates from 1,200 ft AGL (or higher, as charted) up to but not including 18,000 ft MSL (Table 1, Item 5), using GPS or GPS/WAAS equipment.

Note: In Alaska, a GNSS T-route requires GPS/WAAS equipment meeting TSO-C145 or TSO-C146.

(4) When filing or flying a Y-route, the pilot must navigate using GPS. The pilot must also meet RNAV 2 performance for the entire flight on the Y-route. Y-routes lie in oceanic and offshore airspace, including areas over southern Florida (Table 1, Item 6).

(5) When flying an unpublished RNAV route (a direct route between waypoints defined by coordinates, degree-distance fixes, or offsets from an established route), Center will provide radar monitoring for the flight, except where the aircraft is GNSS-equipped and navigating via published waypoints, in which case no radar-monitoring requirement applies.

(6) A route's Magnetic Reference Bearing (MRB) is the published bearing between two waypoints on an RNAV, GPS, or GNSS route, computed by applying magnetic variation at the waypoint to the true course between the two waypoints.

Note: The MRB is a chart reference only. An aircraft's RNAV or GPS system navigates the route by true course or track, not by following the charted MRB directly.

h. Operations Above Flight Level 450

Above FL 450, an aircraft may operate point-to-point rather than on a charted route, using area navigation guidance from the facilities depicted on the applicable en route high-altitude chart.

i. Radar Vectors

(1) Within controlled airspace, Center may vector an aircraft off its filed route for separation, for noise abatement, when a vector offers an operational advantage to the pilot or to Center, or when the pilot requests it.

(2) Outside controlled airspace, Center will not vector an aircraft unless the pilot requests it.

(3) When Center initiates a vector that takes the aircraft off a previously assigned nonradar route, Center will state the purpose of the vector to the pilot.

EXAMPLE (illustrative phraseology): Controller-Initiated Vector Off a Nonradar Route

CENTER: "Speedbird Two Zero Two, fly heading two five zero, vectors for traffic, expect to rejoin Victor Nine in two zero miles."

PILOT: "Heading two five zero, Speedbird Two Zero Two."

Required response: The pilot reads back the assigned heading.

EXAMPLE (illustrative phraseology): Pilot-Requested Vector Outside Controlled Airspace

PILOT: "Center, Example One Two Three, request vectors to rejoin Jet Route Four, currently outside controlled airspace."

CENTER: "Example One Two Three, fly heading zero niner zero, vectors to rejoin Jet Route Four."

Required response: The pilot reads back the assigned heading.

(4) To the extent that traffic and workload permit, Center will allow an aircraft on an RNAV route to remain on its own navigation rather than vectoring it (discretion: no numeric or procedural threshold defines "to the extent possible"; the determination is Center's own, made against traffic and workload at the time).

j. Canadian-Modeled Airspace

(1) A pilot planning a flight through Canadian-modeled airspace should review the airspace-classification differences at (2) below before departure.

Note: Canadian controlled airspace does not follow the same class definitions a pilot may expect from U.S.-based charts and rules. A pilot who assumes otherwise risks operating under VMC in Canadian Class B airspace, at (2) below, without the clearance that (2) requires.

(2) Canadian Class B airspace is controlled airspace above 12,500 ft MSL, or above the MEA if the MEA is higher, in which only IFR and controlled VFR flights are permitted. Within Canadian Class B airspace, a pilot must not operate under VMC (Visual Meteorological Conditions) unless Center or the controlling facility has issued a VFR flight clearance, regardless of weather conditions or terrain height.

Note: Canadian Class B airspace, defined in (2) above, is not the same concept as Class B airspace elsewhere in this manual; the two categories share only a name (paragraph c).

Note: Canadian-published guidance also ties VFR entry into Canadian Class B airspace to a minimum pilot-certificate level and requires the pilot to maintain visual contact with the surface (ground or water) throughout the flight. Because the network does not verify a pilot's real-world certificate, the certificate-level condition is not independently enforceable here and is retained as background only; the VMC/clearance requirement at (2) above remains the operative rule.

(3) VOR airway and jet route segments in Canadian-modeled airspace are predicated on L/MF navigation aids and are charted in brown rather than blue or black.

Call signs, facility names, fix names, frequencies, and altitudes in the examples throughout this paragraph are generic placeholders for illustration only and are not asserted as real-world or network-published values.

5.19 Airway or Route Course Changes

This paragraph establishes each pilot's obligation to keep the aircraft's track within an airway's or route's lateral boundary through a course change, the discretion the pilot retains over turn technique, and the added lead-turn requirement above 290 knots true airspeed (TAS). It applies to civil, military, formation, and airline traffic on a filed route alike. It does not address minimum en route altitude, obstacle or terrain clearance, or separation from other traffic during a course change; those are governed elsewhere in this manual.

a. Track Adherence. While established on a published airway or route, each pilot MUST keep the aircraft's track within the published lateral boundary of that airway or route (consistent with Title 14, Code of Federal Regulations (14 CFR), Section 91.181).

(1) The turn technique used during a course change (turn radius, lead distance, and timing at the course-change fix) is at the pilot's discretion, based on wind direction and velocity, airspeed, the degree of course change required, and the navigation equipment on board. Each pilot MAY use available cockpit navigation equipment, such as distance-measuring equipment (DME), to lead the turn.

Note: A turn started at or after passing the course-change fix can carry the aircraft's track beyond the lateral boundary before the aircraft re-establishes on the new course; leading the turn reduces this risk.

Example: Standard Turn vs. Early (Lead) Turn (illustrative)

Standard turn: the aircraft begins the turn only after passing the course-change fix. For several seconds after the fix, its track lies outside the airway or route boundary before it regains course.
Early (lead) turn: the aircraft begins the turn before reaching the course-change fix. Its track stays inside the boundary throughout the course change.

b. High-Speed Course Changes. When operating at a TAS greater than 290 knots, each pilot MUST lead the turn at a course-change fix to remain within the published lateral boundary of the airway or route.

(1) At 290 knots TAS or below, the turn technique remains as described in paragraph a.(1).

Table 1. Worked Example: High-Speed Course Change Without a Lead Turn

Item	Parameter	Value
1	Altitude	17,000 ft MSL
2	True airspeed	400 kt TAS
3	Bank angle	25 degrees
4	Course change	greater than 40 degrees
5	Result without a lead turn	track exceeds the published boundary of 4 NM each side of centerline

Legend: MSL = mean sea level. TAS = true airspeed. NM = nautical mile.

Note: The values in Table 1 are the single worked example given in the source AIM for a high-speed course change. They show how altitude, TAS, bank angle, and course change interact and are not a formula for computing the required lead distance under other conditions.

c. ATC Coordination. A pilot who leads a turn under paragraph a.(1) or b., or whose track briefly exceeds the boundary before self-correcting during a course change, is not required to report the deviation to Center.

5.20 Holding

a. Purpose. This paragraph establishes when the controlling facility issues holding instructions, what a holding clearance contains, the maximum holding airspeed and leg timing a pilot flies while holding, the three standard holding-entry procedures, and the pilot reports and techniques required while holding at a fix.

b. Scope. This paragraph governs an aircraft holding at a fix under IFR, whether at a charted holding pattern or an uncharted fix, and whether the hold is assigned by Center or by Approach Control. It applies to civilian, military, formation, and airline traffic alike; no category of traffic is exempt. It does not govern the lost-communications procedure a pilot follows if no clearance can be obtained before or during a hold, governed by 14 CFR (Code of Federal Regulations) § 91.185; the procedure-turn or course-reversal timing of an instrument approach procedure that does not use a charted holding pattern in lieu of a procedure turn, established in paragraph 5.24, Instrument Approach Procedure (IAP) Charts; or the chart symbology a chart publisher uses to depict a holding pattern, established by the chart publisher and not restated here as a clause.

c. Controlled terms. In the rules below, "controlling facility" carries the meaning established in the Glossary, here narrowed to whichever of Center or Approach Control assigns the hold. "Clearance limit" means the fix, point, or location beyond which the aircraft is not cleared without further clearance; where a hold is assigned, the clearance limit and the holding fix are the same point unless the clearance states otherwise. "Holding fix" means the fix at which the holding pattern is flown. "EFC" means Expect Further Clearance, the time by which a pilot holding at a clearance limit can expect to receive clearance beyond it. "Standard holding pattern" means a holding pattern flown with right turns; "nonstandard holding pattern" means one flown with left turns.

d. Holding Instructions. When the controlling facility clears an aircraft to a clearance limit other than the destination airport and a delay is expected, the controlling facility WILL issue complete holding instructions, including an EFC time and, if known, the reason for and length of any additional delay expected en route or in the terminal area. When the assigned holding pattern is charted for the fix being used, the controlling facility MAY abbreviate the clearance under paragraph e; paragraph e governs what the controlling facility still includes in that case.

e. Charted Holding Patterns. When a holding pattern is charted at the assigned holding fix and the controlling facility issues no additional instructions, the pilot WILL hold as depicted on the chart. When the charted pattern lies on the procedure or route the aircraft is already flying, the controlling facility MAY abbreviate the clearance to the holding direction and the phrase AS PUBLISHED. When a pilot requests complete holding instructions despite a charted pattern being available, the controlling facility WILL issue them in full under paragraph g.

Note: Published holding patterns appear on U.S. government and FAA-approved commercial en route, area, Instrument Departure Procedure (DP), and Standard Terminal Arrival (STAR) charts. A nonstandard airspeed restriction for a charted pattern is shown inside the holding pattern symbol on the chart; paragraph i(2) governs how that charted value applies.

EXAMPLE: Charted Holding Clearance (Abbreviated) CENTER: "November Four Seven Golf, hold east of NELLY as published, expect further clearance one four five zero zulu." PILOT: "Hold east of NELLY as published, expect further clearance one four five zero zulu, November Four Seven Golf."

Note: The pilot's readback above is the required response. It confirms direction, fix, and EFC even though leg length, course, and turn direction are not restated, because those elements are already fixed by the chart.

f. Uncharted Holding Fix. When no holding pattern is charted at the fix and the controlling facility has not issued holding instructions, the pilot SHOULD request complete holding instructions from the controlling facility before reaching the fix. When the pilot cannot obtain holding instructions before reaching the fix because two-way communication cannot be established, the pilot MUST enter a standard holding pattern (paragraph c) on the inbound course on which the aircraft approached the fix, and MUST request further clearance as soon as communication is reestablished. In that case the controlling facility protects the airspace at the aircraft's last assigned altitude or flight level for separation.

g. Holding Clearance Elements. When the controlling facility issues a holding clearance for an uncharted fix, or for a charted fix under paragraph e where the pilot has requested full instructions, the controlling facility WILL include the following, in order:

(1) Direction of holding from the fix, using one of the eight cardinal or intercardinal points (N, NE, E, SE, S, SW, W, NW).

(2) The holding fix. The controlling facility MAY omit this if the fix was already stated earlier in the same transmission.

(3) Holding course: the radial, course, bearing, airway, or route the aircraft holds on.

(4) Leg length: stated in nautical miles (NM) if the aircraft holds by Distance Measuring Equipment (DME) or Area Navigation (RNAV), or in minutes if the pilot requests a time-based leg or the controlling facility determines a time-based leg is needed.

(5) Direction of turn, stated only if the turns are left turns, the pilot requests it, or the controlling facility determines it is needed. When turn direction is not stated, the pilot WILL fly a standard holding pattern (paragraph c).

(6) EFC time: the time the pilot can expect clearance beyond the holding fix, plus any expected-delay information available under paragraph d.

EXAMPLE: Full Holding Clearance (Uncharted Fix) CENTER: "November Four Seven Golf, hold west of NELLY on the zero niner zero radial, one zero mile legs, right turns, expect further clearance one four five zero zulu." PILOT: "Hold west of NELLY on the zero niner zero radial, one zero mile legs, right turns, expect further clearance one four five zero zulu, November Four Seven Golf."

Note: Full readback of all six elements is the required response. A partial readback does not confirm the clearance was correctly received.

h. Clearance-Limit Reports and Continuation.

(1) When no delay is expected at the clearance limit, the controlling facility SHOULD issue clearance beyond the fix as soon as possible and, in any case, at least 5 minutes before the aircraft is expected to reach the clearance limit. When a clearance beyond the fix is issued before the aircraft reaches the clearance limit, the pilot does not enter holding.

(2) When an aircraft reaches its clearance limit without having received clearance beyond it, the pilot MUST report the time and the altitude or flight level at which the aircraft reached the clearance limit. When the aircraft subsequently leaves the clearance limit, the pilot MUST report the time it does so.

Note: A pilot who cannot make either report in (2) above because two-way communication has failed follows the lost-communications procedure at 14 CFR § 91.185, not this paragraph.

EXAMPLE: Reaching and Leaving a Clearance Limit PILOT: "Center, November Four Seven Golf, NELLY, one five, one one thousand." (Later, on receiving clearance beyond the fix:) PILOT: "Center, November Four Seven Golf, leaving NELLY."

i. Maximum Holding Airspeed.

(1) When holding at an unpublished fix, or at a published fix where no other maximum is charted, the pilot MUST hold at or below the maximum indicated airspeed in Table 1 for the aircraft's holding altitude.

Table 1: Maximum Holding Airspeed by Altitude

#	Altitude (MSL)	Maximum Airspeed
1	At or below 6,000 ft	200 KIAS
2	6,001 ft to 14,000 ft	230 KIAS
3	Above 14,000 ft	265 KIAS

Legend: MSL = Mean Sea Level; KIAS = Knots Indicated Airspeed.

(2) When a charted holding pattern between 6,001 ft and 14,000 ft MSL displays a nonstandard-airspeed icon, the maximum holding airspeed for that pattern is 210 KIAS in place of Table 1. When a charted pattern instead displays a specific airspeed value inside the holding symbol, that charted value governs in place of Table 1.

(3) When holding at a U.S. Air Force (USAF) airfield with no other maximum charted, the maximum holding airspeed is 310 KIAS. When holding at a U.S. Navy airfield with no other maximum charted, the maximum holding airspeed is 230 KIAS.

EXAMPLE: Military Airfield Maximum Holding Airspeed CENTER: "Rebel One One, hold north of BRAVO as published, maximum airspeed three one zero knots, expect further clearance two zero one five zulu." PILOT: "Hold north of BRAVO as published, three one zero knots, expect further clearance two zero one five zulu, Rebel One One."

(4) When holding a helicopter or powered-lift aircraft on a COPTER procedure with no other minimum charted, the pilot maintains at least 90 KIAS to minimize wind drift, unless a different minimum is charted.

(5) When holding while climbing to the assigned holding altitude (climb-in-hold), the maximum holding airspeed is 310 KIAS unless a lower maximum is published for that hold.

Note: The USAF and Navy values in (3) above apply at those services' own airfields. Elsewhere, Table 1 and any charted restriction under (2) above control regardless of the aircraft's operator.

j. Speed Compliance at the Holding Fix.

(1) When an aircraft is 3 minutes or less from its clearance limit and has not received clearance beyond it, the pilot MUST begin reducing speed so as to cross the holding fix at or below the maximum holding airspeed established in paragraph i.

(2) When the pilot cannot comply with the maximum holding airspeed in paragraph i, the pilot MUST advise the controlling facility immediately and request an alternate clearance.

EXAMPLE: Unable to Comply with Maximum Holding Airspeed PILOT: "Center, November Four Seven Golf, unable two three zero knots for the hold, request higher block or vectors." CENTER: "November Four Seven Golf, roger, fly heading zero niner zero, vectors for spacing."

k. Holding Pattern Entry. When entering a holding pattern, the pilot WILL fly one of the following three procedures, selected by the aircraft's heading at the fix relative to the holding course (paragraph n(4) states the heading tolerance used to select among them):

(1) Parallel entry: parallel the outbound holding course on the nonholding side for 1 minute, turn through more than 180 degrees, and return to the fix or intercept the inbound course.

(2) Teardrop entry: proceed to the fix, then turn outbound to intercept a track making a 30-degree angle with the reciprocal of the inbound holding course, on the holding side, for 1 minute, then turn to intercept the inbound course.

(3) Direct entry: proceed to the fix and turn to follow the holding pattern.

When the assigned holding pattern is nonstandard under paragraph c, the pilot flies the fix-end and outbound-end turns as left turns and orients the entry procedures in (1) through (3) above to the nonholding side accordingly.

Note: The 1-minute entry timing in (1) and (2) above matches the standard inbound leg timing in paragraph l(1). Above 14,000 ft MSL, the pilot extends entry timing to 1.5 minutes, consistent with paragraph l(1).

l. Leg Timing and Distance.

(1) When holding on a time-based leg at or below 14,000 ft MSL, the pilot WILL fly a 1-minute inbound leg. When holding on a time-based leg above 14,000 ft MSL, the pilot WILL fly a 1.5-minute inbound leg. The pilot begins timing over or abeam the holding fix, whichever occurs later.

(2) When flying the first outbound leg of a time-based hold, the pilot WILL time it to match the inbound leg length in (1) above. On each subsequent circuit, the pilot WILL adjust the outbound leg timing so that the following inbound leg again matches the length required by (1) above.

(3) When holding on a DME- or RNAV-defined leg, the pilot WILL end the outbound leg at the DME or Along-Track Distance (ATD) reading the controlling facility or the procedure specifies, measured from the holding fix.

EXAMPLE: DME Leg Length Computation Holding fix at 10 NM DME, 5 NM legs specified, inbound course proceeding toward the NAVAID: the outbound leg ends at 15 NM DME. Holding fix at 28 NM DME, 8 NM legs specified, inbound course proceeding away from the NAVAID: the outbound leg ends at 20 NM DME.

m. RNAV Holding.

(1) When flying a published RNAV holding pattern and more than one hold is defined at the same fix, the pilot MUST confirm the pattern extracted from the aircraft's navigation database matches the assigned pattern's turn direction, leg length or timing, and maximum airspeed before entering it.

(2) When the controlling facility assigns a hold at a fix with no published RNAV holding pattern, the pilot WILL manually program the aircraft's RNAV system with the course, leg length, and turn direction from paragraph g.

Note: An RNAV system may fly the pattern by ground track rather than heading, producing an unexpected entry in a strong crosswind. It may fly a wider pattern than charted at a reduced bank angle, particularly at higher altitude, and may compute the turn from the outbound to the inbound leg farther from the fix than the charted turn point, particularly with a headwind. It cannot warn the pilot if the resulting pattern exceeds the fix's protected airspace, because that protected-airspace boundary is not in the aircraft's navigation database. The pilot remains responsible for staying within the protected airspace regardless of what the RNAV system displays.

n. Bank Angle, Wind Correction, and Entry Heading.

(1) When flying a non-RNAV holding pattern, the pilot SHOULD use whichever produces the smallest bank angle of the following three: 3 degrees per second, 30 degrees, or 25 degrees if using a flight director.

(2) When flying an RNAV holding pattern, the pilot allows the RNAV system to compute the turn. The pilot SHOULD NOT limit the bank angle below 25 degrees unless the aircraft's operating limitations, or the minimum maneuvering speed for the holding airspeed flown, require a lower angle.

(3) When correcting for wind drift while holding, the pilot SHOULD apply drift correction primarily on the inbound and outbound legs, using approximately three times the inbound heading correction on the outbound leg (for example, an 8-degree left correction inbound becomes a 24-degree right correction outbound).

(4) When determining entry sector under paragraph k, the pilot WILL use the aircraft's heading at the fix, within 5 degrees, to select the entry procedure; an RNAV system MAY compute the entry instead.

(5) When flying an RNAV direct entry and the turn from outbound to inbound has not begun within a reasonable distance of the charted leg length, the pilot SHOULD reduce speed, use the 25-degree bank angle in (2) above, and advise the controlling facility if the outbound leg is becoming excessive.

o. VOR Station Holding. When holding directly over a VOR station used as the holding fix, the pilot WILL begin the turn to the outbound leg when the TO/FROM indicator completes its first full reversal.

p. Airspace Protection and Radar Monitoring.

(1) When assigning a hold at an uncharted fix, the controlling facility WILL separate the aircraft from other traffic and from obstructions. The controlling facility WILL assign a holding altitude at or above the applicable Minimum Vectoring Altitude (MVA) or Minimum IFR Altitude, whichever applies.

(2) The controlling facility WILL monitor holding pattern airspace on radar where able. When radar shows an aircraft outside the protected airspace, the controlling facility WILL attempt to assist it back into the pattern. When workload, traffic volume, precipitation, ground clutter, or radar coverage prevents this monitoring, the pilot's responsibility to remain within the protected airspace under paragraphs k and l is unaffected.

(3) When an aircraft is established in a published holding pattern at an assigned altitude above the published minimum holding altitude, and the controlling facility issues an approach clearance, the pilot MAY descend to the published minimum holding altitude.

Note: A holding pattern is a segment of an instrument approach procedure only where the approach chart publishes it in lieu of a procedure turn.

q. Minimum Holding Altitude (Unpublished Pattern). When holding at a fix with no published minimum holding altitude, the pilot WILL maintain the last assigned altitude until leaving the holding pattern and established on the inbound course. The pilot then WILL comply with the published minimum altitude for the route segment being flown. The controlling facility WILL assign a holding altitude that allows a normal descent on the inbound course once clearance beyond the fix is received.

r. Timed Approach Clearance from Holding. When the controlling facility assigns a specific time to depart the holding fix, the pilot WILL adjust the flight path within the holding pattern to leave the fix at that time. After departing the fix, the pilot WILL resume normal speed under any applicable terminal-area speed restriction or controlling-facility request. When timed approaches are in progress at the destination, the pilot MUST NOT execute a procedure turn after leaving the holding pattern unless the pilot first advises the controlling facility.

Note: An aircraft holding at the final approach fix during timed approaches proceeds inbound to the final approach directly from the hold once cleared for the approach; an unadvised procedure turn in that situation could conflict with the timed sequence.

EXAMPLE: Timed Departure from Holding CENTER: "November Four Seven Golf, depart NELLY at one five five two zulu." PILOT: "Depart NELLY at one five five two zulu, November Four Seven Golf."

Call signs, fix names, radials, and times in the examples throughout this paragraph are generic placeholders for illustration only and are not asserted as real-world or network-published values.

Arrival

This part establishes arrival, approach, and landing procedures: Standard Terminal Arrival routes, Approach Control's role, advance approach information, how to read and comply with an instrument approach chart, approach-clearance routing and phraseology, aircraft approach categories, radar approaches, landing minimums, the missed approach, and the visual, contact, and overhead-maneuver alternatives to a standard instrument approach.

Note: Paragraphs in this part repeatedly need a term for "whichever facility is currently providing air traffic control service to the aircraft for the arrival action in question." This chapter uses controlling facility for that concept throughout this part, defined fully in the Glossary. Two source paragraphs (now 5.24 and 5.26) originally used "ATC" for the identical referent; both have been converted to "the controlling facility" here so the term is not read as a second, different concept.

5.21 Standard Terminal Arrival (STAR) Procedures

a. Purpose. This paragraph establishes what a Standard Terminal Arrival (STAR) is, when a controlling facility may include one in an aircraft's clearance, the pilot's chart, database, and speed and altitude compliance obligations while flying one, the phraseology and mechanics of a DESCEND VIA clearance, the pilot report required after receiving one, and the navigation-equipage requirement for a STAR built on Performance-Based Navigation (PBN).

b. Scope. This paragraph governs Standard Terminal Arrival routes flown under IFR by any aircraft, civil, military, formation, or airline, inbound to an airport served by one; no category of traffic is exempt. It does not establish the general airspace speed limits of 14 CFR (Code of Federal Regulations) § 91.117, or the RESUME NORMAL SPEED, RESUME PUBLISHED SPEED, COMPLY WITH SPEED RESTRICTIONS, or DELETE SPEED RESTRICTIONS phraseology, all established in paragraph 4.39, Speed Adjustments; the content or timing of a position report, established in paragraph 5.16, Position Reporting; the lost-communications procedure a pilot follows after a complete loss of two-way radio communication, governed by 14 CFR § 91.185; where STAR charts are published or distributed, an administrative matter with no radio-communication or in-flight-procedure relevance; or the technical certification criteria for a PBN-capable navigation system, a maintenance and certification matter with no operational relevance to phraseology or procedure.

c. Controlled terms. "STAR" means Standard Terminal Arrival, an ATC-coded arrival route linking the en route structure to an airport's instrument approach procedures (paragraph d). "Controlling facility" carries the meaning established in the Glossary. "DESCEND VIA" denotes the clearance form at paragraph k; it is a controlled phrase and is always set in full capitals where it appears. "PBN" means Performance-Based Navigation.

d. STAR Definition and Assignment. A STAR is a preplanned lateral path, often carrying published altitude and speed restrictions, that a controlling facility uses in place of individually clearing an aircraft fix by fix from the en route structure to the terminal area. When an aircraft's IFR flight is destined to an airport served by a published STAR, the controlling facility may include the STAR in the aircraft's clearance.

Note: Which specific facility (Clearance Delivery, Center, or Approach) issues the STAR clearance for a given flight is briefed every mission; no standing assignment holds across every field and network.

e. Chart and Navigation Database Requirements. Before accepting a STAR clearance, the pilot must have access to at least the current chart for that procedure. When the STAR is an RNAV (Area Navigation) STAR, the procedure must be retrievable by name from the aircraft's navigation database, and the retrieved procedure must conform to the charted one.

f. Declining a STAR. The pilot may decline a STAR. When declining one filed in advance, the pilot will state NO STAR in the remarks section of the flight plan. When declining one issued after the flight plan is filed, or when no flight plan was filed, the pilot will advise the controlling facility verbally.

EXAMPLE: Declining a STAR PILOT: "Center, Reach Three One, request no STAR, vectors to final." CENTER: "Reach Three One, roger, expect vectors."

Required response: the controlling facility assigns a clearance that does not include the STAR.

g. Altitude Compliance. When a pilot has been cleared onto a STAR without a DESCEND VIA instruction, the pilot must maintain the last assigned altitude until the controlling facility issues further clearance authorizing descent to comply with a published or assigned altitude restriction.

Note: An MEA (Minimum En Route Altitude) published on a STAR segment is not itself an altitude restriction; the pilot must remain at or above the applicable MEA absent an instruction from the controlling facility authorizing descent below it.

h. Speed Restriction Compliance. Where a STAR publishes a speed restriction at a waypoint, the pilot will cross that waypoint at the published speed, and must not exceed it beyond the waypoint, unless the controlling facility authorizes a different speed or a published chart note states otherwise.

Note: An altitude or speed printed on a STAR with an "expect" label is planning information only. It is not a clearance and does not bind the pilot unless the controlling facility assigns it verbally or in a subsequent clearance.

(1) Where a STAR chart note specifies a transition from a Mach number to an indicated airspeed (IAS), the pilot will maintain the charted cruise Mach number until reaching the published transition speed, stated in knots, then continue the descent at that IAS until the next published speed restriction, or until the general airspace speed limits established in paragraph 4.39, Speed Adjustments, require a change.

i. STAR Cancellation and Rejoin. When the controlling facility vectors the pilot off a STAR's charted lateral path, or otherwise issues an instruction that deviates from it, the pilot will consider the STAR, and any of its published altitude or speed restrictions, canceled. The controlling facility will assign an altitude to maintain and, if needed, a speed to maintain.

When the controlling facility intends to return the pilot to the STAR, the controlling facility will state the fix or leg where the pilot can expect to rejoin it. The pilot should be prepared to resume compliance with the published restrictions from that point, using the COMPLY WITH SPEED RESTRICTIONS phraseology established in paragraph 4.39, Speed Adjustments.

j. STAR Clearance Forms. A STAR clearance takes one of the forms in Table 1.

Table 1. STAR Clearance Forms

#	Form	What It Authorizes
1	Lateral routing only	The charted lateral path; no descent; published speed restrictions apply.
2	Lateral routing with an assigned altitude	The charted lateral path and published speed restrictions; the pilot levels at the stated altitude pending further clearance.
3	DESCEND VIA	The charted lateral path, and descent at the pilot's discretion to meet each published altitude and speed restriction (paragraph k).
4	DESCEND VIA with an amended restriction	As Item 3, except the controlling facility's stated restriction replaces the charted value at the named fix.
5	Direct-to-waypoint intercept, then DESCEND VIA	Descent, at the pilot's discretion, from the previously assigned altitude to the altitude charted at the named waypoint, then Item 3 for the remainder of the procedure.

Note: Callsigns, waypoint names, and procedure names in the examples below are drawn from the source AIM's own illustrative examples; they are not asserted as currently charted, real-world procedures.

EXAMPLE 1: Lateral Routing Only CENTER: "Jetstream Four Seven, cleared Tyler One arrival." PILOT: "Cleared Tyler One arrival, Jetstream Four Seven."

EXAMPLE 2: Lateral Routing With an Assigned Altitude CENTER: "Jetstream Four Seven, cleared Tyler One arrival, descend and maintain flight level two four zero." PILOT: "Cleared Tyler One arrival, descend and maintain flight level two four zero, Jetstream Four Seven."

Note: The controlling facility may instead state "descend at pilot's discretion, maintain flight level two four zero" in place of "descend and maintain," authorizing the pilot to choose the timing and rate of the descent to the stated altitude.

EXAMPLE 3: Descend Via APPROACH: "Gulfstream Two Three Papa Echo, descend via the Eagul Five arrival." PILOT: "Descend via the Eagul Five arrival, Gulfstream Two Three Papa Echo."

EXAMPLE 4: Descend Via With an Amended Restriction APPROACH: "Gulfstream Two Three Papa Echo, descend via the Eagul Five arrival, except cross Vnnom at or above one two thousand." PILOT: "Descend via the Eagul Five arrival, except cross Vnnom at or above one two thousand, Gulfstream Two Three Papa Echo."

EXAMPLE 5: Direct-to-Waypoint Intercept, Then Descend Via CENTER: "Gulfstream Two Three Papa Echo, proceed direct Denis, cross Denis at or above flight level two zero zero, then descend via the Mmell One arrival." PILOT: "Direct Denis, cross Denis at or above flight level two zero zero, then descend via the Mmell One arrival, Gulfstream Two Three Papa Echo."

Required response for each example above: the pilot reads back the clearance as issued.

k. Descend Via Mechanics. When cleared DESCEND VIA a STAR, the pilot may descend at the pilot's discretion to meet each published altitude restriction while navigating the STAR's charted lateral path. Once established on the depicted arrival, the pilot must meet every published or assigned altitude and speed restriction on it.

(1) When cleared direct to a waypoint on the STAR that carries a published altitude, in conjunction with a DESCEND VIA clearance, the pilot may descend from the previously assigned altitude, at the pilot's discretion, to the altitude charted at that waypoint (Table 1, Item 5).

(2) Compliance with a DESCEND VIA clearance does not relieve the pilot of speed-restriction compliance under paragraph h. Independent of a DESCEND VIA clearance, the pilot will adjust speed far enough in advance of each waypoint to cross it at the published speed, and will maintain that speed until the next published restriction requires a change or until the general airspace speed limits established in paragraph 4.39, Speed Adjustments, apply.

(3) When issuing a DESCEND VIA clearance, the controlling facility must ensure obstacle clearance for the aircraft along the cleared path.

(4) When no altitude is depicted at a waypoint or fix on the STAR for an aircraft routed directly to it, the controlling facility will assign an altitude to maintain.

l. Descend Via Pilot Report. On initial contact with a new controlling facility after being cleared DESCEND VIA a STAR, the pilot will report the elements in Table 2.

Table 2. Descend Via Report Elements

#	Element	Condition
1	Altitude leaving	Always
2	DESCENDING VIA (procedure name)	Always
3	Assigned runway transition, or landing direction	Only if one was assigned
4	Any assigned restriction not published on the chart	Only if one applies

EXAMPLE: Descend Via Report, Runway Transition Assigned PILOT: "Approach, Delta One Twenty One, leaving flight level one niner zero, descending via the Eagul Five arrival, runway two-six transition."

EXAMPLE: Descend Via Report, Landing Direction Assigned PILOT: "Approach, JetBlue Six Zero Two, leaving flight level two one zero, descending via the Ivane Two arrival, landing south."

Required response: the controlling facility acknowledges the report, or issues a correction if it conflicts with the aircraft's current clearance; no other specific reply content is prescribed.

m. Performance-Based Navigation (PBN) STARs. Where a STAR is designated for PBN, the pilot's aircraft and navigation database must support the navigation specification charted in the procedure's PBN notes box, normally RNAV 1, RNP (Required Navigation Performance) 1, or A-RNP (Advanced RNP). When the aircraft or database cannot meet the charted specification, the pilot must decline the STAR under paragraph f and request an alternate clearance.

Note: RNAV 1 and RNP 1 require the aircraft's navigation system to remain within 1 NM (nautical mile) of the charted path for at least 95 percent of the time flown on the procedure. An A-RNP procedure charts its own minimum accuracy value in the PBN notes box in place of this figure.

Note: An "expect" altitude or routing on a STAR (paragraph h, Note) may become operationally significant if the pilot loses two-way radio communication; that scenario is governed by 14 CFR § 91.185, not restated here.

Callsigns, procedure names, waypoint names, altitudes, and frequencies in the examples above are illustrative; where drawn from the source AIM's own example phraseology, they illustrate the phraseology form only and are not asserted as currently charted, real-world procedures.

5.22 Approach Control

a. Purpose. This paragraph establishes the approach control facility's role in receiving and sequencing arriving instrument traffic released from Center, the two release methods used to hand an aircraft to approach control, the vectoring and approach-clearance procedure to the final approach course, the reduced-precision handling used when Center itself provides approach control service at certain airports, and when radar service to an arrival terminates.

b. Scope. This paragraph governs communications and procedure between Approach (or Center, where Center itself provides approach control service under paragraph i) and an aircraft under IFR receiving vectors, radar-approach service, or a clearance to an instrument approach. It applies to civil, military, formation, and airline traffic alike; no category of traffic is exempt. It does not establish the procedure or minima for any individual instrument approach type (ILS, RNAV, VOR, PAR, ASR, or other), established in paragraph 5.24, Instrument Approach Procedure (IAP) Charts, and paragraph 5.28, Approach and Landing Minimums; the missed approach procedure itself, established in paragraph 5.29, Missed Approach; or the clearance and pattern procedure for a visual approach, established in paragraph 5.30, Visual Approach.

c. Controlled terms. "Approach" means the approach control facility serving the arrival airport, or, where an ARTCC sector itself performs this service under paragraph i, that Center sector acting in the approach-control role. "Center" carries the meaning established in paragraph 5.15, ARTCC (Center) Communications, and denotes the en route ARTCC sector working the aircraft before release to Approach. "Final approach course" means the extended course specified for the instrument approach procedure (IAP) the aircraft is flying. "Final approach fix (FAF)" means the fix on that IAP beyond which the final approach segment begins.

d. Facility Role and Handoff from Center

(1) Within its area of responsibility, Approach WILL control arriving aircraft operating on an instrument flight plan, primarily through direct two-way communication between Approach and the pilot. A single Approach facility MAY serve more than one airport.

(2) Before an aircraft reaches the destination airport's radio facility, Center WILL instruct the pilot to contact Approach on a specified frequency.

EXAMPLE: Handoff from Center to Approach CENTER: "Speedbird Four Niner Two, contact Example Approach one two five point three five." PILOT: "One two five point three five, Speedbird Four Niner Two."

e. Radar Service to the Final Approach Course

(1) Where radar is approved for approach control service, Approach WILL use it both for a radar approach (Airport Surveillance Radar (ASR) or Precision Approach Radar (PAR)) and to provide vectors toward the final approach course of a published nonradar instrument approach procedure (IAP) predicated on a navigational aid (NAVAID) such as an Instrument Landing System (ILS), VHF Omnidirectional Range (VOR), Non-Directional Beacon (NDB), or Tactical Air Navigation (TACAN) facility, or toward the traffic pattern for a visual approach.

(2) When releasing an arriving aircraft to Approach, the releasing facility WILL do one of the following:

 (a) clear the aircraft to the outer fix most appropriate to the filed route, with vertical separation from other traffic, and include holding instructions if a hold is required; or

 (b) where a radar handoff to Approach is used (between Center and Approach, or between two Approach facilities), clear the aircraft to the airport or to a fix positioned so that the handoff completes before the aircraft reaches it; under this method, the releasing facility MAY hand off successive arriving aircraft to Approach using radar separation instead of the vertical separation used under (a) above.

f. Vectors to the Final Approach Course

(1) When vectoring an aircraft toward the final approach course (for example, an ILS, RNAV, GLS (GBAS Landing System), VOR, or ADF (Automatic Direction Finder) course), Approach WILL issue the radar vectors and altitude or flight-level assignments needed for spacing and separation; the specific vectors and altitudes assigned are at Approach's discretion, based on traffic (no fixed value is specified in this paragraph). While being vectored, the pilot MUST NOT deviate from a heading Approach has assigned.

(2) When a vector will carry the aircraft across the final approach course for spacing or another reason, Approach WILL inform the pilot before doing so. When course crossing appears imminent and Approach has not given that advisory, the pilot SHOULD query Approach.

EXAMPLE: Vector Across the Final Approach Course APPROACH: "Example Three Four Bravo, expect vectors across the final approach course for spacing, fly heading zero niner zero." PILOT: "Heading zero niner zero, Example Three Four Bravo."

EXAMPLE: Pilot Query on an Unadvised Course Crossing PILOT: "Example Approach, Example Three Four Bravo, confirm we're being vectored across the final approach course." APPROACH: "Example Three Four Bravo, affirmative, fly heading two seven zero, expect to rejoin final in about two miles."

g. Approach Clearance

(1) Absent an approach clearance, the pilot MUST NOT turn inbound on the final approach course.

(2) When vectoring an aircraft to intercept the final approach course, Approach WILL issue the approach clearance together with the final vector for interception; that vector WILL be one that allows the pilot to establish the aircraft on the final approach course before reaching the FAF.

EXAMPLE: Approach Clearance with the Final Vector APPROACH: "Example Three Four Bravo, three miles from FENIX, turn left heading one eight zero, maintain two thousand until established, cleared ILS Runway Two Two approach." PILOT: "Left heading one eight zero, two thousand until established, cleared ILS Runway Two Two approach, Example Three Four Bravo."

(3) When an aircraft is already inbound on the final approach course, Approach WILL issue the approach clearance before the aircraft reaches the FAF. Once established inbound on the final approach course, Approach WILL maintain radar separation from the aircraft. The pilot WILL fly the approach using the approach aid designated in the clearance (for example, ILS, RNAV, GLS, VOR, or radio beacons) as the primary means of navigation.

(4) Once established on the final approach course under (2) or (3) above, the pilot MUST NOT deviate from it unless Approach issues a clearance to do so.

EXAMPLE: Established Inbound, Approach Clearance Issued Before the FAF APPROACH: "Example Three Four Bravo, four miles from the final approach fix, cleared RNAV Runway One Seven approach." PILOT: "Cleared RNAV Runway One Seven approach, Example Three Four Bravo."

h. Approach Completion

After passing the FAF on final approach, the pilot WILL continue inbound on the final approach course and either complete the approach or execute the published missed approach procedure for the airport (paragraph 5.29, Missed Approach).

i. Center-Provided Approach Control

(1) At an airport where the serving ARTCC is approved to provide approach control service directly, that Center sector WILL perform the functions in paragraphs d through h, acting in the approach-control role defined at paragraph c.

Note: An ARTCC's radar does not offer the same precision as the ASR or PAR used by an Approach facility or a tower, and its update rate is slower. For this reason, Center-provided approach control depends more on the pilot's own confirmation of course alignment than terminal radar typically does.

(2) When Center-provided approach control requests it, the pilot WILL report reaching the final approach course, using the call below.

EXAMPLE: Report Established on Final Approach Course (Center-Provided Approach Control) CENTER: "Example Three Four Bravo, report established on the final approach course." PILOT: "Example Three Four Bravo, established."

j. Termination of Radar Service

When the aircraft completes the landing, or Approach instructs the pilot to change to the applicable advisory frequency (typically the Common Traffic Advisory Frequency (CTAF)) at an uncontrolled airport, whichever occurs first, radar service terminates automatically. This applies whether the aircraft was vectored to the final approach course under paragraphs e through g or navigated to it on its own equipment along a published route.

EXAMPLE: Radar Service Termination, Uncontrolled Airport APPROACH: "Example Three Four Bravo, radar service terminated, change to advisory frequency approved, report cancellation this frequency or on the ground with Example Radio." PILOT: "Change to advisory approved, Example Three Four Bravo, good day."

Call signs, facility names, fix names, and frequencies in the examples throughout this paragraph are generic placeholders for illustration only and are not asserted as any real facility's published values.

5.23 Advance Instrument Approach Information

This paragraph establishes when Approach advises a pilot of the type of instrument approach to expect before arrival, what that advisory means and does not mean, and the pilot reporting and advisory-frequency broadcast procedures used when the arrival airport has automated weather but no control tower or FSS in operation.

Note: "Controlling facility" carries the meaning established in the Glossary. Paragraph a. is Approach-specific, because it applies only where an approach control facility is in operation; paragraphs b. through d. use "controlling facility" because either Approach or Center may be working the aircraft at that point.

a. Expected Approach Advisory. At an airport served by Approach where two or more Instrument Approach Procedures (IAPs) are published, Approach will advise the pilot, before arrival, of the type of approach to expect or that the pilot may instead be vectored for a visual approach. Approach will issue this information by radio, by Automatic Terminal Information Service (ATIS) broadcast, or by both. When the reported visibility is 3 statute miles (SM) or better and the ceiling is at or above the highest initial approach altitude published for any low-altitude IAP at the airport, Approach does not issue this advisory.

Note: The ceiling reference above is the highest initial approach altitude among the airport's own published low-altitude IAPs. It is not a fixed value; it varies by airport and by which procedures are published there.

Example: Expected Approach Advisory

Approach: "Cessna Three Alpha Bravo, expect the ILS Runway Two Seven approach."

Note: No read-back is required. The approach type, runway, and callsign above are illustrative; Approach substitutes whatever type and runway actually apply.

b. Deviation from the Advised Approach. When the pilot becomes unable to fly the approach Approach has advised, or prefers a different published approach, the pilot must advise the controlling facility immediately. Otherwise, no notification is required and the pilot flies the approach as advised.

Note: The advisory in a. is a planning aid, not an ATC clearance or commitment, and is subject to change. Fluctuating weather, shifting wind, or a blocked runway are conditions that may change it after it is issued.

Example: Unable the Advised Approach

Pilot: "Approach, Cessna Three Alpha Bravo is unable the ILS Runway Two Seven, request the RNAV Runway Zero Niner."

Approach: "Cessna Three Alpha Bravo, roger, expect the RNAV Runway Zero Niner, fly heading one eight zero, vectors for the approach."

Note: The controlling facility's response above is illustrative. Exact phrasing, and whether an amended clearance or vectors are issued, is at the controller's discretion.

c. Weather Acknowledgment at Uncontrolled Airports. When flying an IFR arrival to an airport with no control tower that has Automated Surface Observing System / Automated Weather Observing System (ASOS/AWOS) broadcast capability, the pilot should monitor the ASOS/AWOS frequency to obtain the airport's current weather. On receiving the broadcast weather, the pilot must advise the controlling facility that the weather has been received and state intentions. When the pilot cannot receive the broadcast weather, the controlling facility will issue the last long-line disseminated weather instead.

Note: Where the airport's ASOS/AWOS has no human-observer backup, the system is normally set to broadcast weather updates every 1 minute.

Note: The controlling facility treats long-line disseminated automated weather as trend and planning information only. Determining whether weather and visibility are adequate for the approach and landing is the pilot's (or aircraft operator's) responsibility, not the controlling facility's.

Example: Weather Received at an Uncontrolled Field

Center: "November Four Five Six Charlie Delta, cleared direct SPRINGFIELD, RNAV Runway One Eight approach, Springfield has no tower, monitor ASOS one one eight point three two five and advise when weather is received."

Pilot: "Four Five Six Charlie Delta has the Springfield weather, will execute the RNAV Runway One Eight approach."

d. Advisory-Frequency Broadcasts on Approach. When the controlling facility transmits CHANGE TO ADVISORY FREQUENCY APPROVED to a pilot flying an IFR approach to an airport with no tower or FSS in operation, the pilot should broadcast, on the appropriate advisory frequency (UNICOM or other, as published), the pilot's intentions, including the type of approach being flown and the aircraft's position. When over the final approach fix (FAF) inbound on a nonprecision approach, or over the outer marker (OM) or the fix used in lieu of the outer marker inbound on a precision approach, the pilot should make an additional position broadcast on the advisory frequency. After switching to the advisory frequency, the pilot should continue monitoring it for position reports from other aircraft.

Example: Change to Advisory Frequency and Position Broadcasts

Controlling facility: "November Four Five Six Charlie Delta, change to advisory frequency approved."

Pilot (advisory frequency): "Springfield traffic, November Four Five Six Charlie Delta, seven-mile final, RNAV Runway One Eight approach, Springfield."

Pilot (crossing the FAF, advisory frequency): "Springfield traffic, November Four Five Six Charlie Delta, final approach fix inbound, RNAV Runway One Eight approach, Springfield."

Note: CHANGE TO ADVISORY FREQUENCY APPROVED is the fixed ATC phraseology that authorizes the pilot to leave the controlling facility's frequency for the advisory frequency. The pilot's own broadcasts on that frequency are not scripted and vary with the airport, procedure, and traffic in the pattern.

Note: Callsigns, fix names, airport names, approach types, headings, and frequencies in the examples throughout this paragraph are generic placeholders for illustration only and are not asserted as real-world or network-published values.

This paragraph does not establish the wording or issuance of an approach clearance itself (paragraph 5.25, Approach Clearance), ATC separation standards, or the lost-communications procedure a pilot follows if two-way communication fails before or during arrival (a topic of the source AIM's Chapter 6, Two-Way Radio Communications Failure, not adapted into this contract).

5.24 Instrument Approach Procedure (IAP) Charts

a. Purpose. This paragraph establishes how a pilot reads and complies with a published Instrument Approach Procedure (IAP) chart: the procedure types a chart may depict, how a chart identifies the navigation equipment a procedure requires, the altitude and obstacle-clearance conventions a chart uses, the Terminal Arrival Area (TAA) a pilot flies to enter an RNAV approach without vectors, and the additional minima lines, symbology, and notes an RNAV (GPS) chart carries.

b. Scope. This paragraph governs civilian, military, formation, and airline traffic alike; no category of traffic is exempt. It applies to any IAP charted for use in the simulated environment, whether flown under civil ("FAA") or military charting. It does not govern the phraseology or timing of an approach clearance itself, established in paragraph 5.25, Approach Clearance; it does not govern the lost-communications procedure a pilot follows after a two-way radio failure, governed by 14 CFR § 91.185; and it does not restate aircraft approach-category speed breakpoints (Category A/B/C/D/E), which are defined in the Pilot/Controller Glossary and are not repeated here. This paragraph does not address real-world procedure certification, flight-inspection, or enforcement action against a chart or its use; those are outside the simulated environment.

c. Controlled Terms. In the rules below, "TERPS" means the United States Standard for Terminal Instrument Procedures, the joint civil-military criteria set used to design every IAP. "Controlling facility" carries the meaning established in the Glossary: whichever facility (Approach Control, Center, or Tower) is currently working the aircraft. "GPS" means Global Positioning System; "WAAS" means Wide Area Augmentation System, a satellite-based augmentation to GPS; "DME" means Distance Measuring Equipment. A Precision Approach (PA) provides course and glidepath guidance meeting ICAO (International Civil Aviation Organization) Annex 10 precision standards (for example, ILS (Instrument Landing System), PAR (Precision Approach Radar)). An Approach with Vertical Guidance (APV) provides course and glidepath guidance not required to meet PA standards (for example, LPV, LNAV/VNAV, or Baro-VNAV (Barometric Vertical Navigation), an RNAV function that computes vertical guidance from the aircraft's own barometric altimeter). A Nonprecision Approach (NPA) provides course guidance only, with no glidepath (for example, VOR, NDB, or LNAV (Lateral Navigation)); a published Vertical Descent Angle (VDA) on an NPA is an advisory descent aid and does not make the approach an APV. "VNAV" means Vertical Navigation. "IAF" means Initial Approach Fix; "IF" means Intermediate Fix. "HILPT" means Hold-in-Lieu-of-Procedure-Turn, a holding pattern flown at a fix in place of a course-reversal procedure turn. "NoPT" means a route or sector labeled to show that no course reversal is authorized on that transition. "MSA" means Minimum Safe Altitude; "MVA" means Minimum Vectoring Altitude. "TAA" means Terminal Arrival Area. "ROC" means Required Obstacle Clearance, the vertical buffer TERPS design adds above the controlling obstacle when computing a minimum altitude. "DA" (Decision Altitude) is the Mean Sea Level (MSL) altitude, on a PA or APV procedure, at which the pilot must decide to land or execute the missed approach if the required landing environment is not in sight; "MDA" (Minimum Descent Altitude) is the MSL altitude, on an NPA or a circling procedure, below which the pilot may not descend without the required landing environment in sight.

d. Procedure Design and Charting Authority. Every IAP is designed to TERPS criteria and is prescribed and published by the appropriate civil or military authority for the airport, facility, terrain, obstacles, and noise environment it serves. A civil procedure is charted "FAA"; a military procedure is charted with the owning service's designator (for example, USAF, USN, USA). When flying any IAP charted for the simulated environment, the pilot WILL fly the altitudes, courses, and limitations the procedure specifies, or accept radar vectors and altitude assignments from the controlling facility (Approach Control, Center where Center provides approach control service, or Tower) in place of the charted transition; either method assures obstacle and terrain clearance to the runway.

Note: A civil pilot flying a military IAP is bound by that airport's own instrument procedures and minimums while operating there. Some networks and missions treat certain military fields as requiring prior coordination before an arrival is worked; where the network briefs such a requirement, it is a network/mission convention and not restated here as a clause.

e. Procedure Title and Required Navigation Equipment.

(1) When reading a straight-in IAP title, the pilot WILL identify the required navigation system from the system name paired with the runway number (for example, "VOR RWY 13"). When reading a circling-only IAP title, the pilot WILL identify it from the system name paired with a letter in place of a runway number (for example, "VOR A").

(2) When two navigation systems in a title are separated by a slash, both are required (for example, "VOR/DME RWY 31"). When two systems are separated by "or," either alone is sufficient (for example, "VOR or GPS RWY 15").

(3) When a procedure requires equipment beyond the primary system named in the title, for a segment outside the final approach course (including the missed approach), the chart's pilot-briefing (notes) box states the added requirement (for example, "DME REQUIRED," "RADAR REQUIRED," "ADF REQUIRED"). When equipment is required for procedure entry from the en route structure, the same requirement is instead noted in the plan view.

(4) Before accepting or requesting a given IAP, the pilot WILL confirm the aircraft carries and can use every navigation system the chart requires for the entire procedure, including the missed approach.

(5) When more than one approach of the same type serves the same runway, each is distinguished by a letter suffix assigned from the end of the alphabet backward (for example, "ILS Z RWY 28," then "ILS Y RWY 28"), or, for multiple ILS procedures to the same runway, by Category (CAT I/II/III) designation where no other multiple exists.

Note: A chart may additionally carry a separate Performance-Based Navigation (PBN) box (navigation specification, required sensors, and minimum RNP (Required Navigation Performance) value) alongside or in place of a conventional equipment-requirements box. Where both appear, the PBN box is read first; every item inside either box is a requirement, not an option.

f. Altimeter Setting Source. Unless the chart states otherwise, approach minima are computed against the local airport's own altimeter setting. When the procedure authorizes or requires a different or additional altimeter source, the chart states the source and the minima adjustment that applies when that source, rather than the local one, is used (for example, an added increment to each MDA). When the required altimeter setting cannot be obtained, the pilot MUST NOT fly to that procedure's charted minima.

Note: A Baro-VNAV system uses only the local altimeter setting. Where no local setting is available but a WAAS-equipped aircraft carries an alternate authorized source, Baro-VNAV is not authorized, but the WAAS receiver may still fly the LNAV/VNAV line of minima using satellite-based vertical guidance instead.

g. Charted Altitude Conventions.

(1) A charted altitude is one of four kinds, distinguished by how the value is marked on the chart:

Table 1: Charted Altitude Types

#	Marking	Type	Compliance
1	Underscored value	Minimum altitude	Maintain at or above the depicted value.
2	Overscored value	Maximum altitude	Maintain at or below the depicted value.
3	Both underscored and overscored	Mandatory altitude	Maintain the exact depicted value.
4	Neither mark	Recommended altitude	Descent-planning guidance only; not a restriction.

Legend: Underscore/overscore refer to a line printed below/above the altitude value on the chart.

(2) When ATC assigns an altitude that matches a charted value under Table 1, the pilot WILL comply with that value as a mandatory altitude regardless of the marking originally printed on the chart.

(3) When intercepting an ILS glidepath, the pilot SHOULD intercept it at the published glide-slope intercept altitude (marked by the "lightning bolt" symbol), which also marks the start of the final approach segment; obstacle clearance from that altitude down to the lowest published DA is assured only from that point of interception onward. When a pilot chooses to track the glidepath before reaching the published intercept altitude, the pilot remains responsible for complying with every charted stepdown-fix altitude on the segment being flown, exactly as if not yet on the glidepath.

(4) When conducting a simultaneous parallel (independent or dependent) approach, the pilot descends on the glidepath or glidepath-equivalent guidance from the altitude at which the approach clearance is issued; a chart-published Attention All Users Page (AAUP), where one exists for that approach, states whether descending on the glidepath alone satisfies the procedure's crossing restrictions. Where no AAUP addresses this, the pilot SHOULD independently monitor the descent outside the final approach fix to confirm compliance with published crossing restrictions.

(5) When a stepdown-fix altitude restriction is published inside the final approach segment of a nonprecision straight-in or circling line of minima (for example, annotated "LOC only" or "LNAV only"), the pilot flying that line of minima MUST comply with it. A pilot flying a PA or APV line of minima to a DA is not bound by a stepdown-fix restriction published inside the final approach segment. A stepdown restriction published outside the final approach segment (initial or intermediate) binds every pilot regardless of the line of minima flown.

Note: A PA or APV pilot is excused from the final-approach-segment stepdown restriction because that pilot's obstacle clearance instead follows the vertical guidance flown to the DA, not the stepdown fix.

h. Minimum Safe Altitude (MSA). An MSA is published on the IAP chart's plan view for emergency use only; it is not assessed for navigation-signal coverage and does not by itself authorize a descent. When operating within the plan view's charted MSA sector, an MSA provides 1,000 ft (feet) of obstacle clearance above the highest obstacle in that sector. MSA sectors are centered on the facility the procedure is predicated on (or the Airport Reference Point (ARP) where no such facility exists, or the RNAV waypoint for an RNAV procedure) and normally extend to a 25 NM (Nautical Mile) radius, expandable to 30 NM where needed to cover the airport's landing surfaces. Where obstacles require it, up to four sectors may be published, each with its own minimum altitude; otherwise a single sector covers the full radius.

i. Terminal Arrival Area (TAA).

(1) Design. The TAA provides a charted transition from the en route structure to an RNAV IAP with minimal controller interface. It is built on the "Basic T" design: two base-leg IAFs positioned on either side of a dual-purpose IF/IAF, from which the intermediate segment runs to the Final Approach Fix (FAF) and then to the Missed Approach Point (MAP). A HILPT anchors at the IF/IAF for course alignment or descent where needed.

(2) Boundaries and Sectors. The TAA divides into three areas at the IF/IAF: straight-in, left-base, and right-base. Lateral boundaries are magnetic courses TO the IF/IAF; the straight-in area may further subdivide by arc-defined stepdown sections, and each base area may subdivide by arcs based on distance from its own IAF.

(3) Entry and Course Reversal.

(a) When a sector or transition is labeled "NoPT," the pilot MUST NOT fly a HILPT course reversal on that transition. When a sector is not labeled "NoPT," the pilot WILL fly the HILPT course reversal under 14 CFR § 91.175, unless the controlling facility clears the aircraft straight-in under (b) below.

(b) When the aircraft's course to the IF/IAF lies within a "NoPT"-labeled straight-in sector and the intercept angle is 90 degrees or less, or when the controlling facility vectors the aircraft to the IF/IAF and issues a straight-in approach clearance, the pilot proceeds direct to the IF/IAF and flies the approach straight-in, without a HILPT course reversal. In every other case where the transition is not labeled "NoPT," the pilot flies the HILPT course reversal.

(c) When the controlling facility clears the aircraft direct to a left-base or right-base IAF, the controlling facility WILL NOT assign an intercept angle to that IAF exceeding 90 degrees.

(d) When the controlling facility clears an aircraft for the approach without specifying an IAF (for example, "cleared RNAV Runway 34 approach" with no fix named), the pilot proceeds direct to the IAF or IF/IAF associated with the entry sector the aircraft is in and completes a HILPT course reversal if that sector is not labeled "NoPT."

Note: A pilot approaching exactly on a sector boundary bearing follows the "NoPT" routing for that boundary unless the controlling facility instructs otherwise.

(4) Altitude Compliance. A TAA altitude replaces the MSA for that area and, unlike the MSA, is operationally usable: it provides at least 1,000 ft of obstacle clearance (more where mountainous-area criteria apply). To determine which TAA area applies, the pilot computes the magnetic bearing FROM the aircraft TO the IF/IAF and compares it to the published sector boundary bearings; bearing to a base-area IAF is not used for this determination. When cleared direct to an IAF or the IF/IAF without also receiving an approach clearance, the pilot MUST NOT descend to a lower TAA altitude on that basis alone; the pilot requests a lower altitude from the controlling facility if one is desired. Once cleared for the approach, the pilot MAY descend to the minimum altitude charted for the TAA sector currently occupied, planning the descent to allow a normal rate of descent from the IF/IAF to the FAF.

Note: A pilot experiencing two-way radio communications failure while within a TAA maintains the highest altitude required under 14 CFR § 91.185(c)(2) until reaching the appropriate IAF, notwithstanding a lower TAA altitude that would otherwise apply.

[VERIFY: the specific altitude/distance breakpoints used to illustrate base-area descent (for example, "6,000 ft until within 17 NM of the IAF, then descend; 2,000 ft once within 22 NM of the IF/IAF") are figure-specific values from one charted example in the source, not a universal numeric standard. Every TAA publishes its own altitudes and distances, and the pilot flies the values charted for that specific procedure, not a fixed figure.]

EXAMPLE: RNAV Approach Clearance with TAA Entry APPROACH: "Cessna Three Four Bravo, cross WEXOR at or above four thousand, cleared RNAV Runway Two Six approach." PILOT: "Cross WEXOR at or above four thousand, cleared RNAV Runway Two Six approach, Cessna Three Four Bravo."

Note: Fix name, altitude, and runway in the example above are generic placeholders for illustration; they are not asserted as a real or network-published procedure. The pilot in the example determines from the aircraft's bearing to WEXOR (the IF/IAF in this illustration) which TAA sector it is in, and whether a NoPT transition or a HILPT course reversal applies, per (3) above.

(5) Non-Standard TAA Shapes. When the standard "T" design would conflict with terrain or ATC requirements at a given airport, the TAA MAY publish with one or both base areas reduced or eliminated (for example, resembling a "Y," an inverted "L," or an "I"). In every case, the boundaries and "NoPT" labeling charted for that specific TAA govern; the pilot does not assume a standard three-area shape where the chart depicts otherwise.

j. Minimum Vectoring Altitude (MVA). An MVA is established for radar-vectoring use and is not charted on the IAP itself. When vectoring an aircraft, Approach Control or Center WILL NOT assign an altitude below the MVA applicable to the sector the aircraft occupies. Each MVA sector is bounded at least 3 NM from the obstruction that determines it (an isolated prominent obstruction MAY instead be enclosed in its own buffer area, at least 3 NM from the obstruction, to avoid raising the MVA over a larger surrounding sector).

(1) An MVA provides 1,000 ft of clearance above the highest obstacle in a nonmountainous sector, 2,000 ft above the highest obstacle in a designated mountainous sector, and, in every sector, at least 300 ft above the floor of controlled airspace. Where ATC surveillance capability supports it in a designated mountainous sector, 1,000 ft of clearance MAY be authorized in place of 2,000 ft.

(2) An MVA MAY be lower than the nonradar Minimum En Route Altitude (MEA), Minimum Obstruction Clearance Altitude (MOCA), or other charted minimum altitude for the same location.

Note: This is not a charting discrepancy. An MVA sector's shape and obstacle survey differ from those used to compute the MEA or MOCA for the same location, so the two values are not directly comparable.

(3) When an MVA or Minimum IFR Altitude (MIA) applicable to an aircraft's position is lower than the TAA minimum altitude for the segment the aircraft would otherwise fly, the controlling facility WILL either maintain the aircraft at the assigned altitude until it is established on a published route segment or the IAP, or climb it to the TAA altitude, before the TAA minimum applies.

k. Circling Minima. A charted circling line of minima MAY be lower than the LNAV/VNAV line for the same procedure but MUST NOT be lower than the LNAV straight-in line for that procedure. When circling, the pilot flying to the published circling MDA does so at the authorized aircraft approach category speed for that MDA; approach-category speed breakpoints are defined in the Pilot/Controller Glossary and are not restated here.

EXAMPLE: Circling Approach Clearance APPROACH: "November Two One Charlie, five miles from the airport, cleared VOR Runway Zero Four approach, circle to land Runway Two Two." PILOT: "Cleared VOR Runway Zero Four approach, circle to land Runway Two Two, November Two One Charlie."

l. Reduced-Visibility (RVR 1800) Landing Minima. When a runway does not carry touchdown zone and centerline lighting, the standard visibility minimum for its ILS is Runway Visual Range (RVR) 2400. When the chart instead publishes an RVR 1800 minimum for that runway (marked on the minima line and explained in a chart note), that lower visibility is authorized only when the pilot flies to DA using an operating flight director, an operating autopilot with an approved approach coupler, or a Head-Up Display (HUD).

Note: A single pilot flying an RVR 1800 approach to a runway without touchdown zone and centerline lighting SHOULD NOT rely on a flight director alone, without an autopilot, to meet the workload demand of that approach.

m. Obstacle-Clearance Basis for Published Minima. An NPA MDA is computed by adding 250 ft of ROC (rounded up to the next 20-ft increment, or more where design factors require) above the controlling obstacle for the LNAV line; a circling MDA is computed by adding 300 ft of ROC above the controlling obstacle within the circling evaluation area. A circling MDA MAY be lower than an LNAV/VNAV DA for the same procedure, or a circling MDA and an LNAV MDA MAY coincide.

Note: Neither outcome is a charting error. The LNAV, LNAV/VNAV, and circling lines may each rest on a different controlling obstacle, so their relative order from one procedure to the next is not fixed.

n. Visual Descent Point (VDP). A VDP, marked with a "(V)" symbol and identified by DME or RNAV along-track distance to the MAP, is the point on a nonprecision straight-in final approach course from which a stabilized visual descent from MDA to the runway may begin. Before reaching the charted VDP, the pilot SHOULD NOT descend below the MDA. Where an obstacle penetrates the visual segment between the MDA and the runway, where the procedure provides no distance-measuring capability, or where design otherwise prevents identifying one, the chart WILL NOT publish a VDP for that procedure; the pilot flying such a procedure treats it as though no VDP exists and remains especially attentive between MDA and the MAP under paragraph o below.

o. Visual-Segment Obstacles and Night Operations. TERPS design evaluates the visual segment (the segment beyond the MDA/DA toward the runway) for obstacles on every IAP, but that evaluation does not create an obstacle-free guarantee below the MDA/DA. Below the MDA or DA, and through the landing maneuver, the pilot MUST visually acquire and avoid obstacles in the visual segment; no clearance is assured by the chart or the procedure in that segment.

(1) When an unlighted obstacle penetrates the visual segment, the chart WILL carry a note prohibiting night use of the affected procedure (a note to the effect of "Procedure NA (Not Authorized) at Night").

(2) When a Visual Glideslope Indicator (VGSI) is installed and approved to restore night use in place of obstruction lighting, the chart WILL instead carry a note authorizing night straight-in use conditioned on an operating VGSI and on the pilot remaining at or above the VGSI glidepath to the threshold.

p. Charted Obstacles. The highest obstacle (man-made structure, terrain, or vegetation) in the plan view is charted to the nearest foot MSL; additional obstacles MAY be charted in the plan view or airport sketch as space allows. When an obstacle's elevation has not been field-verified, the chart marks it with a "±" symbol following the elevation.

q. Vertical Descent Angle (VDA) and Threshold Crossing Height (TCH). On a nonprecision procedure other than one flown to circling-only minimums, one with no FAF, or one already flown to vertically guided minima, the chart WILL publish a VDA and a corresponding TCH in the profile view, computed from the FAF or last stepdown fix. A VDA is advisory: it aids a stabilized, constant-rate descent but does not itself guarantee obstacle clearance in the visual segment below the MDA.

(1) When an obstacle penetration below the MDA would otherwise force the pilot to deviate from the published VDA between the MDA and the runway, the chart WILL replace the VDA/TCH with a note to the effect of "Visual Segment - Obstacles" in place of a numeric angle; the pilot flying such a procedure plans the descent from MDA expecting to maneuver around a charted obstacle rather than following a straight descent path.

(2) Where no PA or APV procedure exists to the same runway, the published VDA equals or exceeds the angle of any VGSI installed on that runway, where design criteria allow; a chart note identifies any case where the VGSI angle does not match the VDA.

(3) TCH is typically 30 to 50 ft above the runway threshold, absent a chart note stating a different value for a larger aircraft type using that IAP.

(4) On a procedure restricted to circling-only minimums because the straight-in descent gradient would exceed the design maximum, a published VDA does not imply that a straight-ahead landing is recommended or possible; the pilot flying that procedure selects the circling maneuver appropriate to the aircraft's performance, independent of the VDA.

r. Published Visual Flight Path ("Fly Visual to Airport"). When an IAP charts a dashed-arrow segment in the plan and profile views labeled "Fly Visual to Airport" or "Fly Visual," the pilot flies that segment by reference to any advisory guidance the chart provides, by pilotage, or by both, maintaining flight visibility not less than the visibility required for that IAP and remaining clear of clouds while proceeding visually to the airport. The altitude flown on that segment is at the pilot's discretion (discretion: no standard altitude applies; a recommended altitude MAY be charted for planning only); the pilot remains responsible for visually acquiring and avoiding obstacles on that segment.

Note: A missed approach initiated below the MDA/DA, or after continuing beyond the MAP, is not assured obstacle clearance by the charted missed approach procedure; the pilot flying a "Fly Visual to Airport" segment SHOULD brief a climb-out option, based on aircraft performance and known terrain, before initiating the approach.

EXAMPLE: Fly Visual to Airport Clearance APPROACH: "Lifeguard Four One, airport in sight, fly visual to airport, contact Tower one one eight point three." PILOT: "Fly visual to airport, contact Tower one one eight point three, Lifeguard Four One."

s. RNAV (GPS) Minima Lines and Required Avionics. An RNAV (GPS) chart MAY publish up to five lines of minima on a single procedure, distinguished by the guidance and avionics each requires:

Table 2: RNAV (GPS) Minima Lines

#	Line	Vertical Guidance	Minimum Type	Representative Required Avionics
1	GLS	Precision (ground-based)	DA	GBAS (Ground-Based Augmentation System) receiver; published on a separate GLS-titled chart.
2	LPV	APV (satellite-based, angular)	DA	WAAS receiver approved for LPV.
3	LNAV/VNAV	APV (satellite- or barometric-based)	DA	WAAS receiver, or approach-approved Baro-VNAV system.
4	LP	Lateral only (angular, no glidepath)	MDA	WAAS receiver approved for LP; published only where terrain or obstacles preclude an LPV or LNAV/VNAV line.
5	LNAV	Lateral only	MDA	GPS or WAAS receiver approved for approach operations.

Legend: GLS = GBAS Landing System; LPV = Localizer Performance with Vertical Guidance; LNAV = Lateral Navigation; VNAV = Vertical Navigation; LP = Localizer Performance; MDA = Minimum Descent Altitude; DA = Decision Altitude; WAAS = Wide Area Augmentation System; Baro-VNAV = Barometric Vertical Navigation.

(1) Before flying to a given minima line, the pilot WILL confirm the aircraft's installed and approved avionics support that line, per the aircraft's flight manual or supplemental flight manual statement. An aircraft's approval for LPV does not by itself imply approval for LP. A GPS-only (non-WAAS) receiver MUST NOT be flown to a WAAS-dependent line (GLS, LPV, LNAV/VNAV, or LP).

(2) When a procedure's minima depend on RNP and the note "DME/DME RNP-0.3 NA" is published, an aircraft relying on DME/DME updating for RNP-0.3 is not authorized that line. When the note instead names specific required DME facilities for DME/DME RNP-0.3, the pilot flying with DME/DME updating WILL ensure the aircraft receives signal from those named facilities to fly that line. Absent either note, DME/DME updating for RNP-0.3 is not otherwise restricted under this paragraph. The pilot MUST NOT use VOR/DME updating for RNAV approach navigation.

(3) On a procedure that also publishes an ILS or LOC line alongside RNAV (GPS) minima, GPS-based guidance may be inhibited on some receiver installations whenever any ILS frequency is tuned. On such an installation, the pilot WILL wait until established on the intermediate segment, before the FAF, to tune the ILS frequency. The pilot MUST retune away from the ILS frequency before flying an RNAV-based missed approach.

Note: Two temperature-related notes may appear in the procedure's notes box independent of the minima lines above: a Baro-VNAV temperature-range limitation on some PBN charts, and a Cold Temperature Airport (CTA) limitation, marked with a snowflake icon and a minimum temperature, requiring an altimetry correction below that temperature; the correction procedure itself is established in the source AIM's Chapter 7, Cold Temperature Barometric Altimeter Errors, Setting Procedures and Cold Temperature Airports, which is not adapted into this contract, and is not restated here.

t. RNAV Chart Symbology and Waypoint Sequencing.

(1) When flying an RNAV or GPS IAP, the pilot flies it from the procedure retrieved by name from the aircraft's navigation database, not from manually entered waypoints, and the navigation system sequences each database waypoint as either fly-by (turning in advance of the fix) or fly-over (flying over the fix before turning). When the navigation system does not itself distinguish fly-by from fly-over sequencing, the pilot manually leads the turn or overflies the fix, as charted, to match the intended track.

(2) When flying a WAAS-capable receiver with channel-number selection, the pilot MAY select the procedure's five-digit WAAS Channel Number directly, cross-checking the four-character Approach ID displayed against the chart's pilot briefing to confirm the correct final approach segment is loaded, in place of menu-based procedure selection.

(3) When a "negative W" WAAS vertical guidance outage symbol is charted on an RNAV (GPS) approach, LNAV/VNAV or LPV vertical service at that location is subject to unscheduled outage with no NOTAM (Notice to Air Missions) or ATC advisory issued for it. When planning that IAP as a destination or alternate procedure, the pilot plans using the LNAV or circling line of minima. When the avionics indicate LNAV/VNAV or LPV service is available at the time of the approach, the pilot MAY fly to that displayed service level, reverting to the LNAV or circling line if service is lost during the approach.

u. Practice Instrument Approaches at Military/DoD Facilities. When conducting a practice VFR approach using a DoD (Department of Defense) IAP, the civil pilot MUST first obtain approval from the controlling facility for that field.

Note: Landing at, or requesting services from, a military or other Prior Permission Required (PPR) field beyond a practice approach is a network- or mission-specific coordination matter and is not restated here as a clause; where the network or mission briefs a PPR or coordination requirement for a given field, that briefing governs.

Fix names, callsigns, altitudes, and frequencies in the examples throughout this paragraph are generic placeholders for illustration only and are not asserted as real-world or network-published values.

5.25 Approach Clearance

a. Purpose. This paragraph establishes the routing a pilot follows once cleared for an instrument approach; the controlling facility's obligations when routing an aircraft direct to a fix or naming an approach with an inoperative component; what an approach clearance that does not name a specific procedure authorizes; the requirement to fly a procedure in its entirety; how a STAR connects to an approach in the aircraft's own RNAV system; the altitude, heading, and course-reversal rules that apply when radar vectors or a direct clearance are combined with an approach clearance; the constraints on RNAV RF-leg routing; and the phraseology used to cancel an approach clearance.

b. Scope. This paragraph governs the routing, phraseology, and pilot compliance obligations tied to an approach clearance issued by Approach or Center to an aircraft on an IFR flight plan. It applies to civil, military, formation, and airline traffic alike; no category of traffic is exempt. It does not establish how an IAP chart depicts altitudes, minima, or course-reversal symbology, established in paragraph 5.24, Instrument Approach Procedure (IAP) Charts; the general vectoring, handoff, and radar-service role of Approach Control, established in paragraph 5.22, Approach Control; STAR altitude and speed compliance mechanics, established in paragraph 5.21, Standard Terminal Arrival (STAR) Procedures; or the elements of a holding clearance or an EFC (Expect Further Clearance) time generally, established in paragraph 5.20, Holding, except as paragraph k(8) below applies arrival holding to an approach. It does not govern the missed approach procedure flown after passing the missed approach point, established in paragraph 5.29, Missed Approach; the clearance and pattern procedure for a visual or contact approach, established in paragraph 5.30, Visual Approach, and paragraph 5.31, Contact Approach; or the lost-communications procedure a pilot follows after a complete loss of two-way radio communication, governed by 14 CFR § 91.185.

c. Controlled terms. "Controlling facility" carries the meaning established in the Glossary. "IAF" (Initial Approach Fix) and "IF" (Intermediate Fix) carry the meanings established in paragraph 5.24, Instrument Approach Procedure (IAP) Charts, as do "NoPT" (a route or sector labeled to show no course reversal is authorized) and "HILPT" (Hold-in-Lieu-of-Procedure-Turn). "FAF" (Final Approach Fix) carries the meaning established in paragraph 5.22, Approach Control. "STAR" carries the meaning established in paragraph 5.21, Standard Terminal Arrival (STAR) Procedures. "Holding fix" carries the meaning established in paragraph 5.20, Holding. "Feeder route" means a published off-airway route connecting the en route structure to an IAF. "Procedure turn (PT)" means a charted maneuver that reverses an aircraft's inbound track onto the final approach course. "Course reversal" means a PT or a HILPT, whichever is charted at the fix in question; where a rule below applies to "the course reversal," it applies equally to whichever of the two is charted. "RF leg" (Radius-to-Fix leg) means a constant-radius circular path around a defined turn center, charted on some RNAV procedures, beginning and ending at fixes.

d. Feeder Routes as Part of the Approach Clearance. When the controlling facility has cleared an aircraft to a holding fix and then issues an approach clearance, that approach clearance does not by itself authorize new routing; the pilot WILL proceed via the last assigned route, and any published feeder route from that route to the IAF, to begin the approach. A published feeder route connecting the en route structure to the IAF is part of the approach clearance itself.

e. Feeder Route or IAF Already on the Route Flown. When a published feeder route to the IAF begins at a fix on the aircraft's current route before the assigned holding fix, and the controlling facility issues an approach clearance, the pilot WILL begin the approach via that feeder route rather than continuing to the holding fix and returning. When the IAF itself lies on the aircraft's current route to the holding fix, the pilot WILL begin the approach at the IAF on that same basis.

f. Direct Routing to the IAF. When the controlling facility intends to route an aircraft directly to the IAF instead of via the holding fix or a published feeder route, the controlling facility WILL state that intent using phraseology that includes the word DIRECT. When a pilot is uncertain whether a clearance authorizes direct routing to the IAF, the pilot SHOULD query the controlling facility before proceeding.

EXAMPLE: Direct Routing to the Initial Approach Fix CENTER: "Cactus Eight One Two, proceed direct HUXLY, cleared RNAV Runway One Niner approach." PILOT: "Direct HUXLY, cleared RNAV Runway One Niner approach, Cactus Eight One Two."

g. Approach Naming with an Inoperative Component. A published instrument approach procedure keeps its charted name even when one of its guidance components (for example, the glideslope of an ILS) becomes inoperative or unreliable. When issuing an approach clearance for a procedure with an inoperative or unreliable component, the controlling facility MUST advise the pilot of that component, except where the procedure's own title already reflects the reduced guidance available (for example, a chart titled to cover both ILS and LOC (localizer-only) minimums on one procedure needs no separate advisory when only the localizer is usable).

EXAMPLE: Approach Clearance with an Inoperative Component Advisory APPROACH: "Learjet Two Six Hotel, glideslope unreliable, cleared ILS Runway One Four approach." PILOT: "Glideslope unreliable, cleared ILS Runway One Four approach, Learjet Two Six Hotel."

h. Approach Clearance Without a Named Procedure. When the controlling facility issues an approach clearance without naming a specific procedure (cleared approach), the pilot MAY execute any instrument approach procedure published for that airport. This clearance MAY be issued with routing to or over an IAF or a feeder fix. This clearance does not authorize a contact approach or a visual approach.

EXAMPLE: Unspecified Approach Clearance APPROACH: "Skywest Four Four, five miles from KRAFT, cleared approach." PILOT: "Cleared approach, Skywest Four Four."

Note: In the example above, the pilot selects any authorized instrument approach procedure published for the airport; the clearance does not by itself indicate which one, and it does not authorize a contact approach or a visual approach.

i. Executing the Entire Procedure. When cleared for an instrument approach, the pilot MUST fly the entire published procedure, beginning at the IAF or an associated feeder fix as depicted on the IAP chart. This requirement ends only when the controlling facility issues a new or revised ATC clearance, or the pilot cancels the IFR flight plan.

j. STAR-to-Approach Continuity. When a STAR terminates at a fix that is also charted as the IAF or IF of an instrument approach, and the STAR's published instructions indicate that an approach can be expected from that fix, the pilot MUST load the approach in the aircraft's RNAV system beginning at that IAF or IF, so that the STAR and the approach are joined as one continuous route. The controlling facility WILL clear the aircraft for the approach by naming that IAF or IF together with the approach clearance.

Note: When loading an approach under this paragraph, the pilot SHOULD NOT select a vectors-to-final or vectors-only option in the RNAV system; doing so can prevent the system from sequencing the IAF or IF and increases pilot workload during the transition.

EXAMPLE: STAR Terminating at a Shared IAF CENTER: "Jetlink Seven Seven, cross CACTU at one one thousand, cleared RNAV Runway Two Four approach." PILOT: "Cross CACTU at one one thousand, cleared RNAV Runway Two Four approach, Jetlink Seven Seven."

Note: CACTU above is a generic placeholder for a fix that serves as both a STAR's last waypoint and an approach's IAF; it is not asserted as a real charted fix. The source AIM illustrates this same connection using the fix RDFSH transitioning into the ILS RWY 27 approach at Houston Intercontinental (KIAH); a pilot's own navigation database, not this document, shows which fixes serve this dual role at a given airport.

[VERIFY: the RDFSH/KIAH/ILS RWY 27 identification above was reconstructed from a single research pass and was not cross-checked against a current chart; confirm before treating it as authoritative.]

k. Radar Vectors and Direct Clearances Combined with an Approach Clearance. Paragraphs (1) through (8) below apply whenever the controlling facility combines a radar vector or a direct-to clearance with an approach clearance.

(1) Altitude. When the aircraft has not yet reached a published segment of the procedure, the pilot WILL maintain the last assigned altitude until established on a segment with a lower charted altitude. When the aircraft is already established on a published route or segment of the procedure, the pilot MAY descend to the minimum altitude published for that segment.

(2) Heading. While being vectored under this paragraph, the pilot WILL continue on the assigned heading until intercepting the next published ground track that applies to the approach.

(3) Reaching the Final Approach Fix via Published Segments. Once the aircraft reaches the FAF having flown the published segments leading to it, the pilot MAY continue the approach to landing.

(4) Required Course Reversal. When cleared to an IAF or IF that carries a charted course reversal, and the controlling facility has not cleared the aircraft straight-in, the pilot MUST fly the charted course reversal before continuing the approach.

(5) No Procedure Turn (NoPT) Routes. When cleared to an IAF or IF via a route or transition labeled NoPT, or when the procedure publishes no course reversal at that fix, the pilot WILL continue the approach on the published track without flying a course reversal.

(6) RNAV Direct-to-IAF/IF and Direct-to-Intermediate-Segment Clearances. When the controlling facility clears an RNAV-equipped aircraft direct to an IAF or IF, the controlling facility WILL NOT assign an intercept angle to that fix greater than 90 degrees. When the controlling facility instead clears the aircraft direct to a fix between the IF and the FAF, the controlling facility WILL NOT assign an intercept angle to that fix greater than 30 degrees. The controlling facility WILL assign an altitude for the direct routing that provides obstacle clearance and allows a normal descent to the FAF.

When the controlling facility clears an aircraft direct to an IAF or IF that carries a charted course reversal, and does not want the course reversal flown, the controlling facility MUST issue a straight-in approach clearance rather than relying on (4) above.

When providing this direct routing, the controlling facility WILL radar monitor the aircraft to the IF and WILL advise the pilot, at least 5 NM (nautical miles) before the IF, that direct routing to the IF should be expected.

Note: The requirement that the controlling facility state whether a clearance is straight-in relates to 14 CFR § 91.175(i); this paragraph does not restate that regulation's descent-below-DA/MDA (Decision Altitude/Minimum Descent Altitude) criteria.

EXAMPLE: RNAV Direct-To with Straight-In Clearance APPROACH: "Viper One One, proceed direct WABIT, cleared straight-in RNAV Runway Zero Six approach." PILOT: "Direct WABIT, cleared straight-in RNAV Runway Zero Six approach, Viper One One."

(7) Direct Clearance to a Final Approach Fix That Is Also Charted as an IAF. When the controlling facility clears an RNAV-equipped aircraft direct to a FAF that is also charted as an IAF, the pilot MUST fly the charted course reversal; the controlling facility WILL NOT issue a straight-in clearance for this routing. To fly the approach straight-in instead, the pilot MAY request vectors to intercept outside the FAF, or fly a published NoPT route to the same fix.

[VERIFY: whether a separate allowance exists for a direct-to-FAF clearance specifically on a visual approach procedure; this was not confirmed against the source with confidence and is not stated as a rule above.]

(8) Arrival Holding.

(a) Authorization. When an approach chart depicts an arrival holding pattern at an IAF or a feeder fix on an airway, that arrival holding pattern is not authorized unless the controlling facility assigns it.

(b) Alignment Holding. When a charted arrival holding pattern exists because the turn angle from the airway into the approach exceeds the angle the procedure allows for direct entry, and the controlling facility has not assigned the hold before the aircraft reaches the holding fix, the pilot SHOULD request the hold from the controlling facility. Once established on the inbound holding course with an approach clearance, the pilot begins the approach from that point.

EXAMPLE: Arrival Holding Required for Procedure Entry Chart note (plan view): "PROC NA VIA V212 EASTBOUND WITHOUT HOLDING AT FENTU. ATC CLNC REQD." CENTER: "Bandit Two Two, hold east of FENTU as published, expect further clearance three five past the hour." PILOT: "Hold east of FENTU as published, expect further clearance three five, Bandit Two Two."

Note: The chart note, fix name, and callsign above are generic placeholders illustrating the format used in the source AIM's own example (a note reading "Proc NA via V343 northeast bound without holding at JOXIT. ATC CLNC REQD."); they are not asserted as any real or currently charted procedure.

l. RF Legs. An RF leg is a constant-radius circular path around a defined turn center, beginning and ending at charted fixes. Not every aircraft's navigation system can fly an RF leg. Before accepting a clearance for a procedure containing an RF leg, the pilot MUST know whether the aircraft is capable of flying it.

When clearing an RNAV-equipped aircraft for a procedure containing an RF leg, the controlling facility WILL do so via a published transition, or by a direct clearance meeting the angle limits in k(6) above. The controlling facility WILL NOT clear an aircraft direct to a waypoint that begins or lies within an RF leg. The controlling facility MUST NOT assign a fix-crossing speed on an RF leg greater than the speed restriction charted for that leg.

Note: An RF leg's charted turn radius depends on the aircraft flying at or below the charted crossing speed; exceeding it changes the achievable turn radius and can carry the aircraft off the charted path.

EXAMPLE: RF Leg Restriction Chart depicts, in sequence: BEXAR (begins the RF leg), then PIVOT, then CROSS (ends the RF leg). Not permitted under this paragraph: a clearance direct to BEXAR, a vector or clearance to intercept the segment between BEXAR and CROSS, or a clearance direct to PIVOT.

Note: BEXAR, PIVOT, and CROSS above are generic placeholder fix names illustrating the restriction; the source AIM illustrates the same restriction using the fix names THIRD, TURNN, and FORTH on an unspecified example procedure.

m. Cancelling an Approach Clearance. When the controlling facility must cancel an approach clearance already issued, the controlling facility WILL state CANCEL APPROACH CLEARANCE, followed by any additional instruction (at the controlling facility's discretion: whether an additional instruction follows, and its content, depends on the traffic and airspace situation at the time).

EXAMPLE: Cancelling an Approach Clearance APPROACH: "Falcon Four Zero, cancel approach clearance, fly heading two seven zero, climb and maintain four thousand." PILOT: "Cancel approach clearance, heading two seven zero, climb and maintain four thousand, Falcon Four Zero."

Callsigns, fix names, altitudes, and frequencies in the examples throughout this paragraph are generic placeholders for illustration only and are not asserted as real-world or network-published values.

5.26 Instrument Approach Procedures

a. Purpose. This paragraph establishes the aircraft approach category system that fixes which set of minima a pilot flies to, the altitude a pilot holds while transitioning onto a published IAP from an unpublished route or radar vectors, the naming and inoperative-component conventions for a published IAP, the authorization needed to fly an IAP based on a privately owned navigation aid, and the pilot's notification duty when executing a missed approach.

b. Scope. This paragraph governs civilian, military, formation, and airline traffic alike; no category of traffic is exempt, and a military flight flying a published civil or DoD IAP follows this paragraph the same as any other flight. It applies to any IAP flown in the simulated environment, whether cleared by Approach Control, Center, or Tower. It does not govern how a chart depicts a procedure's minima lines, symbology, or required avionics, established in paragraph 5.24, Instrument Approach Procedure (IAP) Charts; it does not govern the phraseology or timing of the initial approach clearance itself, established in paragraph 5.25, Approach Clearance; it does not govern execution of the missed approach once initiated, established in paragraph 5.29, Missed Approach (a helicopter-specific missed-approach procedure, sourced from the AIM's 5-5-5, is outside this chapter's scope); and it does not restate the arrival routing a flight follows before reaching the approach environment, established in paragraph 5.21, Standard Terminal Arrival (STAR) Procedures. This paragraph does not address FAA certificate action, accident or incident investigation, or the administrative process for obtaining a special IAP's real-world FAA authorization; those are outside the simulated environment.

c. Controlled Terms. "Controlling facility" carries the meaning established in the Glossary; example blocks below label each transmission with the specific facility involved. "IFR" means Instrument Flight Rules. "MDA" (Minimum Descent Altitude) and "DA/DH" (Decision Altitude/Decision Height) are the Mean Sea Level (MSL) altitudes below which a pilot may not descend on a nonprecision, or a precision/APV (Approach with Vertical Guidance), procedure respectively without the required landing environment in sight. "Established," used of a pilot's position, means the aircraft is on a segment of a published route or the IAP itself, tracking its lateral and (where charted) vertical path; a pilot who has been assigned an altitude but has not yet joined such a segment is not established. "MVA" means Minimum Vectoring Altitude; "MIA" means Minimum IFR Altitude; both are floors used when assigning an altitude to an aircraft not yet established on a published segment. "IF" means Intermediate Fix; "IAF" means Initial Approach Fix; "OM" means Outer Marker. "VOR" means VHF Omnidirectional Range; "ILS" means Instrument Landing System; "LOC" means Localizer. "VREF" means the reference landing approach speed established for the aircraft; "VSO" means the aircraft's stalling speed, or minimum steady flight speed, in the landing configuration.

d. Approach Category.

(1) Each aircraft's approach category is fixed by its reference speed: VREF at the aircraft's maximum certificated landing weight, or, where VREF is not specified, 1.3 times VSO at that same weight.

Table 1: Aircraft Approach Categories by Reference Speed

#	Category	Speed Range
1	A	Less than 91 kt (knots)
2	B	91 kt or more but less than 121 kt
3	C	121 kt or more but less than 141 kt
4	D	141 kt or more but less than 166 kt
5	E	166 kt or more

Legend: kt = knots (indicated airspeed).

Note: Category is fixed by the aircraft's certificated reference speed at maximum landing weight, not by its actual weight or speed on a given flight, and does not change from approach to approach.

(2) The pilot MUST fly to minima published for the aircraft's own approach category or a higher category.

e. Category Selection at Higher Airspeed. When operating a circling or straight-in approach at a speed above the upper limit of the aircraft's own approach category (for example, in gusty wind, icing, or another non-normal condition), the pilot SHOULD use the minima published for the next higher category rather than the aircraft's own. A helicopter MAY use Category A minima regardless of its computed reference speed.

EXAMPLE: Higher-Category Minima at Elevated Speed A Category B airplane circling to land at 145 kt SHOULD use Category D minima. A Category A airplane, or a helicopter, flying a straight-in approach at 130 kt SHOULD use Category C minima.

f. Circling Approach Ground Track. When circling to land, the pilot MUST maneuver within the circling approach protected area published for the category and minima being flown, to retain the obstacle and terrain clearance that area's design provides.

(1) Bank angle, indicated airspeed, wind speed and direction, and pilot technique each affect the actual ground track flown, and together can carry the aircraft outside the protected area even when indicated airspeed itself stays within the category's limit.

Note: At 165 kt groundspeed, turn radius increases from about 4,194 ft using 30 degrees of bank to about 6,654 ft using 20 degrees of bank; a downwind leg of the circling pattern can also produce a groundspeed well above indicated airspeed, widening the turn further. A pilot circling at or near the upper end of a category's speed range should plan bank angle and pattern width with this margin in mind.

g. Descent Below Minimums. Where an MDA or a DA/DH applies to the approach being flown, the pilot MUST NOT descend below the MDA, or continue an approach below the DA/DH, unless the aircraft is continuously in a position from which a descent to landing on the intended runway can be made using a normal rate of descent and normal maneuvers. A flight operating to airline- or commuter-equivalent touchdown-zone standards (briefed every mission; no sim-wide default applies) additionally MUST NOT continue below the DA/DH unless that descent rate will put the aircraft down within the runway's touchdown zone.

h. Approach Clearance on Unpublished Routes and Vectors. When the controlling facility issues an approach clearance to a pilot operating on an unpublished route or under radar vectors, the pilot MUST maintain the last assigned altitude, in addition to any applicable IFR minimum altitude (14 CFR § 91.177), until established on a segment of a published route or the IAP. The controlling facility WILL assign, together with the clearance, an altitude that assures obstruction clearance from the point of clearance to that point of establishment.

EXAMPLE: Approach Clearance with Crossing Restriction APPROACH: "Cessna Four Two Bravo, cross Redding VOR at or above five thousand, cleared VOR Runway Three Four approach." PILOT: "Cross Redding VOR at or above five thousand, cleared VOR Runway Three Four approach, Cessna Four Two Bravo."

EXAMPLE: Approach Clearance with Vector to Final APPROACH: "November One Two Charlie, five miles from the outer marker, turn right heading three three zero, maintain two thousand until established on the localizer, cleared ILS Runway Three Six approach." PILOT: "Right heading three three zero, maintain two thousand until established on the localizer, cleared ILS Runway Three Six approach, November One Two Charlie."

Note: If the pilot is uncertain what altitude or routing the clearance requires, the pilot SHOULD request clarification from the controlling facility immediately rather than proceed on an assumption. An aircraft is not established while still below a published approach altitude; where the MVA or MIA allows, the controlling facility MAY assign an altitude below an IF or IAF's charted altitude, in which case the controlling facility also states the point past which the aircraft is established on the approach.

i. Multiple Approach Procedures at One Airport. When more than one IAP is authorized for an airport, the controlling facility MAY specify a particular procedure to expedite traffic. When a pilot cleared for a specified approach wants a different one instead, the pilot WILL notify the controlling facility immediately; the controlling facility MAY need to withhold the different approach until traffic conditions permit, except that a pilot in an emergency WILL be given priority. When a pilot is not familiar with the specific procedure assigned, the pilot SHOULD advise the controlling facility, and the controlling facility WILL provide the procedure's execution details.

EXAMPLE: Requesting a Different Approach APPROACH: "Skyhawk Nine One Delta, expect the ILS Runway Two Eight approach." PILOT: "Skyhawk Nine One Delta, we'd prefer the RNAV Runway Two Eight approach." APPROACH: "Skyhawk Nine One Delta, unable at this time, traffic; expect the RNAV approach in five miles."

j. Approach Naming and Inoperative Components. The controlling facility WILL identify an approach by its published name when issuing the clearance, even where a component navigation aid of that procedure (for example, an ILS glideslope) is inoperative or unreliable. When issuing the clearance for such a procedure, the controlling facility MUST also advise the pilot that the affected component is unusable, except where the procedure's own published title already covers that case (for example, an "ILS or LOC" title remains correctly named whether or not the glideslope is in service).

EXAMPLE: Clearance with Inoperative Component APPROACH: "Baron Six Two Kilo, glideslope out of service, cleared ILS Runway Two Seven approach." PILOT: "Cleared ILS Runway Two Seven approach, Baron Six Two Kilo."

Note: Because the title was not "ILS or LOC," the controlling facility's advisory in the example above puts the pilot on notice to fly the procedure to its localizer-only (LOC) minima rather than to the ILS DA.

k. Private Airfields and Privately Owned Navigation Aids. Before flying an IAP to a private airfield, or one based on a privately owned navigation aid, the pilot SHOULD obtain the owner's approval. An owner MAY turn off a privately owned navigation aid's signal for maintenance, energy conservation, or any other reason, without notice, and the controlling facility is not required to confirm a pilot's authorization for such a procedure or to know the aid's current status; the controlling facility WILL presume the pilot holds the required approval, and is aware of the procedure's details, once an IFR flight plan has been filed to that airport.

Note: In the real-world procedure this paragraph is drawn from, the pilot must also hold FAA authorization for the specific IAP (the source AIM's Special Instrument Approach Procedures section, outside this chapter's scope). The simulated environment has no equivalent certifying authority; where a network or mission requires prior coordination or authorization to fly a private-field or private-navaid procedure, that briefing governs and is not restated here as a clause.

l. Radar Fix Identification. When flying an IAP, the pilot SHOULD NOT rely on radar to identify a fix unless that fix is marked "RADAR" on the published procedure. The pilot MAY request radar identification of an OM; the controlling facility MAY be unable to provide it, whether from workload or because the fix is not on the controller's video map.

m. Missed Approach Notification. When the pilot initiates a missed approach, the pilot MUST advise the controlling facility and state the reason. When the controlling facility directs the missed approach instead, no additional reason report is required from the pilot. In either case, the pilot MUST comply with the published missed approach procedure for the IAP being executed unless the controlling facility directs otherwise; execution of the missed approach itself is established in paragraph 5.29, Missed Approach.

EXAMPLE: Pilot-Initiated Missed Approach PILOT: "Tower, Cherokee Seven Seven X-ray is going missed approach, runway not in sight." TOWER: "Cherokee Seven Seven X-ray, roger, fly published missed approach, contact Approach one two five point four."

Callsigns, fixes, altitudes, headings, and frequencies in the examples throughout this paragraph are generic placeholders for illustration only and are not asserted as real-world or network-published values.

5.27 Radar Approaches

This paragraph establishes procedures for a radar approach flown under Approach Control guidance: the Precision Approach Radar (PAR) approach, the Airport Surveillance Radar (ASR) approach, and the No-Gyro approach flown with either when the aircraft's heading instrument is unusable.

This paragraph does not establish approach and landing minimums (established in paragraph 5.28, Approach and Landing Minimums), missed approach procedures (established in paragraph 5.29, Missed Approach), radar monitoring of an independently flown instrument approach such as an ILS (a related topic of the source AIM's Chapter 5 not included in this contract), or the visual approach (established in paragraph 5.30, Visual Approach). It covers only the conduct of a radar approach once one is in progress.

Throughout this paragraph, Approach Control means the terminal radar facility providing PAR, ASR, or No-Gyro guidance, whatever its on-frequency callsign (for example, "Approach," a Radar Approach Control Facility (RAPCON) identifier, or, at many military and joint-use fields, GCA (Ground-Controlled Approach)). ATC is used only for the air traffic control system generally; where this paragraph means the facility flying the approach, it says Approach Control. PAR and ASR each name both a radar system (Precision Approach Radar; Airport Surveillance Radar) and, as used below, the approach flown with that system (a "PAR approach"; an "ASR approach" or "surveillance approach").

Note: A radar approach requires no airborne equipment beyond a functioning radio transmitter and receiver.

a. Approach types

(1) Two radar approaches exist: the PAR approach, which provides the pilot azimuth and elevation guidance, and the ASR approach, which provides azimuth guidance only. Paragraph f covers the No-Gyro approach, a vectoring technique usable during either.

(2) PAR and ASR minimums for a given procedure are published on separate pages of the Terminal Procedures Publication (TPP) (see paragraph 5.24, Instrument Approach Procedure (IAP) Charts, and paragraph 5.28, Approach and Landing Minimums). ASR minimums are higher than PAR minimums for the same runway.

Note: ASR minimums are higher because ASR provides azimuth guidance only. The pilot receives no controller-issued elevation guidance on an ASR approach and must fly the published descent profile using aircraft instruments alone.

Table 1. PAR and ASR Guidance Compared

Characteristic	PAR approach	ASR approach
Guidance axes	Azimuth and elevation	Azimuth only
Descent guidance	Continuous glidepath advisories to DH	One descent instruction (or step-down sequence) to MDA
Minimums	Lower	Higher
Range/position calls	At least once per NM	Once per mile of final; mile-by-mile recommended altitudes on request
Termination point	Landing threshold / DH	MAP

Legend: PAR = Precision Approach Radar. ASR = Airport Surveillance Radar. DH = Decision Height. MDA = Minimum Descent Altitude. MAP = Missed Approach Point. NM = nautical mile.

b. Approach availability

(1) On pilot request, Approach Control will provide a PAR or ASR approach, subject to equipment availability and traffic (at Approach Control's discretion). Approach Control may also offer a PAR or ASR approach without a request, to an aircraft in distress or to expedite traffic.

(2) Absent an ATC operational requirement, such as expediting traffic, or an unusual or emergency situation, Approach Control may decline a requested ASR approach. This limitation applies to the ASR approach only; it does not apply to the PAR approach.

c. Weather-minimums authority

(1) Accepting a PAR or ASR approach does not satisfy or waive the weather minimums published for the airport, or required under the pilot's operating rules, for the approach flown.

(2) When reported weather is below those minimums, the pilot retains sole authority to accept or decline the radar approach.

d. Precision Approach (PAR)

(1) Course and glidepath guidance. Approach Control will give heading vectors to align the aircraft with, and keep it on, the extended runway centerline. Approximately 10 to 30 seconds before the aircraft is expected to intercept the glidepath, Approach Control will advise the pilot to anticipate the intercept and will instruct the pilot to begin descent.

(2) Decision Height. If the pilot requests it, Approach Control will state the published Decision Height (DH) for the procedure. Otherwise, Approach Control will not state DH on frequency, and the pilot flies to the DH published on the IAP chart (paragraph 5.24).

(3) Deviation and trend calls. When the aircraft deviates above or below the glidepath, Approach Control will state the amount of deviation as "slightly" or "well." The pilot then adjusts the rate of descent or ascent to return to the glidepath. Approach Control may add a trend term, "rapidly" or "slowly," to describe how the deviation is changing.

(4) Range calls. Approach Control will state range from touchdown at least once per nautical mile (NM) of final approach.

(5) Safety-zone limits. When the aircraft is observed outside the specified azimuth or elevation safety-zone limits and continues to operate outside those limits, Approach Control will direct the pilot to execute a missed approach or to fly a specified course, unless the pilot has the runway environment (runway, approach lights, or comparable visual references) in sight.

(6) Guidance termination. Approach Control will provide azimuth and elevation guidance until the aircraft reaches the published DH. After the DH, Approach Control will continue advisory course and glidepath information until the aircraft passes the landing threshold, and will then advise the pilot of any deviation from runway centerline. Approach Control's radar service for the approach ends automatically once the approach is complete; no separate call is required.

Example: PAR Final Approach

Speaker	Transmission
Pilot (Example 12)	"Example Approach, Example One-Two, request the decision height for this approach."
Approach Control	"Example One-Two, decision height two hundred, three miles from touchdown, on course, prepare to descend."
Approach Control	"Example One-Two, on course, slightly above glidepath, coming down slowly."
Approach Control	"Example One-Two, one mile from touchdown, on course, on glidepath."
Approach Control	"Example One-Two, over landing threshold, contact tower one-one-niner-point-seven."

Required response: the pilot adjusts pitch and heading as advised and, on the final call, changes to the frequency given; no readback of course/glidepath advisories is required beyond normal acknowledgment.

Note: Callsign, altitude, and frequency values above are generic placeholders for illustration only, not published minimums or real facility data.

e. Surveillance Approach (ASR)

(1) Guidance provided. Approach Control will provide azimuth guidance only; no elevation guidance is provided.

(2) Descent to MDA. Approach Control will advise the pilot when to begin descent to the Minimum Descent Altitude (MDA), or, where the procedure has an intermediate step-down fix, to that fix's Minimum Crossing Altitude and subsequently to the MDA.

(3) Range and MAP calls. Approach Control will state the location of the Missed Approach Point (MAP) established for the procedure, and will state the aircraft's position at each mile of final approach, measured from the runway threshold (straight-in procedures), the landing area (helicopter point-in-space procedures), or the MAP, whichever the procedure specifies.

(4) Recommended altitudes. If the pilot requests mile-by-mile recommended altitudes, Approach Control will issue them based on the procedure's descent gradient, down to the last mile at or above the MDA. Absent such a request, Approach Control will issue only the descent instruction in (2) and the position and MAP calls in (3).

(5) Straight-in MDA timing. Approach Control will issue the published straight-in MDA to the pilot before the pilot begins descent.

(6) Circle-to-land MDA. When an ASR approach will terminate in a circle-to-land maneuver, the pilot must state the aircraft's approach category to Approach Control, and Approach Control will then provide the MDA appropriate to that category.

(7) Guidance termination at the MAP. Approach Control will provide guidance until the aircraft reaches the MAP. At the MAP, Approach Control will direct a missed approach unless the pilot has the runway, airport, or heliport in sight or, for a helicopter point-in-space approach, has established the visual reference the procedure prescribes.

(8) Early termination, civil aircraft only. For civil aircraft only, Approach Control may terminate guidance before the MAP when the pilot reports the runway, airport, heliport, or visual surface route in sight, or otherwise indicates that continued guidance is not required. For all other aircraft, including military aircraft, guidance continues to the MAP unless terminated under (9) or (10).

(9) Termination on pilot request. Whenever the pilot requests it, Approach Control will terminate guidance and direct a missed approach.

(10) Termination for safety. Whenever Approach Control determines that safe guidance for the remainder of the approach cannot be provided, Approach Control will terminate guidance and direct a missed approach, at any point in the approach.

(11) Automatic termination. Approach Control's radar service for the approach ends automatically once the approach is complete.

Example: ASR Approach to MDA

Speaker	Transmission
Approach Control	"Example Three-Four, three miles from the missed approach point, begin descent to eight hundred, minimum descent altitude."
Approach Control	"Example Three-Four, two miles from the missed approach point, on course."
Approach Control	"Example Three-Four, one mile from the missed approach point, on course."
Approach Control	"Example Three-Four, over the missed approach point, if not visual, execute missed approach."

Required response: the pilot descends and levels at the assigned altitude as advised, reports the runway/airport in sight if able (civil aircraft; see (8)), or executes the missed approach as directed.

Note: Callsign, distances, and altitude values above are generic placeholders for illustration only, not published minimums or real facility data.

f. No-Gyro Approach

(1) Availability. When the directional gyro or other stabilized compass becomes inoperative or inaccurate, the pilot should advise Approach Control and request a No-Gyro vector or approach. A pilot whose aircraft is not equipped with a directional gyro or other stabilized compass may likewise request a No-Gyro vector or approach.

(2) Turn instructions. Approach Control will direct each turn by transmitting "TURN LEFT" or "TURN RIGHT" to start it and "STOP TURN" to roll out. The pilot should begin or stop the turn immediately on receipt of the instruction and should turn at the standard rate (3 degrees per second, per the Pilot/Controller Glossary definition of STANDARD RATE TURN).

(3) Half-standard-rate turns on final. Once Approach Control has turned the aircraft onto final approach for a PAR or ASR approach, Approach Control will advise the pilot to turn at half the standard rate (1.5 degrees per second, derived from the rate in (2)) for the remainder of the approach.

Example: No-Gyro Vector

Speaker	Transmission
Pilot (Example 21)	"Approach, Example Two-One, directional gyro is unreliable, request a no-gyro approach."
Approach Control	"Example Two-One, roger, this will be a no-gyro surveillance approach, turn right."
Approach Control	"Example Two-One, stop turn."
Approach Control	"Example Two-One, turn left."
Approach Control	"Example Two-One, stop turn, on final approach course, turns will now be at half standard rate."

Required response: the pilot begins or stops the turn immediately on each instruction; no verbal readback is required beyond normal acknowledgment.

Note: The callsign above is a generic placeholder for illustration only.

Note: [VERIFY: whether this simulator's ATC client or voice-com tooling supports issuing "TURN LEFT/RIGHT" and "STOP TURN" as the exact phraseology, or whether the network's controller SOP substitutes different wording for the same procedure (briefed by the controlling facility if it differs).]

5.28 Approach and Landing Minimums

This paragraph establishes how a pilot determines and applies the landing minimums published for an instrument approach procedure, including the Runway Visual Range (RVR) conversion, the obstacle-clearance areas those minimums protect, and the conditions under which a straight-in, side-step, or circling landing may be flown. It applies to civil, military, and formation traffic making an instrument approach in the simulated environment.

This paragraph does not cover execution of the missed approach itself, established in paragraph 5.29, Missed Approach, and does not cover runway selection or separation during simultaneous parallel or converging approaches (a related topic of the source AIM's Chapter 5 not included in this contract).

a. Landing Minimums

Landing minimums are established under Title 14 of the Code of Federal Regulations (14 CFR) § 91.175. When ATC or the Automatic Terminal Information Service (ATIS) reports Runway Visual Range (RVR) for the runway in use, the pilot converts the reported RVR to an equivalent visibility in statute miles (SM) using Table 1 to compare against the visibility minimum published for the approach.

Table 1. Runway Visual Range (RVR) to Visibility Conversion

RVR (ft)	Visibility (SM)
1,600	1/4
2,400	1/2
3,200	5/8
4,000	3/4
4,500	7/8
5,000	1
6,000	1 1/4

Legend: RVR = Runway Visual Range; SM = statute miles; ft = feet.

When the reported RVR falls between two values listed in Table 1, the pilot will use the next higher listed RVR value to determine the equivalent visibility. The pilot must not interpolate between listed values.

EXAMPLE — Applying Table 1
Tower reports RVR 1,800 for the runway in use. Table 1 does not list 1,800 directly. The pilot rounds up to the next higher listed value, 2,400 RVR, which converts to 1/2 SM. The pilot compares 1/2 SM against the visibility minimum published for the approach and the aircraft's approach category (see paragraph e, Published Minimums and Aircraft Approach Category).

b. Obstacle Clearance

(1) Final Approach Obstacle Clearance Area. The final approach obstacle clearance area extends from the start of the final approach segment to the runway or to the missed approach point, whichever is farther along the approach path.

When a side-step maneuver is published for the approach (see paragraph d, Side-Step Maneuver Minimums), the final approach obstacle clearance area is widened to protect the side-step maneuver; this widening is already accounted for in the side-step minimums and requires no separate pilot action.

(2) Circling Approach Protected Area. The circling approach protected area is defined by arcs drawn from the ends of each usable runway. Terrain and obstacle clearance under the United States Standard for Terminal Instrument Procedures (TERPS) is assured within this area at or above the published circling minimum descent altitude (MDA), whether the pilot is flying straight-in, side-stepping, or circling to land.

Below the circling MDA, the pilot must see and avoid obstacles by visual reference; no protected obstacle clearance is assured below that altitude.

When a missed approach is initiated from a position outside the normal circling flight path, the pilot must complete any additional climb needed within the circling area, using normal maneuvers, before joining the published missed approach track (see paragraph 5.29.c, Circling Approach, Visual Reference Loss, for the technique flown to rejoin the missed approach course).

Note: An aircraft maneuvering to circle may be positioned outside the lateral or climb protection of the published missed approach segment. Climbing within the circling area first regains that protection before the aircraft proceeds on the missed approach track.

Note: A circling procedure amended since 2012 publishes a protected-area radius that accounts for the aircraft's true airspeed at the circling altitude in mean sea level (MSL) terms, rather than a single fixed radius per approach category, and is identified on the chart by a "negative C" symbol [VERIFY: effective date and exact FAA symbol name/rendering]. Both the older fixed-radius and the newer altitude-based radii are published in the U.S. Terminal Procedures Publication (TPP).

(3) Precision Obstacle Free Zone (POFZ). The POFZ is a volume of airspace 200 ft long and 800 ft wide, centered on the extended runway centerline at the runway threshold, at threshold elevation. The POFZ applies at every runway end served by a vertically-guided approach, including a displaced threshold.

When an aircraft flying a vertically-guided approach is within 2 nautical miles (NM) of the threshold and the reported ceiling is below 250 ft or the visibility is less than 3/4 SM (RVR below 4,000 ft), Tower must keep the POFZ clear of any aircraft or vehicle other than the landing aircraft.

An aircraft holding on a taxiway that intersects the POFZ must not allow its fuselage or tail to infringe on the POFZ. Its wings may extend into the POFZ.

When Tower cannot keep the POFZ clear under the triggering conditions above, the minimum authorized height above touchdown (HAT) and required visibility for the approach revert to 250 ft and 3/4 SM, respectively.

c. Straight-In Landing

Straight-in minimums are published for an approach when the final approach course is within 30 degrees of the runway centerline and a normal descent can be made from the charted altitude to the runway. Straight-in minimums are not published, and circling minimums apply instead, when either condition is not met.

When the pilot has the landing runway in sight with sufficient time to make a normal approach to landing, and Tower or Approach has cleared the aircraft to land on that runway, the pilot may land straight-in without circling, even though only circling minimums are published for that runway or category. When those conditions are not met, the pilot circles to land using the published circling minimums.

The pilot may instead advise Approach or Tower of an intent to circle rather than land straight-in.

Note: The exact wording of the landing clearance ("cleared to land," "cleared for the approach," or similar) does not change the pilot's option to land straight-in under this paragraph. The controlling fact is that the aircraft has been cleared to land on the runway already in sight.

EXAMPLE — Straight-In Landing on a Circling-Only Procedure
Sender/Condition: Approach, when vectoring the aircraft to the approach.
Approach: "Bugsmasher One Two Alpha Bravo, fly heading zero niner zero, vectors RNAV Runway Two Four approach, circle to land Runway One Eight."
Pilot: "Heading zero niner zero, vectors RNAV Two Four, circle One Eight, One Two Alpha Bravo."
[The pilot subsequently has Runway Two Four in sight with sufficient time for a normal approach and is on Tower's frequency.]
Sender/Condition: Pilot, on acquiring the runway environment.
Pilot: "One Two Alpha Bravo has Runway Two Four in sight, request straight-in."
Required response: Tower, landing clearance for the requested runway.
Tower: "One Two Alpha Bravo, cleared to land Runway Two Four."
Note: Callsign, heading, and runway are illustrative placeholders, not asserted AIM values. RNAV = Area Navigation.

d. Side-Step Maneuver Minimums

Published minimums for a side-step to the adjacent runway are normally higher than the minimums for the primary runway. The pilot will use the side-step minimums, not the primary-runway minimums, when performing the maneuver.

e. Published Minimums and Aircraft Approach Category

Approach minimums are published by aircraft approach category and consist of a minimum altitude and a required visibility, both determined under TERPS criteria (see the Pilot/Controller Glossary for the aircraft approach category definitions; the category system itself is established in paragraph 5.26.d, Instrument Approach Procedures). The minimum altitude is decision altitude/decision height (DA/DH) for a vertically-guided approach, or MDA for a non-vertically-guided or circling approach.

When a nonprecision approach has a stepdown fix in the final approach segment, the chart may publish two lines of minimums: one applicable when the pilot identifies the stepdown fix, and a higher line applicable when the pilot does not. The pilot will use the line that matches whether the stepdown fix is actually identified.

When a procedure permits use of an alternate (second) altimeter source, the chart may similarly publish two lines of minimums keyed to which altimeter source is in use. The pilot will use the line that matches the altimeter source actually in use.

Note: A procedure with both a stepdown fix and an alternate altimeter source publishes minimums addressing both factors together; the pilot checks fix-identification status and altimeter source together to select the correct line.

f. Circling Approach Procedures

(1) Charted Circling Restrictions. A charted circling restriction (for example, "Circling NA east of Runway 17-35" [illustrative chart-note format, not an asserted real procedure]) limits maneuvering to the unrestricted sector; the restriction may apply only to specific aircraft approach categories or only to day or night operations, as charted.

When the approach chart carries a circling restriction, the pilot must not maneuver in the restricted sector, subject to any category or day/night limitation stated on the chart.

(2) Circling at Towered Airports. At a towered airport, the pilot will comply with Tower's instructions during the circling maneuver. A Tower instruction or landing clearance does not authorize maneuvering into a sector prohibited by a charted circling restriction; the charted restriction still applies.

EXAMPLE — Complying with a Charted Circling Restriction
Sender/Condition: Tower, after the aircraft reports the airport in sight for a charted circling approach.
Tower: "Cessna Four Five Charlie Delta, circle to land Runway Three Five, report left base."
Pilot: "Circle to land Runway Three Five, wilco, Four Five Charlie Delta."
Note: If the chart restricts circling east of Runway 17-35, the pilot maneuvers only west of the runway to reach the reported left base for Runway 35; Tower's request to report left base does not authorize entering the restricted sector.

(3) Circling at Non-Towered Airports. At a non-towered airport, the pilot will turn in the traffic pattern direction prescribed by 14 CFR § 91.126(b) unless a charted circling restriction requires the opposite direction, in which case the charted restriction governs.

The pilot should overfly the airport, remaining at or above the circling altitude, to check wind indicators and other traffic before entering the pattern.

(4) Circling Area and Traffic Awareness. While circling, the pilot will remain within the circling protected-area radius published in the U.S. TPP for the aircraft's approach category and the MSL circling altitude flown, and will maintain visual awareness for other traffic in the pattern.

When maneuvering to a base or downwind leg, the pilot should account for existing weather, VFR traffic flow, the altitude loss required using a normal rate of descent and normal maneuvers, and any charted circling restriction, before committing to the turn.

(5) Missed Approach Point and Prohibited Circling. For an approach flown to landing with vertical guidance (not circling), the missed approach point is the DA/DH. For a non-vertically-guided approach and for circling, the missed approach point is established by timing from the final approach fix, by a fix, by a navigational aid (NAVAID), or by a waypoint, as published.

Circling must not be flown from a GBAS Landing System (GLS) approach, from an Instrument Landing System (ILS) approach without a published localizer-only line of minima, or from a Global Positioning System (GPS)-based Area Navigation approach (RNAV (GPS)) without a published Lateral Navigation (LNAV) line of minima.

g. Instrument Approaches at Military Airfields

At a military airfield, the pilot will comply with the instrument approach procedures and minimums approved by the military agency having jurisdiction over that airfield, even where they differ from civil TERPS-based procedures.

EXAMPLE — Approach to a Military-Controlled Airfield
Sender/Condition: Approach (military-run facility), issuing the approach clearance.
Approach: "November Three Four X-ray Yankee, cross NITRO at or above three thousand, cleared ILS Runway Zero One approach, contact Tower one two six point two at NITRO."
Pilot: "Cross NITRO at or above three thousand, cleared ILS Zero One, Tower one two six point two at NITRO, Three Four X-ray Yankee."
Note: Fix name, altitude, runway, and frequency are illustrative placeholders. The published procedure and minimums for the airfield govern regardless of how they compare to a civil TERPS procedure for a similar runway.

5.29 Missed Approach

This paragraph establishes what the pilot and the controlling facility each do when an instrument approach cannot be completed to a landing: compliance with the published or an alternate MISSED APPROACH procedure, the conditions under which the published MISSED APPROACH protects the aircraft from obstacles, the technique for rejoining the MISSED APPROACH course after losing visual reference while circling, radar-vectored and NOTAM-based alternate MISSED APPROACH handling, and the clearance the pilot obtains after going missed. It applies to civilian, military, formation, and airline traffic alike, flying any instrument approach procedure (IAP) in the simulated environment.

This paragraph does not establish the pilot's duty to advise the controlling facility and state the reason for a pilot-initiated MISSED APPROACH, established in paragraph 5.26.m, Missed Approach Notification. It does not establish the obstacle-clearance basis of the circling approach protected area itself, established in paragraph 5.28.b.(2), Circling Approach Protected Area; this paragraph addresses only the climb and course the pilot flies once a MISSED APPROACH is under way.

Note: Throughout this paragraph, "controlling facility" carries the meaning established in the Glossary: Approach Control, Center, or Tower, whichever is providing ATC service to the aircraft executing the MISSED APPROACH. Where a clause depends on radar service being provided, only Approach Control or Center can be the controlling facility, because Tower does not provide radar service.

a. Missed Approach Point

Upon reaching the MISSED APPROACH POINT (MAP) published for the approach in use, if a landing cannot be completed, the pilot must fly the MISSED APPROACH procedure published for that approach, or, when the controlling facility has specified one, the alternate MISSED APPROACH procedure instead.

Note: This paragraph governs compliance with the procedure once at the MAP. The separate duty to advise the controlling facility and, if the MISSED APPROACH is pilot-initiated, state the reason, is established in paragraph 5.26.m, Missed Approach Notification.

b. Obstacle Protection and Climb Gradient

(1) To remain within the obstacle protection built into the published MISSED APPROACH, the pilot must initiate it at or above the MAP and at or above the minimum descent altitude (MDA) or decision altitude/decision height (DA/DH) published for the approach in use.

(2) The published MISSED APPROACH assumes a climb gradient of at least 200 feet per nautical mile (NM), or, for a helicopter procedure, at least 400 feet per NM. Where the approach chart publishes a higher climb gradient, the pilot must fly that charted gradient to the altitude or fix at which the chart states the higher gradient ends.

(3) Before beginning the approach, the pilot must determine that the aircraft can meet the climb gradient required for the MISSED APPROACH. A higher ground speed requires a higher rate of climb, in feet per minute, to hold the same gradient in feet per NM.

(4) If the pilot begins the MISSED APPROACH before reaching the MAP, the pilot should continue on the published approach course to the MAP, at or above the MDA or DA/DH, before turning, unless the controlling facility clears the pilot to do otherwise.

Table 1. Missed Approach Climb Gradient

#	Procedure Type	Minimum Climb Gradient
1	Standard (non-helicopter) IAP	200 ft/NM
2	Helicopter IAP	400 ft/NM

Legend: IAP = Instrument Approach Procedure. ft/NM = feet per nautical mile.

Note: A real-world approach chart prints a table converting climb gradient (ft/NM) to climb rate (ft/min) by ground speed. [VERIFY: whether this simulator's chart provider publishes an equivalent conversion table and, if so, where; its location and format are not standardized across chart sets.]

c. Circling Approach, Visual Reference Loss

When the pilot loses visual reference while circling to land, the pilot must fly the MISSED APPROACH procedure published for the approach in use, or the alternate MISSED APPROACH procedure specified by the controlling facility. To rejoin the published MISSED APPROACH course, the pilot should make an initial climbing turn toward the landing runway, continuing the turn until established on the MISSED APPROACH course; because circling can be entered from more than one side of the runway, the turn actually flown depends on the aircraft's position at the moment visual reference is lost.

Note: This turn keeps the aircraft within the circling and MISSED APPROACH obstruction clearance areas. The obstacle-clearance basis for remaining within the circling protected area while climbing is established in paragraph 5.28.b.(2), Circling Approach Protected Area.

d. Radar-Vectored Missed Approach

(1) Where Approach Control or Center provides radar service for the approach in use, the pilot should expect radar vectors in place of the published MISSED APPROACH procedure.

(2) When the controlling facility issues a radar vector during a MISSED APPROACH, the pilot must fly the assigned vector in place of the published MISSED APPROACH procedure.

e. Alternate Missed Approach Procedures

(1) At a location with a preplanned alternate MISSED APPROACH procedure, the approach chart depicts the alternate's holding pattern without printing the alternate procedure's text.

Note: The alternate procedure's text is left off the chart so the alternate is not confused with the primary MISSED APPROACH procedure. The holding pattern is still charted for situational awareness.

(2) The controlling facility activates the alternate MISSED APPROACH procedure by Notice to Air Missions (NOTAM), stating the procedure and any equipment it requires beyond the published approach. If a navigation aid (NAVAID) used in the primary MISSED APPROACH procedure fails during the approach, the controlling facility instead issues the alternate MISSED APPROACH procedure by instruction on frequency.

(3) If the controlling facility issues the alternate MISSED APPROACH procedure before the pilot begins the approach, the pilot must either accept the approach with the alternate MISSED APPROACH procedure as issued, request a different approach, or coordinate a different course of action with the controlling facility.

(4) If the controlling facility issues the alternate MISSED APPROACH procedure after the pilot begins the approach, the pilot may decline the alternate when it requires equipment not required for the published approach.

Example: ATC-Issued Alternate Missed Approach

Speaker	Transmission
Pilot (Viper Two-One flight lead)	"Approach, Viper Two-One flight, request the ILS Runway Zero-Niner approach."
Approach Control	"Viper Two-One flight, primary missed approach NAVAID is out of service, alternate missed approach in effect via the One-Two-Zero radial, VOR/DME required, cleared ILS Runway Zero-Niner approach."
Pilot (Viper Two-One flight lead)	"Viper Two-One flight has VOR/DME, cleared ILS Zero-Niner, wilco."

Required response: the pilot accepts the approach as cleared, requests a different approach, or coordinates a different course of action with Approach Control, per (3) above.

Note: Callsign, runway, radial, and equipment above are generic placeholders for illustration only, not asserted real-world or network values.

f. Post-Missed-Approach Clearance

After executing a MISSED APPROACH, the pilot must request clearance from the controlling facility for the next specific action, for example another approach at the same airport or diversion to an alternate airport.

Example: Post-Missed-Approach Clearance Request

Speaker	Transmission
Pilot (Jetlink Two-Zero-Five)	"Approach, Jetlink Two-Zero-Five, missed approach, request the RNAV Runway One-Eight approach."
Approach Control	"Jetlink Two-Zero-Five, roger, fly heading zero-niner-zero, climb and maintain four thousand, vectors for the RNAV Runway One-Eight approach."

Required response: Approach Control issues heading, altitude, and routing for the requested action; the pilot reads back the clearance.

Note: Callsign, heading, altitude, and runway above are generic placeholders for illustration only, not asserted real-world or network values.

g. Published Missed Approach Altitude

(1) Before deviating from the published MISSED APPROACH lateral course, the pilot must climb to the altitude published in the MISSED APPROACH procedure for the approach in use.

Note: Departing the published MISSED APPROACH course before reaching that altitude can leave the aircraft below the terrain and obstacle clearance the procedure provides, particularly where the controlling facility does not provide radar service.

(2) The altitude published in the MISSED APPROACH procedure is a minimum; the controlling facility may assign a higher altitude, under the clearance in paragraph f, before the pilot proceeds to the initial approach fix (IAF) or to an alternate airport.

h. Scope of Missed Approach Protection

(1) A clearance for an instrument approach procedure includes clearance to fly the published MISSED APPROACH procedure for that approach, unless the controlling facility instructs otherwise.

(2) The obstacle protection and climb gradient in paragraph b apply only under the conditions stated there (see Table 1). That protection does not extend to a MISSED APPROACH begun during a circling maneuver (see paragraph c), at a point other than the MAP, or below the MDA or DA/DH. The controlling facility's separation from other traffic is likewise not assured in those cases.

(3) Before beginning the approach, the pilot must determine the action to take if the pilot must go missed at a point other than the MAP or below the MDA or DA/DH, accounting for aircraft performance, aircraft position, charted obstacles, and other traffic (briefed every mission; no standing default beyond paragraph h.(2)).

5.30 Visual Approach

a. Purpose. This paragraph establishes the sight and weather conditions required for a visual approach, the content and phraseology of a visual approach clearance, separation responsibility between a controlling facility and a pilot on a visual approach, simultaneous visual approaches to parallel, intersecting, or converging runways, go-around procedures, and the effect of a visual approach clearance on the underlying IFR flight plan.

b. Scope. This paragraph governs any pilot on an IFR flight plan who is cleared for a visual approach, whether civil, military, formation, or airline traffic; no category of traffic is exempt. It applies at towered and non-towered airports alike. It does not establish a Charted Visual Flight Procedure (CVFP) (a related topic of the source AIM's Chapter 5 not included in this contract); the contact approach, established in paragraph 5.31, Contact Approach; the routing or phraseology of an instrument approach clearance generally, established in paragraph 5.25, Approach Clearance; or the general vectoring, sequencing, and handoff role of Approach Control, established in paragraph 5.22, Approach Control.

c. Controlled Terms. "Controlling facility" carries the meaning established in the Glossary; the roles of Approach and Center are established in paragraph 5.22, Approach Control. "Tower" means the local control position at a towered airport, which assigns landing clearances and go-around instructions once an aircraft is established on a visual approach. "VMC" means Visual Meteorological Conditions. "Ceiling" means the height of the lowest broken or overcast cloud layer, or the vertical visibility into an obscuration, reported as height above ground level (AGL) at the reporting station. "Advisory frequency" means the Common Traffic Advisory Frequency (CTAF), UNICOM, or FSS airport advisory frequency published for a non-towered airport. "RNAV" means Area Navigation. "ILS" means Instrument Landing System.

d. Definition, Sight Requirement, and Weather Minimums. A visual approach is an IFR procedure flown in VMC: it lets a pilot proceed visually and clear of clouds to the airport while remaining on the IFR flight plan for separation purposes. A maneuver is not a visual approach unless the controlling facility authorizes and controls it; a pilot does not self-initiate one.

Before accepting a visual approach clearance, the pilot MUST have either the destination airport or the specific preceding aircraft to be followed in sight. For the controlling facility to authorize a visual approach, the weather reported at the destination airport MUST show a ceiling at or above 1,000 feet AGL and visibility of 3 statute miles (SM) or greater. Whenever it judges doing so operationally beneficial (for example, to shorten the flight path or reduce workload), the controlling facility MAY authorize a visual approach (at the controlling facility's discretion; no fixed criteria define "operationally beneficial").

While flying the visual segment, the pilot MUST only remain clear of clouds and need not maintain the VFR cloud-clearance distances of 14 CFR 91.155, unless the pilot's own operating rules require more (briefed every mission; no sim-wide default beyond "clear of clouds" applies). The pilot SHOULD use available navigation aids to help align with the runway laterally and vertically during that segment.

Note: This relief from the normal VFR cloud-clearance distances applies because a visual approach remains an IFR procedure conducted in VMC, not a VFR clearance; 14 CFR 91.155 itself is not otherwise addressed by this paragraph.

EXAMPLE: Visual Approach Clearance With the Airport in Sight Approach: "Cessna Six Two Bravo, [airport] Airport, one o'clock, one zero miles, cleared visual approach Runway Two Seven." Pilot: "Airport in sight, cleared visual approach Runway Two Seven, Cessna Six Two Bravo."

EXAMPLE: Visual Approach Clearance Following Traffic Approach: "Delta Eleven Twenty, traffic is a Boeing Seven Thirty Seven, one o'clock, four miles, on a four-mile final Runway Two Seven, follow that traffic, cleared visual approach Runway Two Seven." Pilot: "Traffic in sight, cleared visual approach Runway Two Seven, Delta Eleven Twenty."

e. Authorization Without Weather Reporting. When the destination airport has no weather reporting service, the controlling facility WILL advise the pilot that weather is not available. Given that advisory, the controlling facility MAY still authorize a visual approach if reasonable assurance exists that the airport's weather meets the ceiling and visibility minimums in paragraph d. above (for example, from an area forecast, a nearby station's reported weather, or a Pilot Report (PIREP)). Otherwise, the controlling facility does not authorize a visual approach to that airport.

EXAMPLE: Visual Approach Authorized Without Local Weather Reporting Approach: "Cessna Six Two Bravo, [airport] weather not available, area reports indicate a ceiling above one thousand and visibility better than three miles, cleared visual approach Runway One Eight." Pilot: "Cleared visual approach Runway One Eight, Cessna Six Two Bravo."

f. Simultaneous Visual Approaches to Parallel, Intersecting, or Converging Runways. At an airport with an operating control tower, the controlling facility MAY authorize a visual approach to one runway while other aircraft conduct IFR or VFR approaches to a parallel, intersecting, or converging runway. Before doing so, the controlling facility MUST advise all aircraft involved that traffic is operating to the other runway; this advisory MAY be given individually by radio or published as an ATIS remark.

(1) For parallel runways separated by less than 2,500 feet, the controlling facility WILL provide the applicable separation standard until the trailing aircraft's pilot reports the leading aircraft in sight on the adjacent parallel and accepts visual separation from it.

(2) For parallel runways separated by 2,500 feet or more but less than 4,300 feet, the controlling facility WILL provide the applicable separation standard until both aircraft have been issued their respective approach clearances, one pilot has acknowledged a visual approach clearance and the other pilot has acknowledged a visual or instrument approach clearance, and each aircraft is established on an assigned heading, a direct course to a fix, or an RNAV or instrument approach procedure that will intercept the extended runway centerline at an angle of 30 degrees or less.

(3) For parallel runways separated by 4,300 feet or more, the controlling facility WILL provide the applicable separation standard until one aircraft has been issued and its pilot has acknowledged a visual approach clearance, and each aircraft is assigned a heading, a direct course to a fix, or an RNAV or instrument approach procedure that will allow it to intercept the extended runway centerline at an angle of 30 degrees or less.

Table 1: Separation Requirement by Parallel Runway Spacing

#	Runway Centerline Separation	Separation Standard Provided Until
1	Less than 2,500 ft	Trailing pilot reports leading aircraft in sight and accepts visual separation
2	2,500 ft up to 4,300 ft	Both approach clearances issued and acknowledged, and both aircraft established on a heading, direct course, or RNAV/instrument procedure intercepting the extended centerline at 30° or less
3	4,300 ft or more	One visual approach clearance issued and acknowledged, and each aircraft assigned a heading, direct course, or RNAV/instrument procedure intercepting the extended centerline at 30° or less

Legend: ft = feet; RNAV = Area Navigation; ° = degrees.

Note: The 30-degree intercept-angle limit exists to reduce the chance of overshooting the final approach course and to prevent two aircraft from ending up side by side, one banked away from the other, during the turn onto final.

EXAMPLE: Advisory for Simultaneous Visual Approaches to Parallel Runways ATIS remark: "Visual approaches in use, Runways Two Seven Left and Two Seven Right." Approach: "Cessna Six Two Bravo, traffic is an Airbus A320 for the parallel runway, Two Seven Right, cleared visual approach Runway Two Seven Left." Pilot: "Traffic, cleared visual approach Runway Two Seven Left, Cessna Six Two Bravo."

g. Visual Approach Clearance Content. At a towered airport, the controlling facility's visual approach clearance WILL include an assigned runway. At an airport without an operating control tower, or where a part-time tower is closed, the controlling facility WILL issue a visual approach clearance to the airport only, without an assigned runway.

h. Separation Responsibility When Following Traffic. When a pilot has the destination airport in sight but not the aircraft to be followed, the controlling facility MAY still clear the aircraft for a visual approach; the controlling facility continues to provide IFR separation and wake-turbulence separation from the traffic ahead. When a pilot has the preceding aircraft in sight and accepts a visual approach clearance to follow it, the pilot assumes responsibility for the approach interval and wake-turbulence separation from that aircraft; the pilot MUST maintain a safe approach interval and adequate wake-turbulence separation from it for the remainder of the approach.

i. Go-Around Procedures. A visual approach is not an Instrument Approach Procedure (IAP) and has no missed approach segment. When a go-around becomes necessary for any reason at a towered airport, Tower WILL issue an appropriate clearance or instruction, either to reenter the traffic pattern for landing or to proceed as otherwise instructed. While complying with that instruction, the pilot MUST maintain terrain and obstruction avoidance until reaching an ATC-assigned altitude, if one has been issued. During the go-around, the controlling facility WILL provide IFR separation, or visual separation, from other IFR traffic.

When a go-around becomes necessary at an airport without an operating control tower, the pilot MUST remain clear of clouds and complete the landing as soon as possible. If a landing cannot be completed, the pilot MUST remain clear of clouds and contact the controlling facility as soon as possible for further clearance. Throughout this sequence, the controlling facility WILL continue to provide separation from other IFR traffic.

EXAMPLE: Go-Around Instruction at a Towered Airport Tower: "Cessna Six Two Bravo, go around, fly runway heading, climb and maintain three thousand." Pilot: "Going around, runway heading, climb and maintain three thousand, Cessna Six Two Bravo."

j. Notification When a Visual Approach Is Not Desired. Upon determining that a visual approach is not wanted, the pilot WILL advise the controlling facility without delay.

Note: A visual approach shortens the flight path and reduces pilot and controller workload compared with an instrument approach, which is why the controlling facility offers one whenever conditions and traffic permit; prompt notice under this paragraph lets the controlling facility arrange an instrument approach or alternate routing instead.

EXAMPLE: Declining a Visual Approach Approach: "Cessna Six Two Bravo, cleared visual approach Runway Two Seven." Pilot: "Negative on the visual, Cessna Six Two Bravo, request the ILS Runway Two Seven approach." Approach: "Cessna Six Two Bravo, roger, fly heading two five zero, vectors ILS Runway Two Seven approach."

k. IFR Flight Plan Status. A visual approach clearance is an IFR authorization; accepting one does not change the pilot's responsibility to close the IFR flight plan, established in paragraph 5.8, Canceling IFR Flight Plan.

l. Termination of Radar Service on Frequency Change. When the controlling facility instructs a pilot on a visual approach to a non-towered airport to change to the airport's advisory frequency (CTAF, UNICOM, or FSS airport advisory frequency, as published), radar service WILL terminate automatically at that point; the controlling facility does not issue a separate advisory of the termination.

EXAMPLE: Frequency Change Ending Radar Service Approach: "Cessna Six Two Bravo, radar service terminated, change to advisory frequency approved, report your cancellation or landing on this frequency." Pilot: "Change to advisory approved, Cessna Six Two Bravo."

Callsigns, headings, distances, altitudes, runway numbers, and frequencies in the examples throughout this paragraph are generic placeholders for illustration only and are not asserted as real-world or network-published values.

5.31 Contact Approach

This paragraph establishes when a pilot may request, and when the controlling facility may authorize, a CONTACT APPROACH as an alternative to the standard or special instrument approach procedure otherwise applicable to an IFR arrival; the conditions the controlling facility confirms before issuing the clearance; and the responsibilities the pilot assumes while executing it.

This paragraph does not establish the general conduct of a standard or special instrument approach procedure, or the visual approach (established in paragraph 5.30, Visual Approach). A CONTACT APPROACH is a distinct clearance type from each of those, and applies equally to civil, military, and formation traffic operating on an IFR flight plan.

Note: Throughout this paragraph, "controlling facility" carries the meaning established in the Glossary.

a. Pilot Request

When operating on an IFR flight plan, remaining clear of clouds, maintaining at least 1 mile flight visibility, and reasonably expecting to continue to the destination airport in those conditions, a pilot may request a CONTACT APPROACH from the controlling facility. Otherwise, the pilot flies the standard or special instrument approach procedure normally applicable to the arrival.

A CONTACT APPROACH is available only when the pilot requests it; the controlling facility must not initiate one.

Note: Flight visibility is the pilot's own in-flight judgment; no facility reports or verifies it. This is distinct from the ground visibility in paragraph b.(1), which the controlling facility obtains from the reported weather for the destination airport.

Example: Requesting a Contact Approach

Speaker	Transmission
Pilot (November One Two Alpha Bravo)	"Example Approach, November One Two Alpha Bravo, request contact approach, Riverside Muni."
Approach	"November One Two Alpha Bravo, roger, cleared contact approach, Riverside Muni, report the field in sight."

Required response: the pilot reads back the clearance.

Note: Callsign and airport name above are generic placeholders for illustration only, not asserted real-world or network values.

b. Authorization Conditions

Before authorizing a CONTACT APPROACH, the controlling facility will confirm that:

(1) the destination airport's reported ground visibility is at least 1 statute mile (SM);

(2) the destination airport has a published, functioning standard or special Instrument Approach Procedure (IAP); and

(3) the aircraft remains separated from other IFR or Special Visual Flight Rules (Special VFR) traffic; the controlling facility will continue to apply standard separation, and a CONTACT APPROACH does not reduce or waive it.

When any condition in this paragraph is not met, the controlling facility must not authorize the CONTACT APPROACH and will instead issue the standard or special instrument approach clearance otherwise applicable to the arrival.

Table 1. Contact Approach Eligibility and Authorization Conditions

#	Condition	Required Value	Confirmed By
1	Pilot's in-flight visibility and cloud clearance	At least 1 mile flight visibility, clear of clouds	Pilot
2	Destination reported ground visibility	At least 1 SM	Controlling facility
3	Destination instrument approach procedure	Published, functioning standard or special IAP	Controlling facility
4	Traffic separation	Standard IFR/Special VFR separation maintained	Controlling facility

Legend: SM = statute mile. IAP = Instrument Approach Procedure. IFR = Instrument Flight Rules. VFR = Visual Flight Rules.

c. Clearance Restrictions

When the controlling facility includes an altitude or routing restriction in a CONTACT APPROACH clearance, the controlling facility will also state the alternative procedure the pilot is to follow if unable to comply with the restriction, and will instruct the pilot to advise if that alternative procedure is used. When no restriction is included, the pilot proceeds to the destination via own navigation, remaining clear of clouds, and lands using normal precautions.

Example: Contact Approach Clearance with Restriction

Speaker	Transmission
Pilot (November Three Four X-ray Yankee)	"Example Center, November Three Four X-ray Yankee, request contact approach, Riverside Muni."
Center	"Three Four X-ray Yankee, cleared contact approach, Riverside Muni, maintain at or below three thousand until established, if not possible hold as published at ROMEO and advise."
Pilot	"Cleared contact approach, at or below three thousand until established, if not possible hold at ROMEO and advise, Three Four X-ray Yankee."

Required response: the pilot reads back the clearance, including the restriction and the stated alternative.

Note: Callsign, airport, altitude, and fix name above are generic placeholders for illustration only, not asserted real-world or network values.

d. Execution and Responsibility

Once cleared for a CONTACT APPROACH, the pilot must maintain the aircraft's own obstruction and terrain clearance for the remainder of the approach; the controlling facility does not provide obstacle clearance based on the pilot's own navigation.

Once the controlling facility instructs the pilot to change to the destination airport's advisory frequency, the controlling facility's radar service to that aircraft terminates automatically; no further separation service from the controlling facility is provided beyond that point.

Note: A CONTACT APPROACH is not a substitute for a published instrument approach procedure at an airport that has none. Paragraph b.(2) requires a published, functioning IAP at the destination before the controlling facility may authorize the clearance.

5.32 Overhead Approach Maneuver

a. Purpose. This paragraph establishes the OVERHEAD MANEUVER: the conditions under which a pilot on an IFR flight plan may request it, the fallback to a standard traffic pattern when it is unavailable or unauthorized, the change in the flight's IFR/VFR status the maneuver produces, and the calls exchanged between the pilot and the controlling facility while flying it.

b. Scope. This paragraph governs the OVERHEAD MANEUVER as an ATC-authorized VFR pattern flown from an IFR flight plan at an airport with an established overhead maneuver pattern. It applies to civil, military, formation, and airline traffic alike; no category of traffic is exempt, and a military or formation flight requesting the maneuver follows the same authorization and reporting rules as any other flight. It does not establish the general procedure, methods, or phraseology for canceling an IFR flight plan, established in paragraph 5.8, Canceling IFR Flight Plan, except where this paragraph states a rule specific to the OVERHEAD MANEUVER that modifies that general procedure. It does not establish the conduct of the standard rectangular traffic pattern flown when the OVERHEAD MANEUVER is unavailable or unauthorized, established in paragraph 4.21, Traffic Patterns. It does not establish an instrument approach procedure; the OVERHEAD MANEUVER is not one and does not substitute for one.

c. Controlled terms. "Controlling facility" means Tower, or, at an airport without a functioning control tower, whichever of Approach or Center is currently providing IFR service to the flight, the Tower-primary variant of the term established in the Glossary. "OVERHEAD MANEUVER" is the controlled name for the maneuver established in this paragraph, as flown by a specific flight; "overhead maneuver pattern" (not capitalized) is the distinct concept of an airport's own published procedure for the maneuver, which must exist before a controlling facility may authorize any flight to fly it (paragraph e). "INITIAL POINT" is the point at which the flight begins the INITIAL APPROACH leg; "BREAK POINT" is the point at which the flight begins the first 180-degree turn of the maneuver; "ROLL OUT" is the point at which the flight completes the second 180-degree turn and aligns with the runway. "VMC" means Visual Meteorological Conditions. "NM" means nautical mile.

d. Eligibility. When operating on an IFR flight plan and in VMC, the pilot may request OVERHEAD MANEUVER authorization from the controlling facility for the destination airport. Otherwise, the OVERHEAD MANEUVER is not available, and the pilot flies the standard or instrument arrival procedure otherwise applicable.

Note: The OVERHEAD MANEUVER is a VFR pattern flown from an IFR flight plan; it is not an instrument approach procedure.

e. Pattern Availability. The OVERHEAD MANEUVER exists only at an airport for which an overhead maneuver pattern has been established; which airports have one, and that pattern's own published pattern altitude, turn direction, and BREAK POINT, are briefed every mission from that airport's published procedures. When no overhead maneuver pattern is established for the destination airport, or when the controlling facility does not authorize the maneuver on request, the pilot will fly the standard rectangular traffic pattern established in paragraph 4.21, Traffic Patterns, instead. An established overhead maneuver pattern does not by itself guarantee authorization on a given arrival.

f. Flight Plan Status at a Towered Airport. On reaching the INITIAL POINT of an authorized OVERHEAD MANEUVER at an airport with a functioning control tower, the flight becomes VFR and its IFR flight plan closes automatically; the pilot does not need to make a separate cancellation call.

Note: This is an exception to the general towered-airport rule in paragraph 5.8.e.(1), Canceling IFR Flight Plan, under which an IFR flight plan otherwise closes automatically on landing rather than at the INITIAL POINT.

g. Flight Plan Status at a Non-Towered Airport. At an airport without a functioning control tower, cancellation of the IFR flight plan does not happen automatically and remains the pilot's responsibility, consistent with the general non-towered rule in paragraph 5.8.f, Canceling IFR Flight Plan, subject to the following overhead-maneuver-specific rules:

(1) Before flying the OVERHEAD MANEUVER, the pilot must initiate cancellation of the IFR flight plan with the controlling facility.

(2) The pilot must complete that cancellation only after crossing the landing threshold on the INITIAL APPROACH leg, or after landing.

Note: [VERIFY: the source states both that cancellation is "initiated" before the maneuver, (1) above, and "accomplished" after threshold crossing or landing, (2) above, without further explanation of how the two relate. One reading is that (1) is a responsibility/coordination step (for example, advising the controlling facility of intent to cancel) while (2) fixes the timing of the cancellation transmission itself; confirm this reading against a current AIM edition or the controlling facility's own guidance before briefing it as a fixed sequence.]

h. Controller-Issued Maneuver Instructions. When authorizing the OVERHEAD MANEUVER, the controlling facility may issue the following to the flight:

(1) Pattern altitude and direction of turns, using the phraseology in the Example below, unless both are standard for that airport, in which case the controlling facility may omit either or both.

(2) A request that the pilot report reaching the INITIAL POINT, using the phraseology in the Example below. The pilot's initial call is the required response.

(3) BREAK POINT information, using the phraseology in the Example below, only when the BREAK POINT is nonstandard for that airport. A request that the pilot report the break accompanies either form of the clearance; the pilot's break call is the required response.

Example: Overhead Maneuver Authorization, Nonstandard Pattern and Break Point

Speaker	Transmission
Tower	"Falcon One Two, cleared overhead maneuver, pattern altitude two thousand five hundred, left turns, break at midfield, report initial."
Pilot	"Cleared overhead maneuver, pattern altitude two thousand five hundred, left turns, break at midfield, report initial, Falcon One Two."
Pilot (reaching the INITIAL POINT)	"Falcon One Two, initial."
Tower	"Falcon One Two, report break."
Pilot (reaching the BREAK POINT)	"Falcon One Two, break."

Required response: the pilot reads back the pattern altitude, turn direction, and break point; the pilot then reports INITIAL and reports the break as requested.

Example: Overhead Maneuver Authorization, Standard Pattern

Speaker	Transmission
Pilot	"Example Tower, Cessna Four Alpha Bravo, request overhead maneuver."
Tower	"Cessna Four Alpha Bravo, cleared overhead maneuver, report initial."
Pilot	"Cleared overhead maneuver, wilco, Cessna Four Alpha Bravo."

Required response: the pilot reports INITIAL when reaching the INITIAL POINT; pattern altitude, turn direction, and BREAK POINT are standard for this airport and are not restated in the clearance.

Note: Callsigns, altitudes, and the break-point description in the examples above are generic placeholders for illustration only, not asserted real-world or network values. The pilot's exact phraseology for reporting INITIAL or the break is not prescribed by the source and is illustrative; the source establishes only that a report is requested and given, not its scripted wording.

i. Overhead Maneuver Geometry.

Table 1. Overhead Maneuver Ground Track (FIG 5-4-34)

#	Element	Description
1	INITIAL POINT	Point at which the flight begins the INITIAL APPROACH leg toward the runway.
2	INITIAL APPROACH	Leg from the INITIAL POINT to the BREAK POINT, flown over the runway.
3	BREAK POINT	Point at which the flight begins the first 180-degree turn of the maneuver.
4	Second 180-degree turn	Turn from the downwind leg rolling the flight out aligned with the runway (ROLL OUT).
5	ROLL OUT	Point at which the flight completes the second 180-degree turn and is aligned with the runway.

A distance of 3 to 5 NM (NM defined in paragraph c) appears on the published figure for this maneuver. [VERIFY: the source figure does not label which leg or segment this 3-to-5-NM distance measures; confirm against a current AIM edition or the controlling facility's local procedures before treating it as a specific leg length, such as the INITIAL POINT-to-runway distance.]

Note: Pattern altitude, turn direction, BREAK POINT location, and leg lengths are airport-specific and are set by that airport's published procedures; the callsigns, altitude, and distances used in the examples above are illustrative only and do not represent the figure's own values.

References

This chapter aggregates the following 32 source paragraphs of the real-world Aeronautical Information Manual (AIM), Chapter 5, using each source's own fetched title. Paragraph numbers on the left are this chapter's; the AIM designator and title on the right identify the source material.

This chapter	Source AIM paragraph — Title
5.1	AIM 5-1-1 — Preflight Preparation
5.2	AIM 5-1-5 — Flight Plan − VFR Flights
5.3	AIM 5-1-6 — Flight Plan - IFR Flights
5.4	AIM 5-1-7 — Flight Plans For Military/DoD Use Only
5.5	AIM 5-1-8 — Flight Plan – Defense VFR (DVFR) Flights
5.6	AIM 5-1-12 — Change in Flight Plan
5.7	AIM 5-1-14 — Closing VFR/DVFR Flight Plans
5.8	AIM 5-1-15 — Canceling IFR Flight Plan
5.9	AIM 5-2-1 — Pre-taxi Clearance Procedures
5.10	AIM 5-2-4 — Taxi Clearance
5.11	AIM 5-2-5 — Line Up and Wait (LUAW)
5.12	AIM 5-2-6 — Abbreviated IFR Departure Clearance (Cleared. . .as Filed) Procedures
5.13	AIM 5-2-8 — Departure Control
5.14	AIM 5-2-9 — Instrument Departure Procedures (DP) - Obstacle Departure Procedures (ODP), Standard Instrument Departures (SID), and Diverse Vector Areas (DVA)
5.15	AIM 5-3-1 — ARTCC Communications
5.16	AIM 5-3-2 — Position Reporting
5.17	AIM 5-3-3 — Additional Reports
5.18	AIM 5-3-4 — Airways and Route Systems
5.19	AIM 5-3-5 — Airway or Route Course Changes
5.20	AIM 5-3-8 — Holding
5.21	AIM 5-4-1 — Standard Terminal Arrival (STAR) Procedures
5.22	AIM 5-4-3 — Approach Control
5.23	AIM 5-4-4 — Advance Information on Instrument Approach
5.24	AIM 5-4-5 — Instrument Approach Procedure (IAP) Charts
5.25	AIM 5-4-6 — Approach Clearance
5.26	AIM 5-4-7 — Instrument Approach Procedures
5.27	AIM 5-4-11 — Radar Approaches
5.28	AIM 5-4-20 — Approach and Landing Minimums
5.29	AIM 5-4-21 — Missed Approach
5.30	AIM 5-4-23 — Visual Approach
5.31	AIM 5-4-25 — Contact Approach
5.32	AIM 5-4-27 — Overhead Approach Maneuver

Topics of the source AIM's Chapter 5 that were not among these 32 paragraphs, and are therefore not covered by this chapter, include: the NOTAM system (5-1-3); flights outside the U.S. and U.S. territories (5-1-11); national security and interception procedures; special instrument approach procedures (5-4-8); radar monitoring of instrument approaches (5-4-12); simultaneous approach procedures; charted visual flight procedures (5-4-24); and helicopter-specific missed-approach procedures (5-5-5). Where a paragraph above names one of these, it is a descriptive pointer only, not a citation into this chapter.

Every acronym used in this chapter that is not defined in the master Glossary at the end of this contract is spelled out at its first use within the paragraph where it appears, and any acronym used in a table is expanded in that table's own Legend, per this contract's Register and Apparatus rules.

Glossary

ADS-B / ADS-C. Automatic Dependent Surveillance-Broadcast / -Contract. See paragraphs 5.13.h, 5.15.j, and 5.16.c(4).

Approach / Approach Control. The approach control facility serving an arrival airport (paragraph 5.22.c), or, where an ARTCC sector performs this service directly, that Center sector acting in the approach-control role (paragraph 5.22.i). Paragraph 5.27 (Radar Approaches) uses "Approach Control" in this same specific sense, deliberately distinct from "Controlling facility" below, because that paragraph concerns only the terminal radar facility's own function.

ARTCC. Air Route Traffic Control Center. See "Center."

Center. The ARTCC sector working an aircraft in the en route environment, established fully in paragraph 5.15, ARTCC (Center) Communications.

Clearance Delivery. A dedicated Clearance Delivery frequency where the departure airport publishes one, or Ground, on the ground control frequency, where it does not. Established at paragraph 5.9 and used without restatement in paragraphs 5.10, 5.12, and 5.14. Paragraph 5.13 (Departure Control) extends this same convention to include Tower as a third alternative, for the narrower purpose of issuing initial-heading and RNAV SID advisories.

Controlling facility. Whichever of Tower, Approach Control, or Center is currently providing air traffic control service to the aircraft for the action described in a given paragraph. In Chapter 5's Arrival part (paragraphs 5.21–5.32), this ordinarily means Approach Control or Center, the facility vectoring, holding, or clearing the aircraft for an approach, and paragraphs there use "controlling facility" rather than "ATC" for that same referent. Paragraph 5.32 (Overhead Approach Maneuver) uses a Tower-primary variant of the same term, stated at 5.32.c, because a control tower normally authorizes and works that maneuver; at a non-towered airport the term there falls back to Approach or Center. A paragraph that means only one specific facility (for example, paragraph 5.20's holding authority, limited to Center or Approach Control, or paragraph 5.9's Clearance-Delivery-or-Ground convention above) says so explicitly rather than relying on this general definition.

DESCEND VIA. The STAR clearance form authorizing pilot-discretion descent to meet published restrictions, established at paragraph 5.21.k.

DP / ODP / SID / DVA / VCOA. Departure Procedure / Obstacle Departure Procedure / Standard Instrument Departure / Diverse Vector Area / Visual Climb Over Airport, established in paragraph 5.14, Instrument Departure Procedures.

FSS. Flight Service Station. Where staffed by a human controller on the network, the position that files, activates, briefs, and closes VFR and DVFR flight plans and relays weather. Established in paragraph 5.1.

Ground. The ground-control facility handling taxi instructions, and, at a field with no separate Clearance Delivery position, the IFR clearance as well (see "Clearance Delivery" above).

IAP / IAF / IF / FAF. Instrument Approach Procedure / Initial Approach Fix / Intermediate Fix / Final Approach Fix, established in paragraph 5.24, Instrument Approach Procedure (IAP) Charts (IAP, IAF, IF), and paragraph 5.22, Approach Control (FAF).

MDA / DA(DH). Minimum Descent Altitude / Decision Altitude (Decision Height), established in paragraph 5.24.c and paragraph 5.26.c.

Network. The multiplayer flight simulation network on which this contract's procedures apply.

NoPT / HILPT. A route or sector labeled to show no course reversal is authorized / Hold-in-Lieu-of-Procedure-Turn, established in paragraph 5.24.c.

PBN. Performance-Based Navigation, introduced in paragraph 5.3.f and applied in paragraphs 5.14.h, 5.21.m, and 5.24. See also paragraph 1.5, Performance-Based Navigation and Area Navigation (PBN/RNAV).

RF leg. Radius-to-Fix leg, a constant-radius circular path charted on some RNAV procedures, established at paragraph 5.25.l.

STAR. Standard Terminal Arrival, established in paragraph 5.21, Standard Terminal Arrival (STAR) Procedures.

TAA / MSA / MVA. Terminal Arrival Area / Minimum Safe Altitude / Minimum Vectoring Altitude, established in paragraph 5.24, subparagraphs h through j.

Tower. The local control position at a towered airport, responsible for runway assignment, line-up-and-wait and takeoff clearances, landing clearances, go-around instructions, and clearances to aircraft during landing rollout.

Working facility. Whichever facility (Departure, Approach, Center, Tower, or FSS) is currently in two-way radio contact with the pilot for the phase of flight in which a reportable event occurs. Defined at paragraph 5.17.a for the en route Additional Reports a pilot gives without being asked; distinguished from "Controlling facility" above in that it also includes Departure and FSS and is not limited to an arrival/approach-control context.

Every other acronym used in this contract is spelled out at its first use within the paragraph where it appears, and any acronym used in a table is expanded in that table's own Legend.