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REFERENCE−
14 CFR Part 135, Operating Requirements: Commuter and on Demand Operations and Rules Governing Persons on Board Such Aircraft.
14 CFR p107, Small Unmanned Aircraft Systems.
14 CFR Part 11, General Rulemaking Procedures.
F AA Order JO 7210.3, Chapter 5, Section 5, 14 CFR Part 91, UAS Operations.
2. Generally, UAS cannot comply with certain 14 CFR regulations originally written for a manned aircraft
environment and therefore require relief. UAS operators obtain relief from the requirements of these regulations
through exemptions, waivers, and deviations. The relief document lists conditions and limitations which provide
a level of safety at least equal to that provided by the rule from which relief is needed. Additionally, UAS
operators must obtain a Certificate of Waiver or Authorization (COA) from the FAA Air Traffic Organization
(ATO). Applicants for 14 CFR part 135 certification should begin the process by contacting their local FAA
Flight Standards District Office (FSDO).
NOTE−
Examples of such regulations include requirements for the provision of seat belts for aircrew and passengers, on−board
carriage of an aircraft manual, etc.
(a) Application for a 14 CFR part 135 certificate. Application for a 14 CFR part 135 air carrier certificate
for UAS operations uses the same process as that for manned 14 CFR part 135 applicants. For information on
how to apply for an air carrier certificate issued under 14 CFR part 135, see the FAA 14 CFR part 135 Air Carrier
and Operator Certification website.
NOTE−
The F AA 14 CFR part 135 Air Carrier and Operator Certification website may be reviewed at:
https://www.faa.gov/licenses_certificates/airline_certification/135_certification/ .
(b) Advisory Circular 120−49A, parts 121 and 135 Certification is available to aid an applicant in Part
135 certification.
REFERENCE−
AC 120−49, Parts 121 and 135 Certification.
(c) Exemptions and COAs. Additional information on how to petition for an exemption and obtain a
COA is available on the FAA Advanced Operations website.
NOTE−
The F AA’s Advanced Operations website may be reviewed at: https://www.faa.gov/uas/advanced_operations/ .
b. 14 CFR part 137, Agricultural Aircraft Operations:
1. Civil and public operators of UAS may conduct agricultural aircraft operations, as defined in 14 CFR
part 137.3, Definition of Terms. These operations must be conducted in accordance with an agricultural aircraft
operator certificate issued under 14 CFR part 137, and an exemption from certain federal aviation regulations
granted under 14 CFR part 11, General Rulemaking Procedures. Operators of sUAS, weighing less than 55
pounds MGOW may conduct agricultural aircraft operations under 14 CFR part 107, sUAS, and 14 CFR part
137. Operators of large UAS, weighing 55 pounds MGOW or more may conduct agricultural aircraft operations
under 14 CFR parts 91, UAS operations, and 14 CFR part 137.
REFERENCE−
14 CFR Part 137, Agricultural Aircraft Operations.
14 CFR Part 11, General Rulemaking Procedures.
14 CFR Part 107, Small Unmanned Aircraft Systems.
F AA Order JO 7210.3, Chapter 5, Section 5, 14 CFR Part 91, UAS Operations.
2. Generally, as is the case with 14 CFR part 135 standard cargo operations, UAS cannot comply with
certain 14 CFR regulations, and therefore require relief. For example, sUAS require relief from carriage of
hazardous material (§107.36), aircraft certification (§137.19(d)), carriage of agricultural aircraft operator
certificate (§137.33(a)), and, for large UAS, certain aircraft airworthiness requirements (14 CFR parts 21 and
91). UAS operators obtain relief from the requirements of these regulations through an exemption. The
exemption lists conditions and limitations which provide a level of safety at least equal to that provided by the
rule. Additionally, large UAS operators must obtain a COA from the FAA ATO.
(a) Obtaining an exemption for 14 CFR part 137 operations. For additional information on how to
petition for an exemption and obtain a COA, go to the FAA’s Advanced Operations website.
Airspace Access for UAS 11−4−5
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NOTE−
The F AA’s Advanced Operations website may be viewed at: https://www.faa.gov/uas/advanced_operations/ .
(b) Advisory Circular 137−1, Certification Process for Agricultural Aircraft Operators, provides
additional information on how to apply for an agricultural aircraft operator certificate issued under 14 CFR part
137.
REFERENCE−
AC 137−1, Certification Process for Agricultural Aircraft Operators.
c. Hazardous Materials (HAZMAT):
1. A hazardous material also known as HAZMAT, or dangerous goods is any substance or material that is
capable of posing an unreasonable risk to health, safety, and property when transported in commerce. For
example, lithium batteries, dry ice, and aerosol whipped cream are considered dangerous goods. These products
may seem harmless, but when transported by air they can be very dangerous. Vibrations, static electricity,
temperature and pressure variations can cause items to leak, generate toxic fumes, start a fire, or even explode
if these products are not packaged and handled properly. More detailed information is located on the FAA’s What
are Dangerous Goods website.
NOTE−
The F AA’s What are Dangerous Goods website may be viewed at: https://www.faa.gov/hazmat/what_is_hazmat/ .
2. The carriage/transportation of hazardous materials under 14 CFR part 107, sUAS, is strictly prohibited
at all times, and is not subject to waiver. In order to transport hazardous materials, UAS operators must follow
the 14 CFR part 135 certification regulatory path and must develop dangerous goods training programs and
manuals as part of the 14 CFR part 135 Air Carrier and Operator Certificates process, described on the FAA
website and subparagraph 11−4−5a, and 14 CFR part 135, Operating Requirements. A brief description of
applicable regulations as they apply to UAS can be found on the FAA’s UAS website.
NOTE−
The F AA’s Unmanned Aircraft System (UAS) website may be viewed at:
https://www.faa.gov/hazmat/air_carriers/operations/dr ones/.
REFERENCE−
14 CFR Part 107, Small Unmanned Aircraft Systems.
14 CFR Part 135, Operating Requirements: Commuter and on Demand Operations and Rules Governing Persons on Board Such Aircraft.
11−4−6. Airspace Restrictions To Flight
a. General. The FAA has the exclusive authority to regulate the areas of aviation safety and the efficient use
of the airspace by aircraft. Attempts by state and local governments to regulate in those areas are preempted.
Outside of those areas, the States are generally free to regulate as long as their laws do not conflict with FAA
regulations or relate to the prices, routes, or services of commercial air carriers. The NAS extends from the
ground to above 60,000 feet MSL and includes various classifications of airspace, both controlled and
uncontrolled. sUAS remote pilots and recreational flyers are generally permitted access to uncontrolled airspace
without special permission. However, this changes when access to controlled airspace is desired. All access to
controlled airspace by unmanned aircraft must be granted by ATC.
NOTE−
1. While the NAS is divided into controlled and uncontrolled airspace, users must remember that all airspace is regulated,
and certain rules apply throughout the NAS.
2. Recreational flyers are limited to no higher than 400 feet AGL in Class G airspace, without prior authorization.
3. sUAS remote pilots operating under 14 CFR part 107 are limited to no higher than 400 feet AGL unless the small UA
is (1) Flown within a 400−foot radius of a structure; and (2) Does not fly higher than 400 feet above the structure’s
immediate uppermost limit, or when a waiver has been issued to 14 CFR § 107.51(b).
b. Controlled airspace is a generic term that covers the different classification of airspace (Class A, Class B,
Class C, Class D, and Class E airspace) and defined dimensions within which air traffic control services can be
provided to Instrument Flight Rules (IFR) flights and to Visual Flight Rules (VFR) flights, in accordance with
the airspace classification.
11−4−6 Airspace Access for UAS
AIM2/20/251/22/26 AIM
c. Special Use Airspace (SUA). SUA consists of that airspace wherein flight activities must be confined
because of their nature, or wherein limitations are imposed upon aircraft operations that are not a part of those
activities, or both. These areas are generally depicted on aeronautical charts and will be indicated on the B4UFly
and LAANC applications for UAS.
d. Temporary Flight Restrictions:
1. Temporary Flight Restrictions (TFRs) are non−permanent airspace restrictions issued by the FAA via
the U.S. NOTAM System, and are created to protect persons and property in the air or on the surface from an
existing or imminent hazard associated with an incident on the surface, when the presence of low flying aircraft
would magnify, alter, spread, or compound that hazard (14 CFR Section 91.137(a)(1)). TFRs can exist to protect
aircraft from hazards, and also to protect people/objects on the ground from aircraft hazards. Examples of TFRs
include natural disaster areas especially forest fires, floods, congested flight areas, the area around spacecraft
launches and recoveries, certain stadium sporting events, and the security of national public figures.
2. UAS operators should be aware that substantial fines and penalties can be levied on UAS remote pilots
or recreational flyers violating a TFR.
e. Special Restrictions over Critical Infrastructure:
1. The FAA restricts UAS operations over certain locations, including military sites and installations, in
the interest of national security using Special Security instructions.
2. UAS operations may be permitted in these areas under limited circumstances. Operators should review
established NOTAMS for permitted operations and seek authorization prior to operating in these areas.
3. UAS remote pilots and recreational flyers must carefully consider where they are operating and
determine the legality of doing so, infractions may result in fines and legal actions.
REFERENCE−
14 CFR Section 99.7, Special Security Instructions.
f. Special Flight Rules Area (SFRA). SFRAs are airspaces of defined dimensions, above land areas or
territorial waters, within which the flight of aircraft is subject to special rules, established after the September
11, 2001, attacks. Examples include the Washington, DC, Los Angeles, and Hudson River SFRAs. All aircraft
are highly regulated within SFRAs. The inner area of some SFRAs, the Flight Restricted Zone (FRZ) is very
highly restricted and prohibits all but previously vetted aircrew and aircraft from entering. Refer to VFR
Sectional Charts or the FAA’s Restricted Airspace website for information on specific airspace limitations and
instructions for requesting entry.
NOTE−
The F AA’s Restricted Airspace website may be viewed at: https://www.faa.gov/newsroom/restricted-airspace-0.
g. State or local governments may generally enact laws applying to UAS that (1) are aimed at objectives other
than aviation safety or airspace efficiency, and (2) do not impair the reasonable use by UAS of the airspace,
including laws addressing land use or zoning; harassment of individuals or groups; privacy; voyeurism;
photography or imaging from UAS; trespass on property; the exercise of other police powers; reckless
endangerment; law enforcement; delivery of prison contraband; and taking photographs or videos. Restrictions
on how UAS are utilized (i.e., conduct), instead of where they may operate in the airspace, is more consistent
with Federal preemption principles. UAS restrictions applied to the lower UAS altitudes—that would still
permit overflight at the higher UAS altitudes—are less likely to raise preemption concerns.
h. Other Restrictions & Provisions:
1. Flight over or near natural habitat or nature preserves. See paragraph 11 −8−6, Environmental Best
Practices, for a discussion of UAS flight restrictions over or near wildlife.
2. “No Drone Zone:” To promote safe and responsible use of UAS, the FAA uses the term “No Drone Zone”
to help operators identify areas where they cannot operate UAS. The effort assists landowners (private and
public) with designating their land off−limits for UAS take−offs and landings. The outreach allows landowners
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who wish to avoid UAS interactions on their property to state this preference in advance of UAS take−offs or
landings. The “No Drone Zone” concept does not empower State or local governments to enact airspace
restrictions or to regulate the airspace. A “No Drone Zone” sign posted by a State or local government, or private
person, only applies to the ground, not the airspace. Furthermore, the sign solely designates an area where UAS
may not takeoff or land. Generally speaking, for a “No Drone Zone” in a public place to be legally enforceable,
there must exist underlying land use or zoning authority (ordinance, law, etc.). If the property in question is
privately−owned, the landowner’s right to prohibit UAS landing areas on their property is generally enforceable
through trespass law.
3. Flight over or near people and manned aircraft. In general, UAS remote pilots and recreational flyers
should avoid flying over or near people or manned aircraft operations, and in any manner that could be construed
as reckless or dangerous. See paragraph 11−8−3, Precautions: Flight Over or Near People, Manned Aircraft, and
Night Flight, for specific information on flight over or near people.
4. Correctional Institutions. Flight over some federal prisons is restricted under 14 CFR section 99.7,
Special Security Instructions. Flight near other correctional institutions may be prohibited by other federal, state
or local statutes. Subparagraph 11−4−6e, Special Restrictions over Critical Infrastructure, contains additional
information regarding restrictions over critical infrastructure.
REFERENCE−
14 CFR Section 99.7, Special Security Instructions.
11−4−7. UAS Traffic Management (UTM)
a. UTM Operations. UTM is predicated on layers of information sharing and data exchange amongst a range
of stakeholders including UAS operators, service providers, and the FAA to achieve safe operations. Operators
share their flight intent with each other and coordinate to de−conflict and safely separate trajectories. The primary
means of communication and coordination between operators, the FAA, and other stakeholders is through a
distributed information network, rather than between pilots and air traffic controllers via traditional voice
communications. The FAA makes real −time airspace constraints available to UAS operators, who are
responsible for managing their own operations safely within these constraints without receiving ATC services
from the FAA. However, the FAA does have access to applicable UTM operational information as necessary.
b. UAS operators not receiving ATC separation services are required to participate in UTM at some level
using applicable services to meet the performance requirements of their operations. See FIG 11−4−2 for UTM
in the context of Air Traffic Management operations. The number and type of services required varies based on
the type and location of the intended operation and the associated communication, navigation, surveillance
(CNS), and other operational needs.
11−4−8 Airspace Access for UAS
2/20/25 AIM
FIG 11−4−2
UTM Operations in Context of Airspace Classes
c. Stakeholders in UTM:
1. FAA, the federal authority over aircraft operations in all airspace, and the regulator and oversight
authority for civil aircraft operations in the NAS.
2. Operator, the person or entity responsible for the overall management of their operation. The operator
meets regulatory responsibilities, plans flight/operations, shares operation intent information, and safely
conducts operations using all available information.
3. Remote pilot−in−command (RPIC), the person responsible for the safe conduct of each UAS flight. An
individual may serve as both the operator and the RPIC.
4. Other stakeholders (e.g., public safety and general public), can access information and/or utilize UTM
services via the USS Network.
Airspace Access for UAS 11−4−9
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Section 5. UAS Pilot Testing, Certification and
Responsibilities
11−5−1. UAS Pilot Certification and Requirements for Part 107 and Recreational Flyers
a. General:
1. Part 107 Operations. Any person who operates a civil sUAS in the NAS, for any operation that is not
for recreational/pleasure purposes, must have a UAS pilot’s certificate (also called the “Part 107 Certificate”)
with a Small Unmanned Aircraft System Rating.
2. Recreational Flyer Operations. A person who is flying a UAS for recreational/pleasure purposes in the
NAS must have taken and passed TRUST, as required by 14 USC 44809.
b. Eligibility for Testing:
1. Part 107 operations. Applicants must be at least 16 years of age and be able to speak and understand
English. For further information on part 107 testing see the FAA’s website, Become a Drone Pilot.
2. Recreational Flyer Operations. There are no minimum age or other eligibility requirements for a
recreational UAS pilot to take TRUST.
c. Initial Testing for Certification:
1. Part 107 Operations:
(a) Current 14 CFR part 61 certificate holder (Online Training). A person who holds a part 61 manned
pilot certificate (other than a Student pilot certificate), and who has a current flight review, as per 14 CFR section
61.56, may complete Online Training that is offered by the FAA to obtain their 14 CFR part 107, in lieu of taking
the Initial Knowledge Test. However, a part 61 certificate holder may also take the sUAS Initial Aeronautical
Knowledge Test for certification.
(b) Non 14 CFR part 61 certificate holder, or 14 CFR part 61 certificate holder lacking currency (Initial
Aeronautical Knowledge Test). A person who does not hold a 14 CFR part 61 manned pilot certificate and/or
they do not have a current flight review must take the Initial Aeronautical Knowledge Test at an FAA designated
Knowledge Testing Center to obtain their sUAS Certificate.
2. Recreational Flyer Operations. Any person who flies a UAS for recreational use under 49 USC 44809
must take and pass TRUST. See the FAA website, The Recreational UAS Safety Test (TRUST).
NOTE−
A current 14 CFR part 107 sUAS certificate holder may fly recreationally under that part, but must adhere entirely to 14
CFR part 107 rules and requirements. If a part 107 sUAS certificate holder wishes to fly under 49 USC 44809, they must
take and pass TRUST.
NOTE−
The F AA’s website, The Recreational UAS Safety Test (TRUST), may be viewed at:
https://www.faa.gov/uas/recreational_flyers/knowledge_test_updates.
d. Recurrent Training (Testing) Requirements:
1. Part 107 operations:
(a) To exercise the privileges of a sUAS certificate that was issued under 14 CFR part 107, a person must
maintain currency. Therefore, the FAA requires that a person take a recurrent course within 24 months from the
month the Initial Aeronautical Knowledge Test was passed, or the Online Training was completed.
(b) Recurrent training (online training) is found at the FAA’s Become a Drone Pilot website.
NOTE−
The F AA’s Become a Drone Pilot website may be viewed at:
https://www.faa.gov/uas/commercial_operators/become_a_drone_pilot/ .
UAS Pilot Testing, Certification and Responsibilities 11−5−1
AIM 2/20/25
2. Recreational Operations. TRUST is taken on a once−and−done basis; no recurrent testing is required.
e. Pre−test Training Requirements:
1. Part 107 Operations:
(a) No documented pre− test training is required under part 107 to take the Initial Aeronautical
Knowledge Test. However, the FAA Remote Pilot Small Unmanned Aircraft Systems Study Guide is an
excellent resource.
NOTE−
To view the F AA Remote Pilot – Small Unmanned Aircraft Systems Study Guide see:
https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/media/remote_pilot_study_guide.pdf.
(b) Initial Aeronautical Knowledge Test subject areas. The testing topics for the sUAS Knowledge Test
can be found in 14 CFR section 107.73, Knowledge and Training.
REFERENCE−
14 CFR Section 107.73, Knowledge and Training.
(c) Part 107 online training. This online training may be used by those who hold a 14 CFR part 61 pilot
certificate (not including a student pilot certificate) seeking 14 CFR part 107 remote pilot certification. A person
who holds a 14 CFR part 61 pilot certificate must also show, at the time of certification, a current Flight Review
as per 14 CFR section 61.56.
2. Recreational Flyer Operations. No pre−test training is necessary to complete TRUST.
f. Endorsements and re −testing. Neither the part 107 Initial Aeronautical Knowledge Test nor the
Recreational TRUST have any requirements for flight instructor endorsements prior to testing. A person who
fails the Initial Aeronautical Knowledge Test must wait 14 calendar days before they may retake the test. TRUST
may be retaken at any time.
g. Registering to take the part 107 sUAS Initial Aeronautical Knowledge Test:
1. Before a person can take the sUAS Initial Aeronautical Knowledge Test at an FAA recognized testing
center, that person must obtain an FAA Tracking Number (FTN). To obtain an FTN a person must create an
account in the Integrated Airman Certification and Rating Application (IACRA) system. For detailed
instructions on how to obtain an FTN, see the FAA Airman Certificate Testing Service (ACTS) Contract
Briefing.
NOTE−
Any person who has any F AA Airman Certificate will already have an FTN.
NOTE−
The F AA’s Airman Certificate Testing Service (ACTS) Contract Briefing, may be viewed at:
https://www.youtube.com/watch?v=ETLsH8BruBM .
2. Once an applicant has their FTN, they will go to the testing vendor’s website and register for the test.
The FAA testing vendor is PSI Services LLC.
NOTE−
The PSI Services LLC website may be viewed at: https://candidate.psiexams.com/ .
h. Applying for a 14 CFR Part 107 sUAS Certificate. The Become a Drone Pilot website has instructions on
how to obtain the 14 CFR part 107 Pilot Certificate, following testing or online training completion.
NOTE−
The Become a Drone Pilot website may be viewed at:
https://www.faa.gov/uas/commercial_operators/become_a_drone_pilot/ .
i. Night Operations and Operations over People:
1. A person who holds a sUAS Certificate is afforded all of the privileges of the certificate. This includes
the ability to operate at night and over people without a waiver, under certain conditions. See paragraph 11−8−3,
11−5−2 UAS Pilot Testing, Certification and Responsibilities
2/20/25 AIM
Precautions: Flight Over or Near People, Vehicles, Manned Aircraft, and Night Flight, for further information
on these operations.
2. Any remote pilot who holds a 14 CFR part 107 sUAS certificate issued prior to April 6, 2021, must take
the updated recurrent training (the online training) to operate at night or over people.
11−5−2. Pilot Certification and Requirements for Public Aircraft Operations (PAOs)
a. When operating as a PAO, the operator is required to train and the agency will self −certify pilots as
competent to safely operate in the NAS.
b. For more information and best practices on pilot certification and training within the framework of a PAO,
refer to AC 00−1.1, Public Aircraft Operations—Manned and Unmanned.
REFERENCE−
AC 00−1.1, Public Aircraft Operations—Manned and Unmanned.
11−5−3. Pilot Certification for 14 CFR part 135, Part 137, and Large Civil UAS
a. Currently, FAA regulations require a commercial pilot certificate for 14 CFR part 135 Remote PICs.
b. Pilot certification for 14 CFR part 137. For civil UAS agricultural aircraft operations, the 14 CFR section
137.19(b) and (c) requirement (that the pilot hold a private or commercial pilot certificate) is exempted; only
a 14 CFR part 107 pilot certificate is required. This policy pertains to all UAS regardless of weight. However,
all civil pilots conducting agricultural aircraft operations must satisfactorily pass the knowledge and skill test
of 14 CFR section 137.19(e) and 14 CFR section 137.41(b) or (c).
c. Pilot certification for other large civil UAS. Requirements for future large civil UAS operations will be
addressed in future rulemaking.
11−5−4. Foreign Pilot Certification
a. Part 107 Operations:
1. Foreign national holding a U.S. issued 14 CFR part 61 certificate. Foreign nationals are eligible for a
sUAS certificate in the same way that a U.S. citizen is eligible.
2. Foreign national not holding a U.S. issued 14 CFR part 61 certificate. A foreign national who does not
hold a U.S.−issued 14 CFR part 61 certificate, must take and pass the Initial Aeronautical Knowledge Test to
obtain a sUAS Pilot Certificate in order to operate in the NAS.
b. Recreational Flyer Operations A foreign national is required to have passed TRUST to fly a UAS
recreationally under 49 USC 44809 in the United States.
c. Security vetting. All applicants, regardless of nationality, must pass a Transportation Security
Administration (TSA) Security Threat Analysis (STA) before the FAA will issue a temporary or permanent
Pilot’s Certificate under part 107.
d. Bi−lateral agreements. Currently, the United States does not have any bi−lateral agreements with any other
countries that would allow the issuance of a U.S. sUAS certificate that is based on a foreign UAS Pilot’s
Certificate.
UAS Pilot Testing, Certification and Responsibilities 11−5−3
2/20/25 AIM
Section 6. Advanced Air Mobility
11−6−1. General
a. Advanced Air Mobility (AAM) is a rapidly−emerging, new sector of the aerospace industry which aims
to safely and efficiently integrate highly automated aircraft into the NAS. AAM is not a single technology, but
rather a collection of new and emerging technologies being applied to the aviation transportation system,
particularly in new aircraft types. Notional AAM use−cases include Urban Air Mobility (UAM), Regional Air
Mobility (RAM), public services, large cargo delivery, and private or recreational vehicles.
b. UAM and RAM are subsets of AAM activities occurring in urban environments.
Advanced Air Mobility 11−6−1
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Section 7. UAS Operations on Airports
11−7−1. UAS Operations on Airports
a. Larger public and civil UAS operate from military, civilian and dual−use airports with set protocols and
agreements with local ATC, often operate under IFR.
b. sUAS operations on airports require coordination with the airport operator and respective air traffic control
facility, Spectrum, the FAA Regional Airport District Office, or the State Department of Aviation, where
applicable. Due to the complex nature of these operations, requests for on−airport operations within controlled
airspace must be submitted via DroneZone for coordination with the air traffic control facility. On −airport
operation requests are evaluated on a case−by−case basis due to the inherent risks associated with operating in
close proximity to areas frequented by manned aircraft.
NOTE−
The F AA’s DroneZone website may be viewed at: https://faadronezone.faa.gov/#/ .
UAS Operations on Airports 11−7−1
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Section 8. Other Information and Best Practices
11−8−1. Best Practices for UAS Operations
Responsibility of the UAS pilot. Just as is the case with a manned aircraft, the UAS remote pilot or recreational
flyer is responsible for the safe operation of their unmanned aircraft. The remote pilot or recreational flyer must
ensure that they are physically ready to fly and knowledgeable of the flight to be performed to include operational
parameters, UAS limitations, local weather, and applicable flight rules; that the UAS itself is mechanically ready.
11−8−2. UAS Operations and Air Traffic Control (ATC)
Coordination and/or communication of airspace authorizations, between UAS pilots or operators and ATC, are
handled within the airspace access processes (e.g., LAANC, DroneZone, CAPS). They are not coordinated
extemporaneously and verbally between the UAS operator and ATC. Any requirements for coordination and/or
communication between UAS operator and ATC will be contained in individual COAs, which may include
operational waivers, development of LOAs, and through other application processes which allow access to
controlled airspace. Any air traffic services provided to sUAS operations shall be based upon the type of airspace
authorization issued, along with the mitigations and limitations included in that authorization.
NOTE−
1. Small UAS operators should not contact ATC directly by radio or telephone for purposes of airspace access. Also, the
use of an aviation radio frequency by the RPIC of a sUAS may constitute a violation of Federal Communications
Commission rules. Remote pilots of larger UAS—which are usually under positive control by ATC and flying under
Instrument Flight Rules—are an exception to this guideline.
2. Small UAS operators are encouraged to monitor local CTAF radio traffic when operating on or near an airport, for
situational awareness.
11−8−3. Precautions: Flight Over or Near People, Vehicles, Manned Aircraft, and Night
Operations
a. Flight over or near people and vehicles:
1. Remote pilots and recreational flyers should carefully consider the hazards of flight operations over or
near people. 14 CFR part 107, subpart D, Operations Over Human Beings, allows certain Operations Over
People (OOP) and vehicles, based upon four different operational categories of UA weight and construction, and
the likely severity of injury to people on the ground, in the case of contact. Part 107 operators may request a
waiver to these restrictions.
2. Part 91 remote pilots may refer to restrictions and permissions, regarding flight over people, in their
respective COAs.
3. Recreational flyers should consider the safety of other persons when flying. 49 USC 44809(a)(2),
Exception for Limited Recreational Operations of Unmanned Aircraft, requires recreational flyers to operate in
accordance with the safety guidelines of an accepted CBO; these guidelines will usually include safety
precautions for flight near people.
4. For further information on the rules for flying over people or vehicles, see paragraph 11−4−6, Airspace
Restrictions to Flight.
REFERENCE−
14 CFR Part 107, Subpart D, Operations Over Human Beings.
49 USC 44809(a)(2), Exception for Limited Recreational Operations of Unmanned Aircraft.
b. Flight in the Vicinity of Manned Aircraft:
1. The pilot of any unmanned aircraft operation retains the ultimate responsibility to avoid manned aircraft
traffic. UAS operators should remember that manned aircraft may fly below 400 feet AGL; examples include
Other Information and Best Practices 11−8−1
AIM 2/20/25
helicopters, agricultural aircraft, light civil aircraft, and military aircraft. UAS pilots must ensure they have
unblocked visual access to both their UAS and the airspace around it; not seeing a manned aircraft due to blocked
line of sight does not absolve the UAS pilot from responsibility for avoidance.
2. Should public safety or emergency responder aircraft (e.g., police, fire suppression, helicopter
emergency medical services) operations be interfered with by UAS, substantial fines can be levied on the UAS
operators involved. Enforcement actions can include revocation or suspension of a pilot certificate, and up to
a $20,000 civil penalty per violation.
c. Night Operations.
1. Night operations are permitted under 14 CFR parts 91, 14 CFR part 107, and Section 44809. However,
requirements for meteorological visibility, and for the operator or visual observer (VO) to maintain VLOS with
the UAS at all times, should be considered; see subparagraph 11−5−1i.
2. 14 CFR section 107.29, Operation at Night, requirements include initial pilot training and equipment
such as an anti−collision light which is visible for at least three statute miles, with a flash rate sufficient to avoid
a collision.
3. Part 91 operators civil and PAO should refer to their specific COAs for any further instructions or
limitations on night flight.
REFERENCE−
14 CFR Section 107.29, Operation at Night.
11−8−4. Accidents and Incidents: UAS Operator Responsibilities
a. Reporting responsibility. A drone crash or malfunction, irrespective of which flight rules govern the flight,
may trigger a reporting requirement to either the FAA, the NTSB, or both. The NTSB reporting requirements
listed in 49 CFR 830.5, Immediate Notification, are separate and distinct from the FAA reporting requirements.
All UAS flyers operating in the NAS recreational, civil, and public are encouraged to read and follow NTSB
reporting requirements should they experience a crash or malfunction that meets NTSB criteria and triggers
NTSB reporting. See NTSB Reporting Requirements and subparagraph 11−8−4b. COAs issued to part 91 civil
and public operators will contain specific incident/accident reporting requirements for the operator.
1. Part 107 Operations. Part 107 operators have a reporting requirement described in 14 CFR section 107.9,
Accident Reporting. A remote pilot−in−command is required to report any sUAS crash that causes serious injury
or loss of consciousness, or property damage other than to the UAS of over $500. Property damage refers to any
property that is not part of the UA System or attached to the UAS.
2. Recreational Flyer Operations. Recreational flyers fully complying with the exception listed in 49 USC
44809 are not required to report crashes to the FAA. However, this does not alleviate the recreational flyer from
the requirement to report the crash to the NTSB if the crash meets the NTSB reporting requirements.
3. Part 91 Operations. Part 91 operators typically flown by public aircraft operators, civil aircraft operators,
or civil operators flying FAA type certificated UAS have unique reporting requirements delineated in the terms
and conditions of their certificate of waiver/authorization and must comply with those specific requirements.
b. NTSB Reporting Requirements. The NTSB defines a UAS accident as an occurrence associated with the
operations of any public or civil UAS that takes place between the time that the system is activated with the
purpose of flight and the time that the system is deactivated at the conclusion of its mission, in which any person
suffers death or serious injury, or the UAS holds an airworthiness certificate and sustains substantial damage.
In the case of a midair collision involving a UAS, any midair collision must be reported.
REFERENCE−
14 CFR Section 830.5, Immediate Notification.
14 CFR Section 107.9, Accident Reporting.
11−8−2 Other Information and Best Practices
2/20/25 AIM
11−8−5. Emergency UAS Authorizations Through Special Government Interest (SGI)
Airspace Waivers
a. Background. UAS are used by public safety agencies to respond to emergencies. The SGI process is for
any part 107 or part 91 operator that either due to time limitations, airspace restrictions or emergency situations
that requires expedited authorization by contactin g the system operations support center (SOSC) at
9−ATO R−HQ−[email protected].
b. The SGI process, depending on the nature of the operation, can be completed in a matter of minutes. This
process enables response to an emergency with UAS in an expeditious manner.
c. Public Safety organizations may apply for expedited airspace authorizations through the SGI process. The
SGI process is defined in FAA Order JO 7210.3, Facility Operation and Administration.
REFERENCE−
F AA Order JO 7210.3, Facility Operation and Administration.
d. Additional information regarding SGI authorizations can be located at the FAA’s Emergency Situations
webpage.
NOTE−
The F AA’s Emergency Situations website may be reviewed at:
https://www.faa.gov/uas/advanced_operations/emer gency_situations/.
11−8−6. Environmental Best Practices
a. Unmanned aircraft operate in a similar environment to manned aircraft. Since most UAS operations are
conducted at low altitude, hazards, risks and potential environment factors may be encountered on a more
frequent basis. In addition to the Bird Hazards, Flight over National Refuges, Parks, and Forests, the following
factors must also be considered:
1. Flight Near Protected Conservation Areas. UAS, if misused, can have devastating impacts on protected
wildlife. UAS operators may check for conservation area airspace restrictions on the B4UFLY mobile app.
2. Flight(s) Near Noise Sensitive Areas. Consider the following:
(a) UAS operations and flight paths should be planned to avoid prolonged or repetitive flight at low
altitude near noise sensitive areas.
(b) As described in FAA Order 1050.1, Environmental Impact: Policies and Procedures, an area is “noise
sensitive” if noise interferes with any normal activities associated with the area’s use.
REFERENCE−
F AA Order 1050.1, Environmental Impact: Policies and Procedures.
(c) To the extent consistent with FAA safety requirements, operators should observe best practices
developed by the National Park Service, U.S. Fish and Wildlife Service, U.S. Forest Service, and National
Oceanic and Atmospheric Administration when operating above areas administered by those agencies. The
National Park Service provides additional guidance at their Unmanned Aircraft Systems website.
NOTE−
The National Park Service, Unmanned Aircraft Systems website may be viewed at:
https://www.nps.gov/subjects/sound/uas.htm .
b. Some bird species have shown the potential to attack UAS that approach their nesting and hunting areas
too closely. The type of birds that are most likely to attack sUAS are raptors such as hawks, eagles, and falcons.
However, gulls, geese, and crows have also been known to attack UAS. Aggressive bird attacks may damage
UAS propellers or other critical equipment, and may result in sudden loss of power or engine failure. Remote
pilots and recreational flyers should consider reviewing engine−out procedures, especially when operating near
high bird concentrations.
Other Information and Best Practices 11−8−3
AIM 2/20/253/15/077110.65R CHG 2AIM 8/7/25
11−8−7. Resources for UAS Operators
a. FAA.GOV/UAS. The FAA UAS website, www.faa.gov/uas, is the central point for information about FAA
UAS rules, regulations, and safety best practices.
b. FAA DroneZone. The FAA DroneZone is the Agency’s portal for registering drones, requesting part 107
airspace authorizations and waivers, registering as a CBO, requesting fixed flying sites, and other tasks.
c. Local FAA offices (Flight Standards District Offices/FSDOs). FSDOs can be the best in−person source for
UAS information. A list of FSDOs in the United States is at
https://www.faa.gov/about/office_org/field_offices/fsdo/all_fsdos/.
d. Aeronautical Information. The FAA provides aeronautical information to NAS users, including UAS
pilots, through a variety of methods, including publications like this manual, other publications, Advisory
Circulars (ACs), charts, website and mobile applications, etc.
Check https://www.faa.gov/air_traffic/flight_info/aeronav/safety_alerts/ for these items.
e. The UAS Support Center. For general question or comment about UAS or drones, the FAA’s Support
Center is available at 844−FLY−MY−UA or [email protected].
f. Clubs and Associations. Local UAS recreational clubs, CBO organizations, and business associations are
excellent resources for information and updates on flying in the local region.
g. LAANC. LAANC is the Low Altitude Authorization and Notification Capability, a collaboration between
FAA and industry. It automates the application and approval process for airspace authorizations. Using
applications developed by an FAA −approved UAS service supplier (USS) you can apply for an airspace
authorization at over 600 airports. Download the free LAANC app at
https://www.faa.gov/uas/programs_partnerships/data_exchange/.
h. B4UFLY . The B4UFLY mobile application is a partnership between the FAA and Kittyhawk. The app
helps recreational flyers know whether it is sa fe to fly their drone, as well as increases their situational awareness.
Download the free B4UFLY app at https://www.faa.gov/uas/recreational_fliers/where_can_i_fly/b4ufly/.
i. Weather Sources. Aviation weather services (such as https://www.aviationweather.gov/) are generally
targeted towards manned aviation, the FAA is currently working on UAS−specific weather applications.
j. NOTAMs. The Notice to Airmen (NOTAM) system, like aviation weather sources, remains primarily
predicated on manned aviation needs. However, the system provides continual updates on all aviation activity
(to include UAS flight activities which have been input to the FAA), as well as airport status. The NOTAM
system will be of greatest use to larger UAS activities, UAS en route operations in controlled airspace, and those
flying to or from airports. NOTAMs, temporary flight restrictions (TFRs), and aircraft safety alerts can be
accessed at https://www.faa.gov/pilots/safety/notams_tfr/.
11−8−4 Other Information and Best Practices
2/20/25 AIM
Appendix 1. Bird/Other Wildlife Strike Report
Bird/Other Wildlife Strike Report Appendix 1−1
AIM 2/20/25
Appendix 1−2 Bird/Other Wildlife Strike Report
FOLD AND TAPE HERE
2/20/25 AIM
Appendix 2. Volcanic Activity Reporting Form (VAR)
VOLCANIC ACTIVITY REPORT
Air−reports are critically important in assessing the hazards which volcanic ash cloud presents to aircraft operations.
OPERATOR: A/C IDENTIFICATION: (as indicated on flight plan)
PILOT-IN-COMMAND:
DEP FROM: DATE: TIME; UTC: ARR AT: DATE: TIME; UTC:
ADDRESSEE AIREP SPECIAL
Items 1–8 are to be reported immediately to the ATS unit that you are in contact with.
1) AIRCRAFT IDENTIFICATION 2) POSITION
3) TIME 4) FLIGHT LEVEL OR ALTITUDE
5) VOLCANIC ACTIVITY OBSERVED AT
(position or bearing, estimated level of ash cloud and distance from aircraft)
6) AIR TEMPERATURE 7) SPOT WIND
Other
8) SUPPLEMENTARY INFORMATION
SO2 detected Yes No
Ash encountered Yes No (Brief description of activity especially vertical and lateral extent of ash cloud and,
where possible, horizontal movement, rate of growth, etc.)
After landing complete items 9–16 then fax form to: (Fax number to be provided by the meteorological authority based on local arrangements between the
meteorological authority and the operator concerned.)
9) DENSITY OF ASH CLOUD (a) Wispy (b) Moderate dense (c) Very dense
10) COLOUR OF ASH CLOUD (a) White (b) Light grey (c) Dark grey
(d) Black (e) Other
11) ERUPTION (a) Continuous (b) Intermittent (c) Not visible
12) POSITION OF ACTIVITY (a) Summit (b) Side (c) Single
(d) Multiple (e) Not observed
13) OTHER OBSERVED (a) Lightning (b) Glow (c) Large rocks
FEATURES OF ERUPTION (d) Ash fallout (e) Mushroom cloud (f) All
14) EFFECT ON AIRCRAFT (a) Communication (b) Navigation systems (c) Engines
(d) Pitot static (e) Windscreen (f) Windows
15) OTHER EFFECTS (a) Turbulence (b) St. Elmo’s Fire (c) Other fumes
16) OTHER INFORMATION
(Any information considered useful.)
Date: 07/19/2010
V olcanic Activity Reporting Form (V AR) Appendix 2−1
AIM2/20/257/9/26 AIM
Appendix 3. Abbreviations/Acronyms
As used in this manual, the following abbreviations/acronyms have the meanings indicated.
Abbreviation/
Acronym
Meaning
A A W U ..... Alaskan Aviation Weather Unit
A A S ....... Airport Advisory Service
A A M ...... Advanced Air Mobility
ABRR ...... Airborne Reroutes
A C ........ Advisory Circular
ACAR ..... Aircraft Communications Addressing and
Reporting System
A C L ....... Aircraft List
ADCUS .... Advise Customs
ADDS ...... Aviation Digital Data Service
A D F ....... Automatic Direction Finder
ADIZ ...... Air Defense Identification Zone
ADS−B ..... Automatic Dependent
Surveillance−Broadcast
A F B ....... Air Force Base
AFCS ...... Automatic Flight Control System
AFIS ....... Automatic Flight Information Service
A F M ....... Aircraft Flight Manual
A G L ....... Above Ground Level
AHRS ...... Attitude Heading Reference System
A I M ....... Aeronautical Information Manual
AIRMET . . . Airmen’s Meteorological Information
A I S ........ Aeronautical Information Services
A L D ....... Available Landing Distance
ALDARS . . . Automated Lightning Detection and
Reporting System
A L S ....... Approach Light Systems
AMSL ..... Above Mean Sea Level
A N P ....... Actual Navigation Performance
AOCC ..... Airline Operations Control Center
A P ........ Autopilot System
A P V ....... Approach with Vertical Guidance
A R ........ Authorization Required
ARENA .... Areas Noted for Attention
ARFF IC .... Aircraft Rescue and Fire Fighting Incident
Commander
ARINC ..... Aeronautical Radio Incorporated
A R O ....... Airport Reservations Office
ARSA ...... Airport Radar Service Area
ARSR ...... Air Route Surveillance Radar
A R T C C ..... Air Route Traffic Control Center
A S ........ Altimeter Setting
ASDE−X ... Airport Surface Detection Equipment −
Model X
Abbreviation/
Acronym
Meaning
ASOS ...... Automated Surface Observing System
A S R ....... Airport Surveillance Radar
ASRS ...... Aviation Safety Reporting System
ASSC Airport Surface Surveillance Capability
A T C ....... Air Traffic Control
ATCRBS .... Air Traffic Control Radar Beacon System
ATCSCC .... Air Traffic Control System Command
Center
A T C T ...... Airport Traffic Control Tower
A T D ....... Along−Track Distance
A T I S ....... Automatic Terminal Information Service
A T O ....... Air Traffic Organization
A T T ....... Attitude Retention System
A W C ....... Aviation Weather Center
A W O S ..... Automated Weather Observing System
A W T T ..... Aviation Weather Technology Transfer
A W W ...... Severe Weather Forecast Alert
BAASS ..... Bigelow Aerospace Advanced Space
Studies
B B S ....... Bulletin Board System
B C ........ Back Course
BECMG .... Becoming group
BVLOS .... Beyond Visual Line of Sight
C / A ........ Coarse Acquisition
C A A ....... Confirm Assigned Altitude
C A T ....... Clear Air Turbulence
C B O ....... Community−Based Organization
C C F ....... Combined Control Facility
C D ........ Controller Display
C D I ........ Course Deviation Indicator
C D R ....... Coded Departure Route
C F A ....... Controlled Firing Area
CFIT ....... Controlled Flight into Terrain
C F R ....... Code of Federal Regulations
C O A ....... Certificate of Waiver or Authorization
CPDLC ..... Controller Pilot Data Link
Communications
C T A F ...... Common Traffic Advisory Frequency
CVFP ...... Charted Visual Flight Procedure
CVRS ...... Computerized V oice Reservation System
C W A ....... Center Weather Advisory
CWSU ..... Center Weather Service Unit
D A ........ Decision Altitude
Abbreviations/Acronyms Appendix 3−1
AIM 2/20/253/15/077110.65R CHG 2AIM 1/22/26
Abbreviation/
Acronym
Meaning
D C A ....... Ronald Reagan Washington National
Airport
D C P ....... Data Collection Package
D E R ....... Departure End of Runway
D H ........ Decision Height
D M E ....... Distance Measuring Equipment
DME/N ..... Standard DME
DME/P ..... Precision DME
D o D ....... Department of Defense
D P ........ Instrument Departure Procedure
D P U ....... Data Processor Unit
D R T ....... Diversion Recovery Tool
D R V S M .... Domestic Reduced Vertical Separation
Minimum
D V A ....... Diverse Vector Area
DVFR ...... Defense Visual Flight Rules
DVRSN .... Diversion
EDCT ...... Expect Departure Clearance Time
E F A S ...... En Route Flight Advisory Service
E F V ....... Enhanced Flight Visibility
EFVS ...... Enhanced Flight Vision System
E L T ........ Emergency Locator Transmitter
EMAS ..... Engineered Materials Arresting System
E P E ....... Estimate of Position Error
E S V ....... Expanded Service V olume
E T A ....... Estimated Time of Arrival
E T D ....... Estimated Time of Departure
E T E ....... Estimated Time En Route
EWINS ..... Enhanced Weather Information System
E W R ....... Newark International Airport
F A ......... Area Forecast
F A A ....... Federal Aviation Administration
F A F........ Final Approach Fix
F A W P ...... Final Approach Waypoint
F B ......... Fly−by
F C C ....... Federal Communications Commission
F D ........ Flight Director System
F D B ....... Full Data Block
F D C ....... Flight Data Center
F D E ....... Fault Detection and Exclusion
F I R ........ Flight Information Region
F I S ........ Flight Information Service
FISDL ..... Flight Information Services Data Link
FLIP ....... Flight Information Publication
F M S ....... Flight Management System
F O ........ Fly−over
F P A ........ Flight Path Angle
Abbreviation/
Acronym
Meaning
F P V ....... Flight Path Vector
FPNM ...... Feet Per Nautical Mile
FRIA ...... FAA−Recognized Identification Area
FSDO ...... Flight Standards District Office
F S S ........ Flight Service Station
GBAS ...... Ground Based Augmentation System
G E O ....... Geostationary Satellite
G L S ....... GBAS Landing System
GNSS ...... Global Navigation Satellite System
GNSSP ..... Global Navigation Satellite System Panel
G P S ....... Global Positioning System
G R I ........ Group Repetition Interval
G S D ....... Geographical Situation Display
G U S ....... Ground Uplink Station
H A T ....... Height Above Touchdown
HAZMAT . . . Hazardous Material
H D T A ...... High Density Traffic Airports
HEMS ..... Helicopter Emergency Medical Services
HIRL ...... High Intensity Runway Lights
H R R ....... Helicopter Rapid Refueling Procedures
H U D ....... Head−Up Display
H z ......... Hertz
I A F ........ Initial Approach Fix
I A P ........ Instrument Approach Procedure
I A S ........ Indicated Air Speed
I A W P ...... Initial Approach Waypoint
I C ......... Initial Contact
ICAO ...... International Civil Aviation Organization
I F ......... Intermediate Fix
I F R ........ Instrument Flight Rules
I L S ........ Instrument Landing System
ILS/PRM . . . Instrument Landing System/Precision
Runway Monitor
I M ......... Inner Marker
I M C ....... Instrument Meteorological Conditions
InFO ....... Information For Operators
I N S ........ Inertial Navigation System
I O C ........ Initial Operational Capability
I R ......... IFR Military Training Route
I R U ........ Inertial Reference Unit
ITWS ...... Integrated Terminal Weather System
J F K ........ John F. Kennedy International Airport
k H z ........ Kilohertz
L A A ....... Local Airport Advisory
LAANC .... Low Altitude Authorization and
Notification Capability
Appendix 3−2 Abbreviations/Acronyms
AIM2/20/251/22/26 AIM
Abbreviation/
Acronym
Meaning
LAAS ...... Local Area Augmentation System
LAHSO .... Land and Hold Short Operations
L A W R S .... Limited Aviation Weather Reporting
Station
L D A ....... Localizer Type Directional Aid
LDA/PRM . . Localizer Type Directional Aid/Precision
Runway Monitor
L G A ....... LaGuardia Airport
LIRL ....... Low Intensity Runway Lights
L L W A S ..... Low Level Wind Shear Alert System
LLWAS NE . Low Level Wind Shear Alert System
Network Expansion
LLWAS−RS . Low Level Wind Shear Alert System
Relocation/Sustainment
L N A V ...... Lateral Navigation
L O C ....... Localizer
L O P ....... Line−of−position
LORAN .... Long Range Navigation System
L P ......... Localizer Performance
L P V ....... Localizer Performance with Vertical
Guidance
L U A W ..... Line Up and Wait
L Z ......... Landing Zone
MAHWP . . . Missed Approach Holding Waypoint
M A P ....... Missed Approach Point
M A W P ..... Missed Approach Waypoint
M D A ...... Minimum Descent Altitude
M E A ....... Minimum En Route Altitude
MEARTS . . . Micro En Route Automated Radar
Tracking System
M E T A R .... Aviation Routine Weather Report
MGOW .... Maximum Gross Operating Weight
M H z ....... Megahertz
MIRL ...... Medium Intensity Runway Lights
M M ....... Middle Marker
M O A ...... Military Operations Area
MOCA ..... Minimum Obstruction Clearance Altitude
M R A ...... Minimum Reception Altitude
M R B ....... Magnetic Reference Bearing
M S A ....... Minimum Safe Altitude
M S A W ..... Minimum Safe Altitude Warning
M S L ....... Mean Sea Level
M T I ....... Moving Target Indicator
M T O S ...... Mountain Obscuration
M T R ....... Military Training Route
M V A ....... Minimum Vectoring Altitude
M W A ...... Mountain Wave Activity
M W O ...... Meteorological Watch Office
Abbreviation/
Acronym
Meaning
N A S ....... National Airspace System
NASA ...... National Aeronautics and Space
Administration
N A V A I D .... Navigational Aid
NA VCEN . . . Coast Guard Navigation Center
NCWF ..... National Convective Weather Forecast
N D B ....... Nondirectional Radio Beacon
NEXRAD . . . Next Generation Weather Radar
N G A ....... National Geospatial−Intelligence Agency
N M ........ Nautical Mile
NMAC ..... Near Midair Collision
NOAA ..... National Oceanic and Atmospheric
Administration
N O P A C .... North Pacific
NoPT ...... No Procedure Turn Required
N P A ....... Nonprecision Approach
N R S ....... Navigation Reference System
N S A ....... National Security Area
N S W ....... No Significant Weather
NTSB ...... National Transportation Safety Board
N T Z ....... No Transgression Zone
N W S ....... National Weather Service
O A T ....... Outside Air Temperature
O B S ....... Omni−bearing Selector
O D P ....... Obstacle Departure Procedure
O I S ........ Operational Information System
O I S ........ Obstacle Identification Surface
O M ........ Outer Marker
O O P ....... Operations Over People
O R D ....... Chicago O’Hare International Airport
P/CG ....... Pilot/Controller Glossary
P A ......... Precision Approach
P A O ....... Public Aircraft Operation
P A P I ....... Precision Approach Path Indicator
P A R ....... Precision Approach Radar
P A R ....... Preferred Arrival Route
P C ......... Personal Computer
P D C ....... Pre−departure Clearance
P F D ....... Personal Flotation Device
P I C ........ Pilot−in−Command
PinS ....... Point−in−Space
PIREP ...... Pilot Weather Report
P O B ....... Persons on Board
POFZ ...... Precision Obstacle Free Zone
P O I ........ Principal Operations Inspector
P P S ........ Precise Positioning Service
Abbreviations/Acronyms Appendix 3−3
AIM 2/20/253/15/077110.65R CHG 2AIM 1/22/26
Abbreviation/
Acronym
Meaning
P R M ....... Precision Runway Monitor
P T ......... Procedure Turn
QICP ...... Qualified Internet Communications
Provider
R A ........ Resolution Advisory
R A A ....... Remote Advisory Airport
RAIM ...... Receiver Autonomous Integrity Monitoring
RAIS ...... Remote Airport Information Service
RBDT ...... Ribbon Display Terminals
R C ........ Radio−Controlled
RCAG ..... Remote Center Air/Ground
R C C ....... Rescue Coordination Center
RCLS ...... Runway Centerline Lighting System
R C O ....... Remote Communications Outlet
R I D ........ Remote Identification
RPIC ....... Remote Pilot−in−Command
T A F ....... Aerodrome Forecast
R D ........ Rotor Diameter
REIL ....... Runway End Identifier Lights
R E L ....... Runway Entrance Lights
R F M ....... Rotorcraft Flight Manual
RLIM ...... Runway Light Intensity Monitor
R M I ....... Radio Magnetic Indicator
R N A V ...... Area Navigation
R N P ....... Required Navigation Performance
R O C ....... Required Obstacle Clearance
R P A T ...... RNP Parallel Approach Runway
Transitions
R V R ....... Runway Visual Range
R V S M ...... Reduced Vertical Separation Minimum
R W S L ...... Runway Status Light
S A A ....... Sense and Avoid
SAFO ...... Safety Alerts For Operators
S A M ....... System Area Monitor
S A R ....... Search and Rescue
S A S ....... Stability Augmentation System
S A T R ...... Special Air Traffic Rules
SBAS ...... Satellite−based Augmentation System
S D F ....... Simplified Directional Facility
S F L ........ Sequenced Flashing Lights
S F R ....... Special Flight Rules
SFRA ...... Special Flight Rules Area
S G I ........ Special Government Interest
SIAP ....... Standard Instrument Approach Procedure
S I D ........ Standard Instrument Departure
SIGMET .... Significant Meteorological Information
S M ........ Statute Mile
Abbreviation/
Acronym
Meaning
SMGCS .... Surface Movement Guidance Control
System
S N R ....... Signal−to−noise Ratio
SOIA ...... Simultaneous Offset Instrument
Approaches
S O P ....... Standard Operating Procedure
S P C ....... Storm Prediction Center
S P S ........ Standard Positioning Service
S T A R ...... Standard Terminal Arrival
S T A R S ..... Standard Terminal Automation
Replacement System
STMP ...... Special Traffic Management Program
sUAS ...... Small UAS
T A ......... Traffic Advisory
T A A ....... Terminal Arrival Area
T A C ....... Terminal Area Chart
TACAN .... Tactical Air Navigation
T A S ....... True Air Speed
TCAS ...... Traffic Alert and Collision Avoidance
System
T C H ....... Threshold Crossing Height
T D ........ Time Difference
TDLS ...... Tower Data Link System
TDWR ..... Terminal Doppler Weather Radar
T D Z ....... Touchdown Zone
TDZE ...... Touchdown Zone Elevation
TDZL ...... Touchdown Zone Lights
T E C ....... Tower En Route Control
T H L ....... Takeoff Hold Lights
T I S ........ Traffic Information Service
TIS−B ...... Traffic Information Service−Broadcast
T L S ....... Transponder Landing System
T O C ....... Transfer of Communications
T P P ........ Terminal Procedures Publications
TRSA ...... Terminal Radar Service Area
TRUST ..... The Recreational UAS Safety Test
T S O ....... Technical Standard Order
TWIB ...... Terminal Weather Information for Pilots
System
U.S. ....... United States
U A ........ Unmanned Aircraft
U A M ...... Urban Air Mobility
U A S ....... Unmanned Aircraft System
UASFM .... UAS Facility Map
U A V ....... Unmanned Aerial Vehicle
U F O ....... Unidentified Flying Object
U H F ....... Ultrahigh Frequency
Appendix 3−4 Abbreviations/Acronyms
AIM2/20/251/22/26 AIM
USCG ...... United States Coast Guard
Abbreviation/
Acronym
Meaning
U T C ....... Coordinated Universal Time
U T M ....... UAS Traffic Management
U W S ....... Urgent Weather SIGMET
U W S ....... Urgent Weather SIGMET
V A R ....... V olcanic Activity Reporting
V A S I ....... Visual Approach Slope Indicator
VCOA ..... Visual Climb Over the Airport
V D A ....... Vertical Descent Angle
V D P ....... Visual Descent Point
V F R ....... Visual Flight Rules
VGSI ...... Visual Glide Slope Indicator
V H F ....... Very High Frequency
V I P ........ Video Integrator Processor
VLOS ...... Visual Line of Sight
V M C ...... Visual Meteorological Conditions
VMINI ...... Instrument flight minimum speed, utilized
in complying with minimum limit speed
requirements for instrument flight
V N A V ...... Vertical Navigation
VNE ....... Never exceed speed
VNEI ....... Instrument flight never exceed speed,
utilized instead of VNE for compliance with
maximum limit speed requirements for
instrument flight
V O ........ Visual Observer
V O R ....... Very High Frequency Omni−directional
Range
VORTAC . . . VHF Omni−directional Range/Tactical Air
Navigation
V O T ....... VOR Test Facility
V R ........ VFR Military Training Route
Abbreviation/
Acronym
Meaning
VREF ....... The reference landing approach speed,
usually about 1.3 times Vso plus 50 percent
of the wind gust speed in excess of the
mean wind speed.
VSO ........ The stalling speed or the minimum steady
flight speed in the landing configuration at
maximum weight.
V T F ....... Vector to Final
V V ........ Vertical Visibility
V V I ....... Vertical Velocity Indicator
VY ........ Speed for best rate of climb
VYI ........ Instrument climb speed, utilized instead of
VY for compliance with the climb
requirements for instrument flight
W A ........ AIRMET
W A A S ..... Wide Area Augmentation System
W F O ....... Weather Forecast Office
WGS−8 4 .... World Geodetic System of 1984
W M O ...... World Meteorological Organization
WMS . . Wide−Area Master Station
WMSC ..... Weather Message Switching Center
WMSCR .... Weather Message Switching Center
Replacement
W P ........ Waypoint
W R A ...... Weather Reconnaissance Area
W R S ....... Wide−Area Ground Reference Station
W S ........ SIGMET
WSO ...... Weather Service Office
W S P ....... Weather Systems Processor
W S T ....... Convective Significant Meteorological
Information
W W ....... Severe Weather Watch Bulletin
Abbreviations/Acronyms Appendix 3−5
2/20/25 AIM
Appendix 4. FAA Form 7233−4 − International Flight
Plan
a. The FAA will accept a flight plan in international format for IFR, VFR, SFRA, and DVFR flights. File the
flight plan electronically via a Flight Service Station (FSS), FAA contracted flight plan filing service, or other
commercial flight plan filing service. Depending on the filing service chosen, the method of entering data may
be different but the information required is generally the same.
b. The international flight plan format is mandatory for:
1. Any flight plan filed through a FSS or FAA contracted flight plan filing service; with the exception of
Department of Defense flight plans and civilian stereo route flight plans, which can still be filed using the format
prescribed in FAA Form 7233−1.
NOTE−
DoD Form DD−175 and F AA Form 7233−1 are considered to follow the same format.
2. Any flight that will depart U.S. domestic airspace. For DoD flight plan purposes, offshore Warning Areas
may use FAA Form 7233−1 or military equivalent.
3. Any flight requesting routing that requires Performance Based Navigation.
4. Any flight requesting services that require filing of capabilities only supported in the international flight
plan format.
c. Flight Plan Contents
1. A flight plan will include information shown below:
(a) Flight Specific Information (TBL 4−1)
(b) Aircraft Specific Information (TBL 4−19)
(c) Flight Routing Information (TBL 4−20)
(d) Flight Specific Supplementary Information (Item 19)
2. The tables indicate where the information is located in the international flight plan format, the information
required for U.S. domestic flights, and the location of equivalent information in the domestic flight plan format.
3. International flights, including those that temporarily leave domestic U.S. airspace and return, require all
applicable information in the international flight plan. Additional information can be found in ICAO Doc. 4444
(Procedures for Air Navigation Services, Air Traffic Management), and ICAO Doc. 7030 (Regional
Supplemental Procedures) as well as the Aeronautical Information Publications (AIPs), Aeronautical
Information Circulars (AICs), and NOTAMs of applicable other countries.
FAA Form 7233−4 − International Flight Plan Appendix 4−1
AIM 2/20/25
TBL 4−1
Flight Specific Information
Item International Flight
Plan (FAA Form 7233−4) Domestic U.S. Requirements
Equivalent Item on
Domestic Flight Plan
(FAA Form 7233−1)
Aircraft Identification Item 7 Required Item 2
Flight Rules Item 8 Required Item 1
Type of Flight Item 8 No need to file for domestic U.S. flight N/A
Equipment and Capabilities
Item 10
Item 18 PBN/; NAV/; COM/; DA T/;
SUR/
Required Item 3
Date of Flight Item 18 DOF/ Include when date of flight is not today N/A
Reasons for Special Handling Item 18 STS/; RMK/ Include when special category is applicable Item 11
Remarks Item 18 RMK/ Include when necessary Item 11
Operator Item 18 OPR/ No need to file for domestic U.S. flight N/A
Flight Plan Originator Item 18 ORGN/ No need to file for domestic U.S. flight N/A
d. Instructions for Flight−Specific Information Items
1. Aircraft Identification (Item 7) Aircraft Identification is always required. Aircraft identification must not
exceed seven alphanumeric characters and be either:
(a) The ICAO designator for the aircraft operating agency, followed by the flight identification (for
example, KLM511, NGA213, JTR25). When in radiotelephony the call sign to be used by the aircraft will consist
of the ICAO telephony designator for the operating agency followed by the flight identification (for example,
KLM511, NIGERIA213, JESTER25);
(b) The nationality or common mark and registration of the aircraft (for example, EIAKO, 4XBCD,
N2567GA), when:
(1) In radiotelephony, the call sign to be used by the aircraft will consist of this identification alone
(for example, CGAJS) or preceded by the ICAO telephony designator for the aircraft operating agency (for
example, BLIZZARD CGAJS); or
(2) The aircraft is not equipped with radio.
NOTE−
1. Standards for nationality, common and registration marks to be used are contained in Annex 7, Chapter 2.
2. Provisions for using radiotelephony call signs are contained in Annex 10, V olume II, Chapter 5. ICAO designators and
telephony designators for aircraft operating agencies are contained in Doc 8585—Designators for Aircraft Operating
Agencies, Aeronautical Authorities and Services.
NOTE−
Some countries’ aircraft identifications begin with a number , which cannot be processed by U.S. ATC automation. The
FAA will add a leading letter temporarily to gain automation acceptance for aircraft identifications that begin with a
numeral. For flight −processing systems (e.g., ERAM or STARS) which will not accept a call sign that begins with a
number, if the call sign is 6 characters or less, add a Q at the beginning of the call sign. If the call sign is 7 charac-
ters, delete the first character and replace it with a Q. Put the original call sign in the remarks section of the flight
plan.
EXAMPLE−
9HRA becomes Q9HRA
5744233 becomes Q744233
2. Flight Rules (Item 8a)
(a) Flight rules are always required.
Appendix 4−2 FAA Form 7233−4 − International Flight Plan
2/20/25 AIM
(b) Flight rules must indicate IFR (I) or VFR (V).
(c) For composite flight plans, submit separate flight plans for the IFR and VFR portions of the flight.
Specify in Item 15 the point or points where change of flight rules is planned. The IFR plan will be routed to
ATC, and the VFR plan will be routed to a Flight Service for Search and Rescue services.
NOTE−
The pilot is responsible for opening and closing the VFR flight plan. ATC does not have knowledge of a VFR flight
plan’s status.
3. Type of Flight (Item 8b)
(a) The type of flight is optional for flights remaining wholly within U.S. domestic airspace.
(b) Indicate the type of flight as follows:
G − General Aviation
S − Scheduled Air Service
N − Non−Scheduled Air Transport Operation
M − Military
X − other than any of the defined categories above
4. Equipment and Capabilities (Item 10, Item 18 NA V/, COM/, DAT/, SUR/)
(a) Equipment and capabilities that can be filed in a flight plan include:
Navigation capabilities in Item 10a, Item 18 PBN/, and Item 18 NA V/
V oice communication capabilities in Item 10a and Item 18 COM/
Data communication capabilities in Item 10a and Item 18 DAT/
Approach capabilities in Item 10a and Item 18 NA V/
Surveillance capabilities in Item 10b and Item 18 SUR/
(b) Codes allowed in Item 10a are shown in Table 4−2. Codes allowed in Item 10b are shown in TBL 4−3.
Codes recognized in Item 18 NA V/, COM/, DAT/, and SUR/ are shown in TBL 4−4. Note that other service
providers may define additional allowable (and required) codes for use in Item 18 NA V/, COM/, DAT/, or SUR/.
Codes to designate PBN capability are described in TBL 4−5.
Radio communication, navigation and approach aid equipment and capabilities
ENTER one letter as follows:
N if no COM/NA V/approach aid equipment for the route to be flown is carried, or the equipment is
unserviceable,
OR
S if standard COM/NA V/approach aid equipment for the route to be flown is carried and serviceable
(see Note 1),
AND/OR
ENTER one or more of the following letters from TBL 4 −2 to indicate the serviceable COM/NA V/ approach
aid equipment and capabilities available.
FAA Form 7233−4 − International Flight Plan Appendix 4−3
AIM 2/20/25
TBL 4−2
Item 10a Navigation, Communication, and Approach Aid Capabilities
A GBAS Landing System J7 CPDLC FANS 1/A SATCOM
B LPV (APV with SBAS) (Iridium)
C LORAN C K MLS
D DME L ILS
E1 FMC WPR ACARS M1 ATC SATVOICE (INMARSAT)
E2 D−FIS ACARS M2 Reserved
E3 PDC ACARS M3 ATC RTF (Iridium)
F ADF O VOR
G GNSS (See Note 2) P1 CPDLC RCP 400 (See Note 7)
H HF RTF P2 CPDLC RCP 240 (See Note 7)
I Inertial Navigation P3 SATVOICE RCP 400 (See Note 7)
J1 CPDLC ATN VDL Mode 2 (See Note 3) P4−P9 Reserved for RCP
J2 CPDLC FANS 1/A HFDL R PBN Approved (See Note 4)
J3 CPDLC FANS 1/A VDL Mode A T TACAN
J4 CPDLC FANS 1/A Mode 2 U UHF RTF
J5 CPDLC FANS 1/A SATCOM V VHF RTF
(INMARSA T) W RVSM Approved
J6 Reserved X MNPS Approved /North Atlantic (NAT)
High Level Airspace (HLA) approved
Y VHF with 8.33 kHz Channel Spacing
Capability
Z Other equipment carried or other
capabilities (See Note 5)
Any alphanumeric characters not indicated above are reserved.
NOTE−
1. If the letter “S” is used, standard equipment is considered to be VHF RTF , VOR, and ILS, unless another combina-
tion is prescribed by the appropriate ATS authority.
2. If the letter “G” is used, the types of external GNSS augmentation, if any, are specified in Item 18 following the indicator
NAV/ and separated by a space.
EXAMPLE−
NAV/SBAS
3. See RTCA/EUROCAE Interoperability Requirements Standard for ATN Baseline 1 (ATN B1 INTEROP Standard – DO
–280B/ED−110B) for data link services air traffic control clearance and information/air traffic control communications
management/air traffic control microphone check.
4. If the letter “R” is used, the performance−based navigation levels that can be met are specific in Item 18 following the
indicator PBN/. Guidance material on the application of performance −based navigation to a specific route segment,
route, or area is contained in the Performance −based Navigation (PBN) Manual (Doc 9613)
5. If the letter “Z” is used, specify in Item 18 the other equipment carried or other capabilities, preceded by COM/, NAV/,
and/or DAT, as appropriate.
6. Information on navigation capability is provided to ATC for clearance and routing purposes.
7. Guidance on the application of performance −based communication, which prescribes RCP to an air traffic service in
a specific area, is contained in the Performance −based Communication and Surveillance (PBCS) Manual (Doc 9869).
Appendix 4−4 FAA Form 7233−4 − International Flight Plan
2/20/25 AIM
TBL 4−3
Item 10b Surveillance Capabilities
ENTER “N” if no surveillance equipment for the route to be flown is carried, or the equipment is unserviceable,
or
ENTER One or more of the following descriptors, to a maximum of 20 characters, to describe the serviceable surveillance
equipment and/or capabilities on board.
ENTER no more than one transponder code (Modes A, C, or S)
SSR Modes A and C:
A Transponder Mode A (4 digits – 4096 codes)
C Transponder Mode A (4 digits – 4096 codes) and Mode C
SSR Mode S:
E Transponder Mode S, including aircraft identification, pressure−altitude, and extended squitter
(ADS−B) capability
H Transponder Mode S, including aircraft identification, pressure−altitude, and enhanced surveillance
capability
I Transponder Mode S, including aircraft identification, but no pressure−altitude capability
L Transponder Mode S, including aircraft identification, pressure−altitude, extended squitter (ADS−B),
and enhanced surveillance capability
P Transponder Mode S, including pressure−altitude, but no aircraft identification capability
S Transponder Mode S, including both pressure−altitude and aircraft identification capability
X Transponder Mode S, with neither aircraft identification nor pressure−altitude
NOTE−
Enhanced surveillance capability is the ability of the aircraft to down−link aircraft derived data via Mode S transponder.
ADS−B:
B1 ADS− B with dedicated 1090 MHz ADS−B “out” capability
B2 ADS −B with dedicated 1090 MHz ADS−B “out” and “in” capability
U1 ADS −B with “out” capability using UAT
U2 ADS− B with “out” and “in” capability using UAT
V1 ADS− B with “out” capability using VDL Mode 4
V2 ADS −B with “out” and “in” capability using VDL Mode 4
NOTE−
File no more than one code for each type of capability, e.g., file B1 or B2 and not both
ADS−C:
D1 ADS −C with FANS 1/A capabilities
G1 ADS− C with ATN capabilities
Alphanumeric characters not included above are reserved.
EXAMPLE−
ADE3RV/HB2U2V2G1
NOTE−
1. The RSP specification(s), if applicable, will be listed in Item 18 following the indicator SUR/, using the characters
“RSP” followed by the specifications value. Currently RSP180 and RSP400 are in use.
2. List additional surveillance equipment or capabilities in Item 18 following the indicator SUR/.
FAA Form 7233−4 − International Flight Plan Appendix 4−5
AIM 2/20/25
TBL 4−4
Item 18 NA V/, COM/, DAT/, and SUR/ capabilities used by FAA
Item Purpose Entry Explanation
NA V/ entries
used by FAA
Radius to Fix (RF)
capability
Z1 RNP−capable flight is authorized for Radius to Fix operations.
Fixed Radius Transitions
(FRT)
Z2 RNP−capable flight is authorized for Fixed Radius Transi-
tions.
Time of Arrival Control
(TOAC)
Z5 RNP−capable flight is authorized for Time of Arrival Control.
Advanced RNP (A−RNP) P1 Flight is authorized for A−RNP operations.
Helicopter RNP 0.3 R1 Flight is authorized for RNP 0.3 operations (pertains to
helicopters only).
RNP 2 Continental M1 Flight is authorized for RNP 2 continental operations.
RNP 2 Oceanic/Remote M2 Flight is authorized for RNP 2 oceanic/remote operations.
COM/ entries
used by FAA N/A N/A The FAA currently does not use any entries in COM/.
DAT/ entries
used by FAA
Capability and preference
for delivery of pre−depar-
ture clearance
Priority number
followed by:
FANS
FANSP
PDC
VOICE
Entries are combined with a priority number, for example;
1FANS2PDC means a preference for departure clearance
delivered via FANS 1/A; with capability to also receive the
clearance via ACARS PDC.
FANS = FANS 1/A DCL
FANSP = FANS 1/A+ DCL
PDC = ACARS PDC
VOICE = PDC via voice (no automated delivery)
SUR/ entries
used by FAA
Req. Surveillance Perfor-
mance
RSP180 Aircraft is authorized for Required Surveillance Performance
RSP180
RSP400 Aircraft is authorized for Required Surveillance Performance
RSP400
ADS−B A2 Aircraft has 1090 MHz Extended Squitter ADS−B compliant
with RTCA DO−260B (complies with FAA requirements)
A2 Aircraft has 978 MHz UAT ADS−B compliant with RTCA
DO−282B (complies with FAA requirements)
NOTE−
1. Other entries in NAV/, COM/, DAT/, and SUR/ are permitted for international flights when instructed by other service
providers. Direction on use of these capabilities by the F AA is detailed in the following sections.
2. In NAV/, descriptors for advanced capabilities (Z1, P1, R1, M1, and M2) should be entered as a single character string
with no intervening spaces, and separated from any other entries in NAV/ by a space.
EXAMPLE−
NAV/Z1P1M2 SBAS
Appendix 4−6 FAA Form 7233−4 − International Flight Plan
2/20/25 AIM
TBL 4−5
Item 18. PBN/ Specifications
(Include as many of the applicable descriptors, up to a maximum of 8 entries (not more than 16 characters).
PBN/ RNA V SPECIFICATIONS
A1 RNA V 10 (RNP 10)
B1 RNA V 5 all permitted sensors
B2 RNA V 5 GNSS
B3 RNA V 5 DME/DME
B4 RNA V 5 VOR/DME
B5 RNA V 5 INS or IRS
B6 RNA V 5 LORAN C
C1 RNA V 2 all permitted sensors
C2 RNA V 2 GNSS
C3 RNA V 2 DME/DME
C4 RNA V 2 DME/DME/IRU
D1 RNA V 1 all permitted sensors
D2 RNA V 1 GNSS
D3 RNA V 1 DME/DME
D4 RNA V 1 DME/DME/IRU
PBN/ RNP SPECIFICATIONS
L1 RNP 4
O1 Basic RNP 1 all permitted sensors
O2 Basic RNP 1 GNSS
O3 Basic RNP 1 DME/DME
O4 Basic RNP 1 DME/DME/IRU
S1 RNP APCH
S2 RNP APCH with BARO−VNA V
T1 RNP AR APCH with RF (special
authorization required)
T2 RNP AR APCH without RF (special
authorization required)
NOTE−
1. PBN Codes B1−B6 indicates RNAV 5 capability. The F AA considers these B codes to be synonymous and qualifying
for point−to−point routing but not for assignment to the PBN routes shown in the table.
2. Combinations of alphanumeric characters not included above are reserved.
3. The PBN/ specifications are allowed per ICAO Doc. 4444. The F AA makes use of a subset of these codes as described
in the section on filing navigation capability.
(c) The following sections detail what capabilities need to be provided to obtain services from the FAA for:
IFR flights (general).
Assignment of Performance−Based Navigation (PBN) routes.
Automated Departure clearance (via Datacom DCL or PDC).
Reduced Vertical Separation Minima (if requesting FL 290 or above).
Reduced Separation in Oceanic Airspace.
(d) Capabilities such as voice communications, required communications performance, approach aids, and
ADS−C, are not required in a flight plan that remains entirely within domestic airspace.
FAA Form 7233−4 − International Flight Plan Appendix 4−7
AIM 2/20/25
(e) Flights that leave domestic United States airspace may be required to include additional capabilities,
per requirements for the FIRs being overflown. Consult the appropriate State Aeronautical Information
Publications for requirements.
(f) Include the capability only if:
The requisite equipment is installed and operational;
The crew is trained as required; and
Any required Operations Specification, Letter of Authorization, or other approvals are in hand.
NOTE−
Do not include a capability solely based on the installed equipment if an operational approval is required. For exam-
ple, all U.S. civil operators require either Operations Specification, Management Specification, or Letter of
Authorization B036, as applicable, in order to include NAV/M2 (RNP 2 (oceanic/remote)), PBN/A1 (RNAV 10 (RNP
10)), or PBN/L1 (RNP 4) in Item 18.
5. Filing equipment and capability in an IFR Flight Plan. This section details the minimum requirements to
identify capabilities in an IFR flight plan for flights in the domestic United States. Other requirements to file
a capability are associated with obtaining specific services as described in subsequent sections. The basic
capabilities that must be addressed include Navigation, Transponder, Voice, and ADS−B Out as described below.
A designator for “Standard” capability is also allowed to cover a suite of commonly carried voice, navigation,
and approach equipment with one code.
(a) Standard Capability and No Capability (Item 10a)
Use “S” if VHF radio, VOR, and ILS equipment for the route to be flown are carried and service-
able. Use of the ’S’ removes the need to list these three capabilities separately.
Use “N” if no communications, navigation, or approach aid equipment for the route to be flown
are carried or the equipment is unserviceable.
When there is no transponder, ADS−B, or ADS−C capability then file only the letter ’N’ in Item
10b.
(b) Navigation Capabilities (Item 10a, Item 18 NA V/)
Indicate radio navigation capability by filing one or more of the codes in TBL 4−6.
Indicate Area Navigation (RNA V) capability by filing one or more of the codes in TBL 4−7.
TBL 4−6
Radio Navigation Capabilities
Capability Item 10a Item 18 NA V/
VOR O
DME D
TACAN T
TBL 4−7
Area Navigation Capabilities
Capability Item 10a Item 18 NA V/
GNSS G SBAS (if WAAS equipped)
GBAS (if LAAS equipped)
INS I
DME / DME DR
VOR / DME DOR
NOTE−
1. SBAS – Space−Based Augmentation System
GBAS − Ground−Based Augmentation System
Appendix 4−8 FAA Form 7233−4 − International Flight Plan
2/20/25 AIM
2. No PBN/ code needs to be filed to indicate the ability to fly point −to−point routes using GNSS or INS.
3. Filing one of these four area navigation capabilities as shown does not indicate performance based navigation sufficient
for flying Q−Routes, T−Routes, or RNAV SIDs or STARs. T o qualify for these routes, see the section on Performance Based
Navigation Routes.
(c) Transponder Capabilities (Item 10b)
For domestic flights, it is not necessary to indicate Mode S capability. It is acceptable to simply
file one of the following codes in TBL 4−8.
TBL 4−8
Mode C
Capability Item 10b
Transponder with no Mode C A
Transponder with Mode C C
International flights must file in accordance with relevant AIPs and regional supplements. Include
one of the Mode S codes in TBL 4−9, if appropriate.
NOTE−
File only one transponder code.
TBL 4−9
Mode S
Capability Aircraft
Altitude
Encoding
Item
10b
Mode S Transponder No No X
Mode S Transponder No Yes P
Mode S Transponder Yes No I
Mode S Transponder Yes Yes S
Mode S Transponder with Extended Squitter Yes Yes E
Enhanced Mode S Transponder Yes Yes H
Enhanced Mode S Transponder with Extended Squitter Yes Yes L
(d) ADS−B Capabilities (Item 10b, Item 18 SUR/ and Item 18 CODE/)
Indicate ADS−B capability as shown in TBL 4−10. The accompanying entry in Item 18 indicates
that the equipment is compliant with 14 CFR §91.227. Some ADS−B equipment used in other countries is
based on an earlier standard and does not meet U.S. requirements.
Do not file an ADS−B code for “in” capability only. There is currently no way to indicate that an
aircraft has “in” capability but no “out” capability.
For aircraft with ADS−B “out” on one frequency and “in” on another, include only the ADS−B
“out” code. For example, B1 or U1, (See TBL 4−10).
TBL 4−10
ADS−B Capabilities
Capability Item
10b
Item 18
SUR/
1090 ES Out Capability B1 A2
1090 ES Out and In Capability B2 A2
UAT Out Capability U1 A2
UAT Out and In Capability U2 A2
FAA Form 7233−4 − International Flight Plan Appendix 4−9
AIM 2/20/25
(e) Voice Communication Capabilities (Item 10a)
The FAA does not require indication of voice communication capabilities in a flight plan for domestic flights,
but it is permissible. For flights outside the domestic United States, all relevant capabilities must be indicated
as follows (See TBL 4−11):
TBL 4−11
Voice Communication Capabilities
Capability Item 10a
VHF Radio V
UHF Radio U
HF Radio H
VHF Radio (8.33 kHZ Spacing) Y
ATC SATVOICE (INMARSAT) M1
ATC SATVOICE (Iridium) M3
(f) Approach Aid Capabilities (Item 10a).
The FAA does not require filing of approach aid capability in order to request a specific type of approach,
however any of the codes indicated in TBL 4−12 in 10a are permissible.
International flights may be required to indicate approach capability, based on instructions from
relevant service providers.
TBL 4−12
Approach Aid Capabilities
Capability Item 10a
ILS L
MLS K
LPV Approach (APV with SBAS) (WAAS) B
GBAS Landing System (LAAS) A
6. Performance−Based Navigation Routes (Item 10a, Item 18 PBN/, Item 18 NA V/)− When planning to fly
routes that require PBN capability, file the appropriate capability as shown in TBL 4−13.
Appendix 4−10 FAA Form 7233−4 − International Flight Plan
AIM2/20/258/7/25 AIM
TBL 4−13
Filing for Performance Based Navigation (PBN) Routes
Type of Routing Capability Required Item 10a
Item 18 PBN/
See NOTE 2
Item 18 NA V/
See NOTE 3
Notes
RNA V SID or STAR
(See NOTE 1) RNA V 1
GR D2 If GNSS
DIR D4 If DME/DME/IRU
RNP SID or STAR
(See NOTE 2)
RNP 1
GNSS GR O2 If GNSS only
RNP 1
GNSS DGIR O1 If GNSS primary and
DME/DME/IRU backup
RNP SID or STAR with RF
required
(See NOTE 2)
RNP 1
GNSS GRZ O2 Z1 If GNSS only
RNP 1
GNSS DGIRZ O1 Z1 If GNSS primary and
DME/DME/IRU backup
Domestic Q −Route (see
separate requirements for
Gulf of America
Q−Routes)
RNA V 2
GR C2 If GNSS
DIR C4 If DME/DME/IRU
T−Route RNA V 2 GR C2 GNSS is required for
T−Routes
RNA V (GPS) Approach RNP Approach, GPS GR S1
Domestic arrivals do not
need to file PBN approach
capabilities to request the
approach.
RNA V (GPS) Approach RNP Approach, GPS
Baro−VNA V GR S2
RNA V (GPS) Approach
with RF required
RNP Approach, GPS
RF Capability GRZ S2 Z1
RNP AR Approach with
RF
RNP (Special Autho-
rization Required) RF
Leg Capability
GR T1
RNP AR Approach with-
out RF
RNP (Special Autho-
rization Required) GR T2
NOTE−
1. If the flight is requesting an RNAV SID only (no RNAV STAR) or RNAV STAR only (no RNAV SID) then consult guidance
on the F AA website at
https://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/air_traffic_services/flight_plan_filing.
2. PBN descriptor D1 includes the capabilities of D2, D3, and D4. PBN descriptor B1 includes the capabilities of B2,
B3, B4, and B5. PBN descriptor C1 includes the capabilities of C2, C3, and C4.
3. In NAV/, descriptors for advanced capabilities (Z1, P1, R1, M1, and M2) should be entered as a single character string
with no intervening spaces, and separated from any other entries in NAV/ by a space.
EXAMPLE−
NAV/Z1P1M2 SBAS
7. Automated Departure Clearance Delivery (DCL or PDC). When planning to use automated pre−departure
clearance delivery capability, file as indicated below.
(a) PDC provides pre−departure clearances from the FAA to the operator’s designated flight operations
center, which then delivers the clearance to the pilot by various means. Use of PDC does not require any special
flight plan entry.
(b) DCL provides pre−departure clearances from the FAA directly to the cockpit/FMS via Controller Pilot
Datalink Communications (CPDLC). Use of DCL requires flight plan entries as follows:
FAA Form 7233−4 − International Flight Plan Appendix 4−11
AIM 2/20/253/15/077110.65R CHG 2AIM 8/7/25
Include CPDLC codes in Item 10a only if the flight is capable of en route/oceanic CPDLC, the
codes are not required for DCL.
Include Z in Item 10a to indicate there is information provided in Item 18 DAT/.
Include the clearance delivery methods of which the flight is capable, and order of preference in
Item 18 DAT/. (See AIM 5−2−2)
○ VOICE − deliver clearance via V oice
○ PDC − deliver clearance via PDC
○ FANS − deliver clearance via FANS 1/A
○ FANSP − deliver clearance via FANS 1/A+
EXAMPLE−
DAT/1FANS2PDC
DAT/1FANSP2VOICE
8. Operating in Reduced Vertical Separation Minima (RVSM) Airspace (Item 10a). When planning to fly in
RVSM airspace (FL 290 up to and including FL 410) then file as indicated below.
(a) If capable and approved for RVSM operations, per AIM 4 −6−1, Applicability and RVSM Mandate
(Date/Time and Area), file a W in Item 10a. Include the aircraft registration mark in Item 18 REG/, which is used
to post−operationally monitor the safety of RVSM operations.
Do not file a “W” in Item 10a if the aircraft is capable of RVSM operations, but is not approved to
operate in RVSM airspace.
If RVSM capability is lost after the flight plan is filed, request that ATC remove the ’W’ from Item
10a.
(b) When requesting to operate non−RVSM in RVSM airspace, using one of the exceptions identified in
AIM 4−6−10, do not include a “W” in Item 10a. Include STS/NONRVSM in Item 18. STS/NONRVSM is used
only as part of a request to operate non−RVSM in RVSM airspace.
9. Eligibility for Reduced Oceanic Separation. Indicate eligibility for the listed reduced separation minima
as indicated in the tables below. Full Operational Requirements for these services are found in the U.S.
Aeronautical Information Publication (AIP) ENR 7, Oceanic Operations, available at
http://www.faa.gov/air_traffic/publications/atpubs/aip_html/index.html.
TBL 4−14
Filing for Gulf of America CTA
Dimension
of Separa-
tion
Separation
Minima
ADS−C Surveillance
Requirements
Comm. Re-
quirement
PBN Re-
quirement
Flight Plan Entries
ADS−C in
Item 10b
CPDLC in
Item 10a
PBN in Item 18
PBN/
(also File ’R’ in
Item 10a)
PBN in
Item 18
NA V/
V oice comm−
HF or VHF as
Lateral 50 NM
N/A
(ADS−C not
required)
required to
maintain con-
tact over the
RNP10
or
RNP4
N/A N/A A1 or L1 N/A
entire route to
be flown.
NOTE−
If not RNAV10/RNP10 capable and planning to operate in the Gulf of America CTA, then put the notation NON-
RNP10 in Item 18 RMK/, preferably first.
Appendix 4−12 FAA Form 7233−4 − International Flight Plan
2/20/25 AIM
TBL 4−15
Filing for 50 NM Lateral Separation in Anchorage Arctic FIR
Dimension
of Separa-
tion
Separa-
tion Mini-
ma
ADS−C Surveillance
Requirements
Comm. Re-
quirement
PBN Require-
ment
Flight Plan Entries
ADS−C in
Item 10b
CPDLC in
Item 10a
PBN in Item 18
PBN/
(also File ’R’ in
Item 10a)
PBN in
Item 18
NA V/
N/A
None be -
yond normal
RNP10
Lateral 50 NM (ADS−C not requirements or N/A N/A A1 or L1 N/A
required) for the RNP4
airspace
TBL 4−16
Filing for 20 NM, 30 NM and 50 NM Longitudinal; and 23 NM and 30 NM Lateral Oceanic Separation in
Anchorage, Oakland, and New Y ork Oceanic CTAs
Dimension of
Separation
Separation
Minima
ADS−C Surveillance
Requirements
Comm. Re-
quirement
PBN Require-
ment
Flight Plan Entries
ADS−C in
Item 10b
CPDLC in
Item 10a
PBN in Item
18 PBN/
(also File ’R’
in Item 10a)
PBN in
Item 18
NA V/
Longitudinal 50 NM
Position report at
least every 27 min-
utes (at least every 32
minutes if both air-
craft are approved
for RNP −4 opera -
tions)
CPDLC RNP10 D1
J5 and/or
J6 and/or
A1 N/A
Longitudinal 30 NM
ADS−C position re-
port at least every 10
minutes
CPDLC RNP4 D1
J5 and/or
J6 and/or
L1 N/A
Longitudinal 20 NM
ADS−C position
report at least every
192 seconds
CPDLC RNP4 D1
J5 and/or
J7 L1 N/A
FAA Form 7233−4 − International Flight Plan Appendix 4−13
AIM 2/20/253/15/077110.65R CHG 2AIM 7/9/26
Lateral 30 NM
ADS−C−based later-
al deviation event
contract with 5NM
lateral deviation
from planned routing
set as threshold for
triggering ADS re -
port of lateral devia-
tion event
CPDLC RNP4 D1
J5 and/or
J7 L1 N/A
Lateral 23 NM
ADS−C−based later-
al deviation event
contract with 5NM
lateral deviation
from planned routing
set as threshold for
triggering ADS re -
port of lateral devia-
tion event
CPDLC RNP4 D1
J5 and/or
J7 L1 N/A
TBL 4−17
Filing for Reduced Oceanic Separation when RSP/RCP Required on March 29, 2018
Dimension of
Separation
Separation
Minima
RSP Re-
quirement
RCP Re-
quirement
PBN Require-
ment
Flight Plan Entries
RSP in Item
18 SUR/
RCP in
Item
10a
CDPLC
in
Item10a
PBN in Item 18
PBN/
(also File ’R’ in
Item 10a)
PBN in
Item 18
NA V/
Lateral 55.5 km
30 NM
180 240
RNP 2 or
RNP 4
RSP180 P2 J5,
and/or
J6,
and/or
Perfor-
mance−
based
Longitudinal
5 Minutes 180 240 RNA V 10
(RNP 10)
RNP 4, or
RNP 2
oceanic/
remote
RSP180 P2 J5,
and/or
J6,
and/or
A1 or L1 M2
Perfor-
mance−
based
Longitudinal
55.5 km
30 NM
180 240
RNP 4 or
RNP 2
oceanic/
remote
RSP180 P2 J5,
and/or
J6,
and/or
L1 M2
Perfor-
mance−
based
Longitudinal
93 km
50 NM
180 240
RNA V 10
(RNP 10) or
RNP 4
RSP180 P2 J5,
and/or
J6,
and/or
A1 or L1
Appendix 4−14 FAA Form 7233−4 − International Flight Plan
AIM2/20/257/9/26 AIM
NOTE−
1. Filing of RNP 2 alone is not supported in F AA controlled airspace; PBN/L1 (for RNP 4) or PBN/A1 (for RNP 10) must
be filed to obtain the indicated separation.
2. Use of “RNP2” in NAV/ signifies continental RNP 2 (and means the same as M1). Continental RNP 2 is not adequate
for reduced oceanic separation. Descriptor M2 indicates RNP 2 global/oceanic RNP 2 capability.
10. Date of Flight (Item 18 DOF/)
Flights planned more than 23 hours after the time the flight plan is filed, must include the date of flight in DOF/
expressed in a six−digit format YYMMDD, where YY equals the year (Y), MM equals the month, and DD equals
the day.
NOTE−
FAA ATC systems will not accept flight plans more than 23 hours prior to their proposed departure time. F AA Flight
Service and commercial flight planning services generally accept flight plans earlier and forward to ATC at an appro-
priate time, typically 2 to 4 hours before the flight.
EXAMPLE−
DOF/171130
11. Reasons for Special Handling (Item 18 STS/)
(a) Indicate the applicable Special Handling in Item 18 STS/ as shown in TBL 4−18.
NOTE−
Priority for a flight is not automatically granted based on filing one of these codes but is based on documented proce -
dures. In some cases, additional information may also be required in remarks; follow all such instructions as well.
TBL 4−18
Special Handling
Special Handling Item 18 STS/
Flight operating in accordance with an altitude reservation ALTRV
Flight approved for exemption from ATFM measures by the appropriate ATS authority ATFMX
Fire Fighting FFR
Flight check for calibration of NA V AIDS FLTCK
Flight carrying hazardous material(s) HAZMA T
Flight with Head of State status HEAD
Medical flight declared by medical authorities HOSP
Flight operating on a humanitarian mission HUM
Flight for which a military entity assumes responsibility for separation of military aircraft MARSA
Life critical medical emergency evacuation MEDEV AC
Non−RVSM capable flight intending to operate in RVSM airspace NONRVSM
Flight engaged in a search and rescue mission SAR
Flight engaged in military, customs, or police services STATE
(b) Any other requests for special handling must be made in Item 18 RMK/.
(c) Include plain−language remarks when required by ATC or deemed necessary. Do not use special
characters, for example; / * − = +.
EXAMPLE−
RMK/NRP
RMK/DVRSN
12. Remarks
FAA Form 7233−4 − International Flight Plan Appendix 4−15
AIM 2/20/253/15/077110.65R CHG 2AIM 7/9/26
Include when necessary.
13. Operator (Item 18 OPR/)
When the operator is not obvious from the aircraft identification, the operator may be indicated.
EXAMPLE−
OPR/NETJETS
14. Flight Plan Originator (Item 18 ORGN/)
(a) VFR flight plans originating outside of FAA FSS or FAA contracted flight plan filing services must enter
the 8−letter AFTN address of the service where the flight plan was originally filed. Alternately, enter the name
of the service where the FPL was originally filed. This information is critical to locating the FPL originator in
the event additional information is needed.
(b) For IFR flight plans, the original filers AFTN address may be indicated, which is helpful in cases where
a flight plan has been forwarded.
EXAMPLE−
ORGN/Acme Flight Plans
ORGN/KDENXLDS
TBL 4−19
Aircraft Specific Information
Item
International Flight Plan
(FAA Form 7233−4) Domestic U.S. Requirements
Equivalent Item on
Domestic Flight Plan
(FAA Form 7233−1)
Number of Aircraft Item 9 Included when more than one a/c in flight Item 3
Type of Aircraft Item 9 Required Item 3
Wake Turbulence Category Item 9 Required N/A
Aircraft Registration Item 18 REG/
Include when planning to operate in RVSM
airspace N/A
Mode S Address Item 18 CODE/ Not required within U.S. controlled airspace N/A
SELCAL Codes Item 18 SEL/ Include when SELCAL equipped N/A
Performance Category Item 18 PER/ Not required for domestic flights N/A
e. Instructions for Aircraft−Specific Information.
1. Number of Aircraft (Item 9) when there is more than one aircraft in the flight; indicate the number of
aircraft up to 99.
2. Type of Aircraft (Item 9)
(a) Provide the appropriate 2−4 character aircraft type designator listed in FAA Order JO 7360.1, Aircraft
Type Designators. FAA Order JO 7360.1 may be located at: Orders & Notices (faa.gov), then enter 7360.1 in
the Search box.
(b) When there is no designator for the aircraft type use ’ZZZZ’, and provide a description in Item 18 TYP/.
3. Wake Turbulence Category (Item 9)
A Wake Turbulence Category is required for all aircraft types. Provide the appropriate wake turbulence category
for the aircraft type as listed in FAA Order 7360.1. The categories include:
(a) J − SUPER, aircraft types specified as such in FAA Order JO 7360.1, Aircraft Type Designators.
(b) H − HEAVY, to indicate an aircraft type with a maximum certificated take−off mass of 300,000 lbs. or
more, with the exception of aircraft types listed in FAA Order JO 7360.1 in the SUPER (J) category.
Appendix 4−16 FAA Form 7233−4 − International Flight Plan
AIM2/20/257/9/26 AIM
(c) M − MEDIUM, to indicate an aircraft type with a maximum certificated take −off mass of less than
300,000 lbs. but more than 15,500 lbs.
(d) L − LIGHT, to indicate an aircraft type with a maximum certificated take−off mass of 15,500 lbs. or
less.
4. Aircraft Registration (Item 18 REG/)
The aircraft registration must be provided here if different from the Item 7 entry. The registration mark must not
include any spaces or hyphens. Additionally, the actual aircraft registration must also be included if Item 7 would
have contained a leading numeric and was modified to be prefixed with the appropriate alphabetic character for
U.S. ATC acceptance.
EXAMPLE−
U.S. aircraft with registration N789AK
REG/N789AK
Belgian aircraft with registration OO−FA H
REG/OOFAH
5. Mode S Address (Item 18 CODE/)
There is no U.S. requirement to file the aircraft Mode S Code in Item 18.
6. SELCAL code (Item 18 SEL/)
(a) Flights with HF radio and Selective Calling capability should include their 4−letter SELCAL code. Per
the U.S. AIP, GEN 3.4, Paragraph 9, Selective Calling System (SELCAL) Facilities Available.
(b) The SELCAL is a communication system that permits the selective calling of individual aircraft over
radio−telephone channels from the ground station to properly equipped aircraft, to eliminate the need for the
flight crew to constantly monitor the frequency in use.
EXAMPLE−
SEL/CLEF
7. Performance Category (Item 18 PER/)
Include the appropriate single−letter Aircraft Approach Category as defined in the Pilot/Controller Glossary.
EXAMPLE−
PER/A
TBL 4−20
Flight Routing Information
Item
International Flight Plan
(FAA Form 7233−4) Domestic U.S. Requirements
Equivalent Item on
Domestic Flight Plan
(FAA Form 7233−1)
Departure Airport Item 13 Required Item 2
Departure Time Item 13 Required Item 1
Cruise Speed Item 15 Required N/A
Requested Altitude Item 15 Required Item 3
Route Item 15 Required N/A
Delay En Route Item 15, Item 18 DLE/ Required N/A
Destination Airport Item 16 Required Item 11
Total Estimated Elapsed Time Item 16 Required Item
FAA Form 7233−4 − International Flight Plan Appendix 4−17
AIM 2/20/253/15/077110.65R CHG 2AIM 7/9/26
Alternate Airport
Item 16
Item 18 AL TN/ (Destination Alternate).
RALT/ (En route Alternate); TALT/
(Take−off Alternate)
If necessary
No need to file for domestic U.S. flight
N/A
Estimated Elapsed Times Item 18 EET/
Include when filing flight plan with center
other than departure center N/A
f. Instructions for Flight Routing Items
1. Departure Airport (Item 13, Item 18 DEP/)
(a) Enter the departure airport. The airport should be identified using the four −letter location identifier
accessible through FAA Order JO 7350.9, Location Identifiers, or from ICAO Document 7910. FSS and FAA
contracted flight plan filing services will allow up to 11 characters in the departure field. This will permit entry
of non− ICAO identifier airports, and other fixes such as an intersection, fix/radial/distance, and
latitude/longitude coordinates. Other electronic filing services may require a different format.
NOTE−
While user interfaces for flight plan filing are not specified, all flight plan filing services must adhere to the appropri -
ate Interface Control Document upon transmission of the flight plan to the control facility.
(b) When the intended departure airport (Item 13) is outside of domestic U.S. airspace, or if using the paper
version of FAA Form 7233−4, or DoD equivalent, if the chosen flight plan filing service does not allow
non−ICAO airport identifiers in Item 13 or Item 16, use the following ICAO procedure. Enter four Z’s (ZZZZ)
in Item 13 and include the non−ICAO airport location identifier, fix, or waypoint location in Item 18 DEP/. A
text description following the location identifier is permissible in Item 18 DEP/.
NOTE−
Use of non−ICAO identifiers in Item 13 and Item 16 is only permissible when flight destination is within U.S.
airspace. If the destination is outside of the U.S., then both Item 13 and Item 16 must contain either a valid ICAO air-
port identifier or ZZZZ. Use of non−ICAO departure point is not permitted in Item 13 if destination in Item 16 is
outside of U.S.
EXAMPLE−
DEP/MD21
DEP/W29 BAY BRIDGE AIRPORT
DEP/EMI211017
DEP/3925N07722W
2. Departure Time (Item 13)
Indicate the expected departure time using 4 digits, 2 digits for hours and 2 digits for minutes. Time is to be
entered as Coordinated Universal Time (UTC).
3. Requested Cruising Speed (Item 15)
(a) Include the requested cruising speed as True Airspeed in knots using an N followed by four digits.
EXAMPLE−
(b) Indicate the requested cruising speed in Mach using an M followed by three digits.
EXAMPLE−
4. Requested Cruising Altitude or Flight Level (Item 15)
(a) Indicate a Requested Flight Level using the letter F followed by 3 digits.
EXAMPLE−
(b) Indicate a Requested Altitude in hundreds of feet using the letter A followed by 3 digits.
Appendix 4−18 FAA Form 7233−4 − International Flight Plan
AIM2/20/257/9/26 AIM
EXAMPLE−
5. Route (Item 15)
Provide the requested route of flight using a combination of published routes, latitude/longitude, and/or fixes
in the following formats.
(a) Consecutive fixes, lat/long points, NA V AIDs, and waypoints should be separated by the characters
“DCT”, meaning direct.
EXAMPLE−
FLACK DCT IRW DCT IRW12503
4020N07205W DCT MONEY
(b) A published route should be preceded by a fix that is published on the route, indicating where the route
will be joined. The published route should be followed by a fix that is published as part of the route, indicating
where the route will be exited.
EXAMPLE−
DALL3 EIC V18 MEI LGC4
(c) It is acceptable to specify intended speed and altitude changes along the route by appending an oblique
stroke followed by the next speed and altitude. However, note that FAA ATC systems will neither process this
information nor display it to ATC personnel. Pilots are expected to maintain the last assigned altitude and request
revised altitude clearances from ATC.
EXAMPLE−
DCT APN J177 LEXOR/N0467F380 J177 TAM/N0464F390 J177
6. Delay En Route (Item 15, Item 18 DLE/)
(a) ICAO defines Item 18 DLE/ to provide information about a delay en route. International flights with
a delay outside U.S. domestic airspace should indicate the place and duration of the delay in Item 18 DLE/. The
delay is expressed by a fix identifier followed by the duration in hours (H) and minutes (M), HHMM.
EXAMPLE−
DLE/EMI0140
(b) U.S. ATC systems will accept but not process information in DLE/. Therefore, for flights in the lower
48 states, it is preferable to include the delay as part of the route (Item 15). Delay in this format is specified by
an oblique stroke (/) followed by the letter D, followed by 2 digits for hours (H) of delay, followed by a plus sign
(+), followed by 2 digits for minutes (M) of delay: /DHH+MM.
EXAMPLE−
DCT EMI/D01+40 DCT MAPEL/D00+30 V143 DELRO DCT
7. Destination Airport (Item 16, Item 18 DEST/)
(a) Enter the destination airport. The airport should be identified using the four −letter location identifier
accessible through FAA Order JO 7350.9, Location Identifiers, or from ICAO Document 7910. FSS and FAA
contracted flight plan filing services will allow up to 11 characters in the destination field. This will permit entry
of non− ICAO identifier airports, and other fixes such as an intersection, fix/radial/distance, and
latitude/longitude coordinates. Other electronic filing services may require a different format.
NOTE−
While user interfaces for flight plan filing are not specified, all flight plan filing services must adhere to the appropri -
ate Interface Control Document upon transmission of the flight plan to the control facility.
(b) When the intended destination (Item 16) is outside of domestic U.S. airspace, or if using the paper
version of FAA Form 7233−4, or if the chosen flight plan filing service does not allow non −ICAO airport
identifiers in Item 13 or Item 16, use the following ICAO procedure. Enter four Z’s (ZZZZ) in Item 13 and
include the non−ICAO airport location identifier, fix, or waypoint location in Item 18 DEP/. A text description
following the location identifier is permissible in Item 18 DEP/.
FAA Form 7233−4 − International Flight Plan Appendix 4−19
AIM 2/20/253/15/077110.65R CHG 2AIM 7/9/26
EXAMPLE−
DEST/06A MOTON FIELD
DEST/4AK6
DEST/MONTK
DEST /3925N07722W
8. Total Estimated Elapsed Time (Item 16)
All flight plans must include the total estimated elapsed time from departure to destination in hours (H) and
minutes (M), format HHMM.
9. Alternate Airport (Item 16, Item 18 ALTN/)
(a) When necessary, specify an alternate airport in Item 16 using the four−letter location identifier from FAA
Order 7350.9 or ICAO Document 7910. When the airport does not have a four−letter location identifier, include
ZZZZ in Item 16c and file the non−standard identifier in Item 18 ALTN/.
(b) While the FAA does not require filing of alternate airports in the flight plan provided to ATC, rules for
establishing alternate airports must be followed.
(c) Adding an alternate may assist during Search and Rescue by identifying additional areas to search.
(d) Although alternate airport information filed in a flight plan will be accepted by air traffic computer
systems, it will not be presented to controllers. If diversion to an alternate airport becomes necessary, pilots are
expected to notify ATC and request an amended clearance.
EXAMPLE−
ALTN/W50 2W2
10. Estimated Elapsed Times (EET) at boundaries or reporting points (Item 18 EET/)
EETs are required for international or oceanic flights when crossing a Flight Information Region (FIR) boundary.
The EET will include the ICAO four−letter location identifier for the FIR followed by the elapsed time to the
FIR boundary (e.g., KZNY0245 indicates 2 hours, 45 minutes from departure until the New York FIR boundary).
EXAMPLE−
EET/MMFR0011 MMTY0039 KZAB0105
11. Remarks (Item 18 RMK/)
Enter only those remarks pertinent to ATC or to the clarification of other flight plan information. Items of a
personal nature are not accepted.
NOTE−
1. “DVRSN” should be placed in Item 11 only if the pilot/company is requesting priority handling to their original
destination from ATC as a result of a diversion as defined in the Pilot/Controller Glossary.
2. Do not assume that remarks will be automatically transmitted to every controller. Specific ATC or en route requests
should be made directly to the appropriate controller.
g. Flight Specific Supplemental Information (Item 19)
1. Item 19 data must be included when completing FAA Form 7233−4. This information will be retained by
the facility/organization that transmits the flight plan to Air Traffic Control (ATC), for Search and Rescue
purposes, but it will not be transmitted to ATC as part of the flight plan.
2. Do not include Supplemental Information as part of Item 18. The information in Item 19 is retained with
the flight plan filing service for retrieval only if necessary.
NOTE−
Supplemental Information within Item 19 will be transmitted as a separate message to the destination FSS for VFR
flight plans filed with a FSS or F AA contracted flight plan filing service. This will reduce the time necessary to con-
duct SAR actions should the flight become overdue, as this information will be readily available to the destination
Flight Service Station.
3. Minimum required Item 19 entries for a domestic flight are Endurance, Persons on Board, Pilot Name and
Contact Information, and Color of Aircraft. Additional entries may be required by foreign air traffic services,
or at pilot discretion.
Appendix 4−20 FAA Form 7233−4 − International Flight Plan
AIM2/20/25
P/005
7/9/26 AIM
(a) After E/ Enter fuel endurance time in hours and minutes.
(b) After P/ Enter total number of persons on board using up to 30 alphanumeric characters. Enter TBN (to
be notified) if the total number of persons is not known at the time of filing.
EXAMPLE−
P/TBN
P/ON FILE CAPEAIR OPERATIONS
(c) R/ (Radio) Cross out items not carried
(d) S/ (Survival Equipment) Cross out items not carried.
(e) J/ (Jackets) Cross out items not carried.
(f) D/ (Life Raft/Dinghies) Enter number carried and total capacity. Indicate if covered and color.
(g) A/ (Aircraft Color and Markings) Enter aircraft color(s).
EXAMPLE−
White Yellow Blue
4. N/ (Remarks. Not for ATC) select N if no remarks. Enter comments concerning survival equipment and
information concerning personal GPS locating service, if utilized. Enter name and contact information for
responsible party to verify VFR arrival/closure, if desired. Ensure party will be available for contact at ETA. (for
example; FBO is open at ETA)
5. C/ (Pilot) Enter name and contact information, including telephone number, of pilot−in−command. Ensure
contact information will be valid at ETA in case SAR is necessary.
FAA Form 7233−4 − International Flight Plan Appendix 4−21
AIM 2/20/25
FIG 4−1
FAA Form 7233−4, Pre−Flight Pilot Checklist and International Flight Plan
Appendix 4−22 FAA Form 7233−4 − International Flight Plan
2/20/25 AIM
NOTE−
Current F AA Form 7233−4 available at https://www.faa.gov/forms/.
FAA Form 7233−4 − International Flight Plan Appendix 4−23
2/20/25 AIM
Appendix 5. FAA Form 7233−1 − Flight Plan
Throughout this document where references are made to FAA Form 7233−1, Flight Plan, and FAA Form 7233−4,
International Flight Plan, DoD use of the equivalent DoD Forms 175 and 1801 respectively, are implied and
acceptable. Within U.S. controlled air space, FAA Form 7233 −1, Flight Plan, may be used by filers of
DoD/military flight plans and civilian stereo route flight plans. Use of the international format flight plan format
is mandatory for:
a. Any flight plan filed through a FSS or FAA contracted flight plan filing service; with the exception of
Department of Defense flight plans and civilian stereo route flight plans, which can still be filed using the format
prescribed in FAA Form 7233−1.
NOTE−
DoD Form DD−175 and F AA Form 7233−1 are considered to follow the same format.
b. Any flight that will depart U.S. domestic airspace. For DoD flight plan purposes, offshore Warning Areas
may use FAA Form 7233−1 or military equivalent.
c. Any flight requesting routing that requires Performance Based Navigation.
d. Any flight requesting services that require filing of capabilities only supported in the international flight plan
format.
NOTE−
The order of flight plan elements in F AA Form 7233−1 is equivalent to the DD−175.
e. Explanation of IFR/VFR Flight Plan Items.
(1) Block 1. Check the type of flight plan.
(2) Block 2. Enter your complete aircraft identification.
(3) Block 3. Enter the aircraft type.
(4) Block 4. Enter the true airspeed (TAS).
(5) Block 5. Enter the departure airport identifier.
(6) Block 6. Enter the proposed departure time in Zulu (Z). If airborne, specify the actual or proposed
departure time as appropriate.
(7) Block 7. Enter the appropriate altitude.
(8) Block 8. Define the route of flight by using NA V AID identifier codes and airways.
(9) Block 9. Enter the destination airport identifier code.
(10) Block 10. Enter the estimated time en route in hours and minutes.
(11) Block 11. Enter remarks, if necessary.
(12) Block 12. Specify the fuel on board in hours and minutes.
(13) Block 13. Specify an alternate airport if desired.
(14) Block 14. Enter name and contact information for pilot in command.
NOTE−
This information is essential in the event of search and rescue operations.
(15) Block 15. Enter total number of persons on board (POB) including crew.
(16) Block 16. Enter the aircraft color.
FAA Form 7233−1 − Flight Plan Appendix 5−1
AIM 2/20/25
FIG 5−1
FAA Form 7233−1 − Flight Plan
For Military/DoD, Civilian Stereo Route Flight Plan Use Only
Appendix 5−2 FAA Form 7233−1 − Flight Plan
2/20/25 AIM
NOTE−
Current F AA Form 7233−1 available at https://www.faa.gov/forms/.
FAA Form 7233−1 − Flight Plan Appendix 5−3
Pilot/Controller Glossary7/9/26
PCG−1
PILOT/CONTROLLER
GLOSSARY
PURPOSE
a. This Glossary was compiled to promote a common understanding of the terms used in the Air Traffic
Control system. It includes those terms which are intended for pilot/controller communications. Those terms
most frequently used in pilot/controller communications are printed in bold italics. The definitions are primarily
defined in an operational sense applicable to both users and operators of the National Airspace System. Use of
the Glossary will preclude any misunderstandings concerning the system’s design, function, and purpose.
b. Because of the international nature of flying, terms used in the Lexicon, published by the International
Civil Aviation Organization (ICAO), are included when they differ from FAA definitions. These terms are
followed by “[ICAO].” For the reader’s convenience, there are also cross references to related terms in other parts
of the Glossary and to other documents, such as the Code of Federal Regulations (CFR) and the Aeronautical
Information Manual (AIM).
c. Terms used in this glossary that apply to flight service station (FSS) roles are included when they differ
from air traffic control functions. These terms are followed by “[FSS].”
d. This Glossary will be revised, as necessary, to maintain a common understanding of the system.
EXPLANATION OF CHANGES
e. Terms Added:
COMBINED CONTROL FACILITY (CCF)
f. Terms Deleted:
COMBINED CENTER−RAPCON (CERAP)
g. Terms Modified:
REMOTE COMMUNICATIONS AIR/GROUND FACILITY (RCAG)
SIMULTANEOUS (PARALLEL) DEPENDENT APPROACHES
h. Editorial/format changes were made where necessary. Revision bars were not used due to the insignificant
nature of the changes.
Pilot/Controller Glossary2/20/25
PCG A−1
AAM−
(See ADVANCED AIR MOBILITY.)
AAR−
(See AIRPORT ARRIVAL RATE.)
(See ADAPTED ROUTES.)
ABBREVIATED IFR FLIGHT PLANS − An authorization by ATC requiring pilots to submit only that
information needed for the purpose of ATC. It includes only a small portion of the usual IFR flight plan
information. In certain instances, this may be only aircraft identification, location, and pilot request. Other
information may be requested if needed by ATC for separation/control purposes. It is frequently used by aircraft
which are airborne and desire an instrument approach or by aircraft which are on the ground and desire a climb
to VFR-on-top.
(See VFR-ON-TOP.)
(Refer to AIM.)
ABEAM− An aircraft is “abeam” a fix, point, or object when that fix, point, or object is approximately 90 degrees
to the right or left of the aircraft track. Abeam indicates a general position rather than a precise point.
ABORT− To terminate a preplanned aircraft maneuver; e.g., an aborted takeoff.
ABRR−
(See AIRBORNE REROUTE)
AC−
(See ADVISORY CIRCULAR.)
ACC [ICAO]−
(See ICAO term AREA CONTROL CENTER.)
ACCELERATE-STOP DISTANCE A V AILABLE− The runway plus stopway length declared available and
suitable for the acceleration and deceleration of an airplane aborting a takeoff.
ACCELERATE-STOP DISTANCE A V AILABLE [ICAO]− The length of the take-off run available plus the
length of the stopway if provided.
ACDO−
(See AIR CARRIER DISTRICT OFFICE.)
ACKNOWLEDGE− Let me know that you have received and understood this message.
ACL−
(See AIRCRAFT LIST.)
ACLS−
(See AUTOMATIC CARRIER LANDING SYSTEM.)
ACROBATIC FLIGHT− An intentional maneuver involving an abrupt change in an aircraft’s attitude, an
abnormal attitude, or abnormal acceleration not necessary for normal flight.
(See ICAO term ACROBATIC FLIGHT.)
(Refer to 14 CFR part 91.)
ACROBATIC FLIGHT [ICAO]− Maneuvers intentionally performed by an aircraft involving an abrupt change
in its attitude, an abnormal attitude, or an abnormal variation in speed.
ACTIVE RUNWAY−
(See RUNWAY IN USE/ACTIVE RUNWAY/DUTY RUNWAY.)
Pilot/Controller Glossary 2/20/25
PCG A−2
ACTUAL NA VIGA TION PERFORMANCE (ANP)−
(See REQUIRED NAVIGATION PERFORMANCE.)
ADAPTED ROUTES− Departure and/or arrival routes that are adapted in ARTCC ERAM computers to
accomplish inter/intrafacility controller coordination and to ensure that flight data is posted at the proper control
positions. Adapted routes are automatically applied to flight plans where appropriate. When the workload or
traffic situation permits, controllers may provide radar vectors or assign requested routes to minimize circuitous
routing. Adapted routes are usually confined to one ARTCC’s area and are referred to by the following names
or abbreviations:
a. Adapted Arrival Route (AAR). A specific arrival route from an appropriate en route point to an airport or
terminal area. A Standard Terminal Arrival (STAR) and/or a partial Preferred IFR Route may be included in an
AAR.
b. Adapted Departure Route (ADR). A specific departure route from an airport or terminal area to an en route
point where there is no further need for flow control. An Instrument Departure Procedure (DP) and/or a partial
Preferred IFR Route may be included in an ADR.
c. Adapted Departure and Arrival Route (ADAR). A route between two terminals which are within or
immediately adjacent to one ARTCC’s area. ADARs are similar to Preferred IFR Routes and may share
components, but they are not synonymous.
(See PREFFERED IFR ROUTES.)
ADAR−
(See ADAPTED ROUTES.)
ADDITIONAL SERVICES− Advisory information provided by ATC which includes but is not limited to the
following:
a. Traffic advisories.
b. Vectors, when requested by the pilot, to assist aircraft receiving traffic advisories to avoid observed traffic.
c. Altitude deviation information of 300 feet or more from an assigned altitude as observed on a verified
(reading correctly) automatic altitude readout (Mode C).
d. Advisories that traffic is no longer a factor.
e. Weather and chaff information.
f. Weather assistance.
g. Bird activity information.
h. Holding pattern surveillance. Additional services are provided to the extent possible contingent only upon
the controller’s capability to fit them into the performance of higher priority duties and on the basis of limitations
of the radar, volume of traffic, frequency congestion, and controller workload. The controller has complete
discretion for determining if he/she is able to provide or continue to provide a service in a particular case. The
controller’s reason not to provide or continue to provide a service in a particular case is not subject to question
by the pilot and need not be made known to him/her.
(See TRAFFIC ADVISORIES.)
(Refer to AIM.)
ADF−
(See AUTOMATIC DIRECTION FINDER.)
ADIZ−
(See AIR DEFENSE IDENTIFICATION ZONE.)
ADLY−
(See ARRIVAL DELAY.)
ADMINISTRATOR− The Federal Aviation Administrator or any person to whom he/she has delegated his/her
authority in the matter concerned.
Pilot/Controller Glossary2/20/25
PCG A−3
ADR−
(See ADAPTED ROUTES.)
(See AIRPORT DEPARTURE RATE.)
ADS [ICAO]−
(See ICAO term AUTOMATIC DEPENDENT SURVEILLANCE.)
ADS−B−
(See AUTOMATIC DEPENDENT SURVEILLANCE−BROADCAST.)
ADS−C−
(See AUTOMATIC DEPENDENT SURVEILLANCE−CONTRACT.)
ADV ANCED AIR MOBILITY (AAM)−A transportation system that transports people and property by air
between two points in the NAS using aircraft with advanced technologies, including electric aircraft or electric
vertical takeoff and landing aircraft, in both controlled and uncontrolled airspace.
ADVISE INTENTIONS− Tell me what you plan to do.
ADVISORY− Advice and information provided to assist pilots in the safe conduct of flight and aircraft
movement.
(See ADVISORY SERVICE.)
ADVISORY CIRCULAR (AC) − An FAA publication, advisory and descriptive in nature, which is not
regulatory.
ADVISORY FREQUENCY− The appropriate frequency to be used for Airport Advisory Service.
(See LOCAL AIRPORT ADVISORY.)
(See UNICOM.)
(Refer to ADVISORY CIRCULAR NO. 90-66.)
(Refer to AIM.)
ADVISORY SERVICE− Advice and information provided by a facility to assist pilots in the safe conduct of
flight and aircraft movement.
(See ADDITIONAL SERVICES.)
(See LOCAL AIRPORT ADVISORY.)
(See RADAR ADVISORY.)
(See SAFETY ALERT.)
(See TRAFFIC ADVISORIES.)
(Refer to AIM.)
ADW−
(See ARRIVAL DEPARTURE WINDOW)
AERIAL REFUELING− A procedure used by the military to transfer fuel from one aircraft to another during
flight.
(Refer to VFR/IFR Wall Planning Charts.)
AERODROME− A defined area on land or water (including any buildings, installations and equipment)
intended to be used either wholly or in part for the arrival, departure, and movement of aircraft.
AERODROME BEACON [ICAO]− Aeronautical beacon used to indicate the location of an aerodrome from
the air.
AERODROME CONTROL SERVICE [ICAO]− Air traffic control service for aerodrome traffic.
AERODROME CONTROL TOWER [ICAO] − A unit established to provide air traffic control service to
aerodrome traffic.
AERODROME ELEV ATION [ICAO]− The elevation of the highest point of the landing area.
Pilot/Controller Glossary 2/20/25
PCG A−4
AERODROME TRAFFIC CIRCUIT [ICAO] − The specified path to be flown by aircraft operating in the
vicinity of an aerodrome.
AERONAUTICAL BEACON− A visual NA V AID displaying flashes of white and/or colored light to indicate
the location of an airport, a heliport, a landmark, a certain point of a Federal airway in mountainous terrain, or
an obstruction.
(See AIRPORT ROTATING BEACON.)
(Refer to AIM.)
AERONAUTICAL CHART− A map used in air navigation containing all or part of the following: topographic
features, hazards and obstructions, navigation aids, navigation routes, designated airspace, and airports.
Commonly used aeronautical charts are:
a. Sectional Aeronautical Charts (1:500,000) − Designed for visual navigation of slow or medium speed
aircraft. Topographic information on these charts features the portrayal of relief and a judicious selection of
visual check points for VFR flight. Aeronautical information includes visual and radio aids to navigation,
airports, controlled airspace, permanent special use airspace (SUA), obstructions, and related data.
b. VFR Terminal Area Charts (1:250,000) − Depict Class B airspace which provides for the control or
segregation of all the aircraft within Class B airspace. The chart depicts topographic information and aeronautical
information which includes visual and radio aids to navigation, airports, controlled airspace, permanent SUA,
obstructions, and related data.
c. En Route Low Altitude Charts− Provide aeronautical information for en route instrument navigation (IFR)
in the low altitude stratum. Information includes the portrayal of airways, limits of controlled airspace, position
identification and frequencies of radio aids, selected airports, minimum en route and minimum obstruction
clearance altitudes, airway distances, reporting points, permanent SUA, and related data. Area charts, which are
a part of this series, furnish terminal data at a larger scale in congested areas.
d. En Route High Altitude Charts− Provide aeronautical information for en route instrument navigation (IFR)
in the high altitude stratum. Information includes the portrayal of jet routes, identification and frequencies of
radio aids, selected airports, distances, time zones, special use airspace, and related information.
e. Instrument Approach Procedure (IAP) Charts− Portray the aeronautical data which is required to execute
an instrument approach to an airport. These charts depict the procedures, including all related data, and the airport
diagram. Each procedure is designated for use with a specific type of electronic navigation system including
NDB, TACAN, VOR, ILS RNA V and GLS. These charts are identified by the type of navigational
aid(s)/equipment required to provide final approach guidance.
f. Instrument Departure Procedure (DP) Charts− Designed to expedite clearance delivery and to facilitate
transition between takeoff and en route operations. Each DP is presented as a separate chart and may serve a
single airport or more than one airport in a given geographical location.
g. Standard Terminal Arrival (STAR) Charts− Designed to expedite air traffic control arrival procedures and
to facilitate transition between en route and instrument approach operations. Each STAR procedure is presented
as a separate chart and may serve a single airport or more than one airport in a given geographical location.
h. Airport Taxi Charts− Designed to expedite the efficient and safe flow of ground traffic at an airport. These
charts are identified by the official airport name; e.g., Ronald Reagan Washington National Airport.
(See ICAO term AERONAUTICAL CHART.)
AERONAUTICAL CHART [ICAO] − A representation of a portion of the earth, its culture and relief,
specifically designated to meet the requirements of air navigation.
AERONAUTICAL INFORMATION MANUAL (AIM)− A primary FAA publication whose purpose is to
instruct airmen about operating in the National Airspace System of the U.S. It provides basic flight information,
ATC Procedures and general instructional information concerning health, medical facts, factors affecting flight
safety, accident and hazard reporting, and types of aeronautical charts and their use.
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PCG A−5
AERONAUTICAL INFORMATION PUBLICATION (AIP) [ICAO] − A publication issued by or with the
authority of a State and containing aeronautical information of a lasting character essential to air navigation.
(See CHART SUPPLEMENT.)
AERONAUTICAL INFORMATION SERVICES (AIS)− A facility in Silver Spring, MD, established by FAA
to operate a central aeronautical information service for the collection, validation, and dissemination of
aeronautical data in support of the activities of government, industry, and the aviation community. The
information is published in the National Flight Data Digest.
(See NATIONAL FLIGHT DATA DIGEST.)
AFFIRMATIVE− Yes.
AFIS−
(See AUTOMATIC FLIGHT INFORMATION SERVICE − ALASKA FSSs ONLY.)
AFP−
(See AIRSPACE FLOW PROGRAM.)
AHA−
(See AIRCRAFT HAZARD AREA.)
AIM−
(See AERONAUTICAL INFORMATION MANUAL.)
AIP [ICAO]−
(See ICAO term AERONAUTICAL INFORMATION PUBLICATION.)
AIR CARRIER DISTRICT OFFICE− An FAA field office serving an assigned geographical area, staffed with
Flight Standards personnel serving the aviation industry and the general public on matters related to the
certification and operation of scheduled air carriers and other large aircraft operations.
AIR DEFENSE EMERGENCY− A military emergency condition declared by a designated authority. This
condition exists when an attack upon the continental U.S., Alaska, Canada, or U.S. installations in Greenland
by hostile aircraft or missiles is considered probable, is imminent, or is taking place.
(Refer to AIM.)
AIR DEFENSE IDENTIFICATION ZONE (ADIZ)− An area of airspace over land or water in which the ready
identification, location, and control of all aircraft (except for Department of Defense and law enforcement
aircraft) is required in the interest of national security.
Note: ADIZ locations and operating and flight plan requirements for civil aircraft operations are specified in
14 CFR part 99.
(Refer to AIM.)
AIR NA VIGA TION FACILITY− Any facility used in, available for use in, or designed for use in, aid of air
navigation, including landing areas, lights, any apparatus or equipment for disseminating weather information,
for signaling, for radio-directional finding, or for radio or other electrical communication, and any other structure
or mechanism having a similar purpose for guiding or controlling flight in the air or the landing and takeoff of
aircraft.
(See NAVIGATIONAL AID.)
AIR ROUTE SURVEILLANCE RADAR− Air route traffic control center (ARTCC) radar used primarily to
detect and display an aircraft’s position while en route between terminal areas. The ARSR enables controllers
to provide radar air traffic control service when aircraft are within the ARSR coverage. In some instances, ARSR
may enable an ARTCC to provide terminal radar services similar to but usually more limited than those provided
by a radar approach control.
AIR ROUTE TRAFFIC CONTROL CENTER (ARTCC)− A facility established to provide air traffic control
service to aircraft operating on IFR flight plans within controlled airspace and principally during the en route
Pilot/Controller Glossary 2/20/25
PCG A−6
phase of flight. When equipment capabilities and controller workload permit, certain advisory/assistance
services may be provided to VFR aircraft.
(See EN ROUTE AIR TRAFFIC CONTROL SERVICES.)
(Refer to AIM.)
AIR TAXI− Used to describe a helicopter/VTOL aircraft movement conducted above the surface but normally
not above 100 feet AGL. The aircraft may proceed either via hover taxi or flight at speeds more than 20 knots.
The pilot is solely responsible for selecting a safe airspeed/altitude for the operation being conducted.
(See HOVER TAXI.)
(Refer to AIM.)
AIR TRAFFIC− Aircraft operating in the air or on an airport surface, exclusive of loading ramps and parking
areas.
(See ICAO term AIR TRAFFIC.)
AIR TRAFFIC [ICAO]− All aircraft in flight or operating on the maneuvering area of an aerodrome.
AIR TRAFFIC CLEARANCE− An authorization by air traffic control for the purpose of preventing collision
between known aircraft, for an aircraft to proceed under specified traffic conditions within controlled airspace.
The pilot-in-command of an aircraft may not deviate from the provisions of a visual flight rules (VFR) or
instrument flight rules (IFR) air traffic clearance except in an emergency or unless an amended clearance has
been obtained. Additionally, the pilot may request a different clearance from that which has been issued by air
traffic control (ATC) if information available to the pilot makes another course of action more practicable or if
aircraft equipment limitations or company procedures forbid compliance with the clearance issued. Pilots may
also request clarification or amendment, as appropriate, any time a clearance is not fully understood, or
considered unacceptable because of safety of flight. Controllers should, in such instances and to the extent of
operational practicality and safety, honor the pilot’s request. 14 CFR part 91.3(a) states: “The pilot in command
of an aircraft is directly responsible for, and is the final authority as to, the operation of that aircraft.” THE PILOT
IS RESPONSIBLE TO REQUEST AN AMENDED CLEARANCE if ATC issues a clearance that would cause
a pilot to deviate from a rule or regulation, or in the pilot’s opinion, would place the aircraft in jeopardy.
(See ATC INSTRUCTIONS.)
(See ICAO term AIR TRAFFIC CONTROL CLEARANCE.)
AIR TRAFFIC CONTROL− A service operated by appropriate authority to promote the safe, orderly and
expeditious flow of air traffic.
(See ICAO term AIR TRAFFIC CONTROL SERVICE.)
AIR TRAFFIC CONTROL CLEARANCE [ICAO]− Authorization for an aircraft to proceed under conditions
specified by an air traffic control unit.
Note 1: For convenience, the term air traffic control clearance is frequently abbreviated to clearance when
used in appropriate contexts.
Note 2: The abbreviated term clearance may be prefixed by the words taxi, takeoff, departure, en route,
approach or landing to indicate the particular portion of flight to which the air traffic control clearance relates.
AIR TRAFFIC CONTROL SERVICE−
(See AIR TRAFFIC CONTROL.)
AIR TRAFFIC CONTROL SERVICE [ICAO]− A service provided for the purpose of:
a. Preventing collisions:
1. Between aircraft; and
2. On the maneuvering area between aircraft and obstructions.
b. Expediting and maintaining an orderly flow of air traffic.
AIR TRAFFIC CONTROL SPECIALIST− A person authorized to provide air traffic control service.
(See AIR TRAFFIC CONTROL.)
(See FLIGHT SERVICE STATION.)
(See ICAO term CONTROLLER.)
Pilot/Controller Glossary2/20/25
PCG A−7
AIR TRAFFIC CONTROL SYSTEM COMMAND CENTER (ATCSCC)− An Air Traffic Tactical Operations
facility responsible for monitoring and managing the flow of air traffic throughout the NAS, producing a safe,
orderly, and expeditious flow of traffic while minimizing delays. The following functions are located at the
ATCSCC:
a. Central Altitude Reservation Function (CARF). Responsible for coordinating, planning, and approving
special user requirements under the Altitude Reservation (ALTRV) concept.
(See ALTITUDE RESERVATION.)
b. Airport Reservation Office (ARO). Monitors the operation and allocation of reservations for unscheduled
operations at airports designated by the Administrator as High Density Airports. These airports are generally
known as slot controlled airports. The ARO allocates reservations on a first come, first served basis determined
by the time the request is received at the ARO.
(Refer to 14 CFR part 93.)
(See CHART SUPPLEMENT.)
c. U.S. Notice to Airmen (NOTAM) Office. Responsible for collecting, maintaining, and distributing
NOTAMs for the U.S. civilian and military, as well as international aviation communities.
(See NOTICE TO AIRMEN.)
d. Weather Unit. Monitor all aspects of weather for the U.S. that might affect aviation including cloud cover,
visibility, winds, precipitation, thunderstorms, icing, turbulence, and more. Provide forecasts based on
observations and on discussions with meteorologists from various National Weather Service offices, FAA
facilities, airlines, and private weather services.
e. Air Traffic Organization (ATO) Space Operations and Unmanned Aircraft System (UAS); the Office of
Primary Responsibility (OPR) for all space and upper class E tactical operations in the National Airspace System
(NAS).
AIR TRAFFIC SERVICE− A generic term meaning:
a. Flight Information Service.
b. Alerting Service.
c. Air Traffic Advisory Service.
d. Air Traffic Control Service:
1. Area Control Service,
2. Approach Control Service, or
3. Airport Control Service.
AIR TRAFFIC ORGANIZATION (ATO) − The FAA line of business responsible for providing safe and efficient
air navigation services in the national airspace system.
AIR TRAFFIC SERVICE (ATS) ROUTES − The term “ATS Route” is a generic term that includes “VOR
Federal airways,” “colored Federal airways,” “jet routes,” and “RNA V routes.” The term “ATS route” does not
replace these more familiar route names, but serves only as an overall title when listing the types of routes that
comprise the United States route structure.
AIRBORNE− An aircraft is considered airborne when all parts of the aircraft are off the ground.
AIRBORNE DELAY− Amount of delay to be encountered in airborne holding.
AIRBORNE REROUTE (ABRR)− A capability within the Traffic Flow Management System used for the
timely development and implementation of tactical reroutes for airborne aircraft. This capability defines a set
of aircraft−specific reroutes that address a certain traffic flow problem and then electronically transmits them
to En Route Automation Modernization (ERAM) for execution by the appropriate sector controllers.
AIRCRAFT− Device(s) that are used or intended to be used for flight in the air, and when used in air traffic
control terminology, may include the flight crew. The term is inclusive of all types, including but not limited
to, airplane, glider, lighter-than-air, powered-lift, and rotorcraft.
(See ICAO term AIRCRAFT.)
8/7/25 Pilot/Controller Glossary
Pilot/Controller Glossary 2/20/25
PCG A−8
AIRCRAFT [ICAO]− Any machine that can derive support in the atmosphere from the reactions of the air other
than the reactions of the air against the earth’s surface.
AIRCRAFT APPROACH CATEGORY− A grouping of aircraft based on a speed of 1.3 times the stall speed
in the landing configuration at maximum gross landing weight. An aircraft must fit in only one category. If it
is necessary to maneuver at speeds in excess of the upper limit of a speed range for a category, the minimums
for the category for that speed must be used. For example, an aircraft which falls in Category A, but is circling
to land at a speed in excess of 91 knots, must use the approach Category B minimums when circling to land.
The categories are as follows:
a. Category A− Speed less than 91 knots.
b. Category B− Speed 91 knots or more but less than 121 knots.
c. Category C− Speed 121 knots or more but less than 141 knots.
d. Category D− Speed 141 knots or more but less than 166 knots.
e. Category E− Speed 166 knots or more.
(Refer to 14 CFR part 97.)
AIRCRAFT CLASSES− For the purposes of Wake Turbulence Separation Minima, ATC classifies aircraft as
Super, Heavy, Large, and Small as follows:
a. Super− The Airbus A−380−800 (A388) is classified as a super aircraft. A super aircraft is a Category A for
terminal wake turbulence separation purposes.
b. Heavy− Aircraft capable of takeoff weights of 300,000 pounds or more whether or not they are operating
at this weight during a particular phase of flight. Heavy aircraft are Category B, C, or D for terminal wake
turbulence separation purposes.
c. Large− Aircraft of more than 41,000 pounds, maximum certificated takeoff weight, up to but not including
300,000 pounds. Large aircraft are Category F and G for terminal wake turbulence separation purposes.
d. Small− Aircraft of 41,000 pounds or less maximum certificated takeoff weight. Small aircraft are Category
H and I for terminal wake turbulence separation purposes.
(Refer to AIM.)
AIRCRAFT CONFLICT− Predicted conflict, within EDST of two aircraft, or between aircraft and airspace. A
Red alert is used for conflicts when the predicted minimum separation is 5 nautical miles or less. A Yellow alert
is used when the predicted minimum separation is between 5 and approximately 12 nautical miles. A Blue alert
is used for conflicts between an aircraft and predefined airspace.
(See EN ROUTE DECISION SUPPORT TOOL.)
AIRCRAFT HAZARD AREA (AHA)− Used by ATC to segregate air traffic from a launch vehicle, reentry
vehicle, amateur rocket, jettisoned stages, hardware, or falling debris generated by failures associated with any
of these activities. An AHA is designated via NOTAM as either a TFR or stationary ALTRV . Unless otherwise
specified, the vertical limits of an AHA are from the surface to unlimited.
(See CONTINGENCY HAZARD AREA.)
(See REFINED HAZARD AREA.)
(See TRANSITIONAL HAZARD AREA.)
AIRCRAFT LIST (ACL)− A view available with EDST that lists aircraft currently in or predicted to be in a
particular sector’s airspace. The view contains textual flight data information in line format and may be sorted
into various orders based on the specific needs of the sector team.
(See EN ROUTE DECISION SUPPORT TOOL.)
AIRCRAFT SURGE LAUNCH AND RECOVERY − Procedures used at USAF bases to provide increased
launch and recovery rates in instrument flight rules conditions. ASLAR is based on:
Pilot/Controller Glossary 1/22/26
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PCG A−9
a. Reduced separation between aircraft which is based on time or distance. Standard arrival separation applies
between participants including multiple flights until the DRAG point. The DRAG point is a published location
on an ASLAR approach where aircraft landing second in a formation slows to a predetermined airspeed. The
DRAG point is the reference point at which MARSA applies as expanding elements effect separation within a
flight or between subsequent participating flights.
b. ASLAR procedures must be covered in a Letter of Agreement between the responsible USAF military ATC
facility and the concerned Federal Aviation Administration facility. Initial Approach Fix spacing requirements
are normally addressed as a minimum.
AIRCRAFT W AKE CATEGORIES− For the purposes of Terminal Wake Turbulence Separation Minima, ATC
classifies aircraft as Category A through Category I as follows:
a. CATEGORY A. The Airbus A−380−800 (A388) is classified as a super aircraft.
b. CATEGORY B, C, and D. Aircraft capable of takeoff weights of 300,000 pounds or more whether or not
they are operating at this weight during a particular phase of flight. These are categorized as heavy aircraft.
c. CATEGORY E. All B757 aircraft.
d. CATEGORY F, and G. Aircraft weighing 41,000 pounds or more maximum certificated takeoff weight,
up to but not including 300,000 pounds.
e. CATEGORY H and I. Aircraft of less than 41,000 pounds maximum certificated takeoff weight.
(Refer to AIM.)
AIRMEN’S METEOROLOGICAL INFORMATION (AIRMET)− A concise description of an occurrence or
expected occurrence of specified en route weather phenomena that may affect the safety of aircraft operations,
but at intensities lower than those that require the issuance of a SIGMET. An AIRMET may be issued when any
of the following weather phenomena are occurring or expected to occur:
a. Moderate turbulence
b. Low−level windshear
c. Strong surface winds greater than 30 knots
d. Moderate icing
e. Freezing level
f. Mountain obscuration
g. IFR
(See CONVECTIVE SIGMET.)
(See CWA.)
(See GRAPHICAL AIRMEN’S METEOROLOGICAL INFORMATION.)
(See SAW.)
(See SIGMET.)
(Refer to AIM.)
AIRPLANE− An engine-driven fixed-wing aircraft heavier than air that is supported in flight by the dynamic
reaction of the air against its wings.
AIRPORT− An area on land or water that is used or intended to be used for the landing and takeoff of aircraft
and includes its buildings and facilities, if any.
AIRPORT ADVISORY AREA− The area within ten miles of an airport without a control tower or where the
tower is not in operation, and on which a Flight Service Station is located.
(See LOCAL AIRPORT ADVISORY.)
(Refer to AIM.)
AIRPORT ARRIV AL RATE (AAR)− A dynamic input parameter specifying the number of arriving aircraft
which an airport or airspace can accept from the ARTCC per hour. The AAR is used to calculate the desired
interval between successive arrival aircraft.
1/22/26 Pilot/Controller Glossary
Pilot/Controller Glossary 2/20/25
PCG A−10
AIRPORT DEPARTURE RATE (ADR)− A dynamic parameter specifying the number of aircraft which can
depart an airport and the airspace can accept per hour.
AIRPORT ELEV ATION− The highest point of an airport’s usable runways measured in feet from mean sea level.
(See TOUCHDOWN ZONE ELEVATION.)
(See ICAO term AERODROME ELEVATION.)
AIRPORT LIGHTING− Various lighting aids that may be installed on an airport. Types of airport lighting
include:
a. Approach Light System (ALS)− An airport lighting facility which provides visual guidance to landing
aircraft by radiating light beams in a directional pattern by which the pilot aligns the aircraft with the extended
centerline of the runway on his/her final approach for landing. Condenser-Discharge Sequential Flashing
Lights/Sequenced Flashing Lights may be installed in conjunction with the ALS at some airports. Types of
Approach Light Systems are:
1. ALSF-1− Approach Light System with Sequenced Flashing Lights in ILS Cat-I configuration.
2. ALSF-2− Approach Light System with Sequenced Flashing Lights in ILS Cat-II configuration. The
ALSF-2 may operate as an SSALR when weather conditions permit.
3. SSALF− Simplified Short Approach Light System with Sequenced Flashing Lights.
4. SSALR− Simplified Short Approach Light System with Runway Alignment Indicator Lights.
5. MALSF− Medium Intensity Approach Light System with Sequenced Flashing Lights.
6. MALSR− Medium Intensity Approach Light System with Runway Alignment Indicator Lights.
7. RLLS− Runway Lead-in Light System Consists of one or more series of flashing lights installed at or
near ground level that provides positive visual guidance along an approach path, either curving or straight, where
special problems exist with hazardous terrain, obstructions, or noise abatement procedures.
8. RAIL− Runway Alignment Indicator Lights− Sequenced Flashing Lights which are installed only in
combination with other light systems.
9. ODALS− Omnidirectional Approach Lighting System consists of seven omnidirectional flashing lights
located in the approach area of a nonprecision runway. Five lights are located on the runway centerline extended
with the first light located 300 feet from the threshold and extending at equal intervals up to 1,500 feet from the
threshold. The other two lights are located, one on each side of the runway threshold, at a lateral distance of 40
feet from the runway edge, or 75 feet from the runway edge when installed on a runway equipped with a V ASI.
(Refer to FAA Order JO 6850.2, Visual Guidance Lighting Systems.)
b. Runway Lights/Runway Edge Lights− Lights having a prescribed angle of emission used to define the
lateral limits of a runway. Runway lights are uniformly spaced at intervals of approximately 200 feet, and the
intensity may be controlled or preset.
c. Touchdown Zone Lighting− Two rows of transverse light bars located symmetrically about the runway
centerline normally at 100 foot intervals. The basic system extends 3,000 feet along the runway.
d. Runway Centerline Lighting− Flush centerline lights spaced at 50-foot intervals beginning 75 feet from
the landing threshold and extending to within 75 feet of the opposite end of the runway.
e. Threshold Lights− Fixed green lights arranged symmetrically left and right of the runway centerline,
identifying the runway threshold.
f. Runway End Identifier Lights (REIL)− Two synchronized flashing lights, one on each side of the runway
threshold, which provide rapid and positive identification of the approach end of a particular runway.
g. Visual Approach Slope Indicator (V ASI)− An airport lighting facility providing vertical visual approach
slope guidance to aircraft during approach to landing by radiating a directional pattern of high intensity red and
white focused light beams which indicate to the pilot that he/she is “on path” if he/she sees red/white, “above
path” if white/white, and “below path” if red/red. Some airports serving large aircraft have three-bar V ASIs
which provide two visual glide paths to the same runway.
h. Precision Approach Path Indicator (PAPI)− An airport lighting facility, similar to VASI, providing vertical
approach slope guidance to aircraft during approach to landing. PAPIs consist of a single row of either two or
Pilot/Controller Glossary 1/22/26
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PCG A−11
four lights, normally installed on the left side of the runway, and have an effective visual range of about 5 miles
during the day and up to 20 miles at night. PAPIs radiate a directional pattern of high intensity red and white
focused light beams which indicate that the pilot is “on path” if the pilot sees an equal number of white lights
and red lights, with white to the left of the red; “above path” if the pilot sees more white than red lights; and
“below path” if the pilot sees more red than white lights.
i. Boundary Lights− Lights defining the perimeter of an airport or landing area.
(Refer to AIM.)
AIRPORT MARKING AIDS− Markings used on runway and taxiway surfaces to identify a specific runway,
a runway threshold, a centerline, a hold line, etc. A runway should be marked in accordance with its present usage
such as:
a. Visual.
b. Nonprecision instrument.
c. Precision instrument.
(Refer to AIM.)
AIRPORT REFERENCE POINT (ARP)− The approximate geometric center of all usable runway surfaces.
AIRPORT RESERV ATION OFFICE− Office responsible for monitoring the operation of slot controlled
airports. It receives and processes requests for unscheduled operations at slot controlled airports.
AIRPORT ROTATING BEACON− A visual NA V AID operated at many airports. At civil airports, alternating
white and green flashes indicate the location of the airport. At military airports, the beacons flash alternately
white and green, but are differentiated from civil beacons by dualpeaked (two quick) white flashes between the
green flashes.
(See INSTRUMENT FLIGHT RULES.)
(See SPECIAL VFR OPERATIONS.)
(See ICAO term AERODROME BEACON.)
(Refer to AIM.)
AIRPORT SURFACE DETECTION EQUIPMENT (ASDE)− Surveillance equipment specifically designed to
detect aircraft, vehicular traffic, and other objects, on the surface of an airport, and to present the image on a tower
display. Used to augment visual observation by tower personnel of aircraft and/or vehicular movements on
runways and taxiways. There are three ASDE systems deployed in the NAS:
a. ASDE−3− a Surface Movement Radar.
b. ASDE−X− a system that uses an X−band Surface Movement Radar, multilateration, and ADS−B.
c. Airport Surface Surveillance Capability (ASSC) − A system that uses Surface Movement Radar,
multilateration, and ADS−B.
AIRPORT SURVEILLANCE RADAR− Approach control radar used to detect and display an aircraft’s position
in the terminal area. ASR provides range and azimuth information but does not provide elevation data. Coverage
of the ASR can extend up to 60 miles.
AIRPORT TAXI CHARTS−
(See AERONAUTICAL CHART.)
AIRPORT TRAFFIC CONTROL SERVICE− A service provided by a control tower for aircraft operating on
the movement area and in the vicinity of an airport.
(See MOVEMENT AREA.)
(See TOWER.)
(See ICAO term AERODROME CONTROL SERVICE.)
AIRPORT TRAFFIC CONTROL TOWER−
(See TOWER.)
AIRSPACE CONFLICT− Predicted conflict of an aircraft and active Special Activity Airspace (SAA).
1/22/26 Pilot/Controller Glossary
Pilot/Controller Glossary 2/20/25
PCG A−12
AIRSPACE FLOW PROGRAM (AFP)− AFP is a Traffic Management (TM) process administered by the Air
Traffic Control System Command Center (ATCSCC) where aircraft are assigned an Expect Departure Clearance
Time (EDCT) in order to manage capacity and demand for a specific area of the National Airspace System
(NAS). The purpose of the program is to mitigate the effects of en route constraints. It is a flexible program and
may be implemented in various forms depending upon the needs of the air traffic system.
AIRSPACE HIERARCHY− Within the airspace classes, there is a hierarchy and, in the event of an overlap of
airspace: Class A preempts Class B, Class B preempts Class C, Class C preempts Class D, Class D preempts
Class E, and Class E preempts Class G.
AIRSPEED− The speed of an aircraft relative to its surrounding air mass. The unqualified term “airspeed” means
one of the following:
a. Indicated Airspeed− The speed shown on the aircraft airspeed indicator. This is the speed used in
pilot/controller communications under the general term “airspeed.”
(Refer to 14 CFR part 1.)
b. True Airspeed− The airspeed of an aircraft relative to undisturbed air. Used primarily in flight planning
and en route portion of flight. When used in pilot/controller communications, it is referred to as “true airspeed”
and not shortened to “airspeed.”
AIRSPACE RESERV ATION− The term used in oceanic ATC for airspace utilization under prescribed conditions
normally employed for the mass movement of aircraft or other special user requirements which cannot otherwise
be accomplished. Airspace reservations must be classified as either “moving” or “stationary.”
(See MOVING AIRSPACE RESERVATION)
(See STATIONARY AIRSPACE RESERVATION.)
(See ALTITUDE RESERVATION.)
AIRSTART− The starting of an aircraft engine while the aircraft is airborne, preceded by engine shutdown during
training flights or by actual engine failure.
AIRWAY− A Class E airspace area established in the form of a corridor, the centerline of which is defined by
radio navigational aids.
(See FEDERAL AIRWAYS.)
(See ICAO term AIRWAY.)
(Refer to 14 CFR part 71.)
(Refer to AIM.)
AIRWAY [ICAO]− A control area or portion thereof established in the form of corridor equipped with radio
navigational aids.
AIRWAY BEACON− Used to mark airway segments in remote mountain areas. The light flashes Morse Code
to identify the beacon site.
(Refer to AIM.)
AIS−
(See AERONAUTICAL INFORMATION SERVICES.)
AIT−
(See AUTOMATED INFORMATION TRANSFER.)
ALERFA (Alert Phase) [ICAO]− A situation wherein apprehension exists as to the safety of an aircraft and its
occupants.
ALERT− A notification to a position that there is an aircraft-to-aircraft or aircraft-to-airspace conflict,
as detected by Automated Problem Detection (APD).
ALERT AREA−
(See SPECIAL USE AIRSPACE.)
Pilot/Controller Glossary 1/22/26
Pilot/Controller Glossary2/20/25
PCG A−13
ALERT NOTICE (ALNOT)− A request originated by a flight service station (FSS) or an air route traffic control
center (ARTCC) for an extensive communication search for overdue, unreported, or missing aircraft.
ALERTING SERVICE− A service provided to notify appropriate organizations regarding aircraft in need of
search and rescue aid and assist such organizations as required.
ALNOT−
(See ALERT NOTICE.)
ALONG−TRACK DISTANCE (ATD)− The horizontal distance between the aircraft’s current position and a fix
measured by an area navigation system that is not subject to slant range errors.
ALPHANUMERIC DISPLAY− Letters and numerals used to show identification, altitude, beacon code, and
other information concerning a target on a radar display.
ALTERNATE AERODROME [ICAO]− An aerodrome to which an aircraft may proceed when it becomes either
impossible or inadvisable to proceed to or to land at the aerodrome of intended landing.
Note: The aerodrome from which a flight departs may also be an en-route or a destination alternate aerodrome
for the flight.
ALTERNATE AIRPORT− An airport at which an aircraft may land if a landing at the intended airport becomes
inadvisable.
(See ICAO term ALTERNATE AERODROME.)
ALTIMETER SETTING− The barometric pressure reading used to adjust a pressure altimeter for variations in
existing atmospheric pressure or to the standard altimeter setting (29.92).
(Refer to 14 CFR part 91.)
(Refer to AIM.)
ALTITUDE− The height of a level, point, or object measured in feet Above Ground Level (AGL) or from Mean
Sea Level (MSL).
(See FLIGHT LEVEL.)
a. MSL Altitude− Altitude expressed in feet measured from mean sea level.
b. AGL Altitude− Altitude expressed in feet measured above ground level.
c. Indicated Altitude− The altitude as shown by an altimeter. On a pressure or barometric altimeter it is altitude
as shown uncorrected for instrument error and uncompensated for variation from standard atmospheric
conditions.
(See ICAO term ALTITUDE.)
ALTITUDE [ICAO]− The vertical distance of a level, a point or an object considered as a point, measured from
mean sea level (MSL).
ALTITUDE READOUT− An aircraft’s altitude, transmitted via the Mode C transponder feature, that is visually
displayed in 100-foot increments on a radar scope having readout capability.
(See ALPHANUMERIC DISPLAY.)
(Refer to AIM.)
ALTITUDE RESERV ATION (ALTRV)− Airspace utilization under prescribed conditions normally employed
for the mass movement of aircraft or other special user requirements which cannot otherwise be accomplished.
ALTRVs are approved by the appropriate FAA facility. ALTRVs must be classified as either “moving” or
“stationary.”
(See MOVING ALTITUDE RESERVATION.)
(See STATIONARY ALTITUDE RESERVATION.)
(See AIR TRAFFIC CONTROL SYSTEM COMMAND CENTER.)
ALTITUDE RESTRICTION− An altitude or altitudes, stated in the order flown, which are to be maintained until
reaching a specific point or time. Altitude restrictions may be issued by ATC due to traffic, terrain, or other
airspace considerations.
1/22/26 Pilot/Controller Glossary
Pilot/Controller Glossary 2/20/25
PCG A−14
ALTITUDE RESTRICTIONS ARE CANCELED − Adherence to previously imposed altitude restrictions is
no longer required during a climb or descent.
ALTRV−
(See ALTITUDE RESERVATION.)
AMVER−
(See AUTOMATED MUTUAL-ASSISTANCE VESSEL RESCUE SYSTEM.)
APB−
(See AUTOMATED PROBLEM DETECTION BOUNDARY.)
APD−
(See AUTOMATED PROBLEM DETECTION.)
APDIA−
(See AUTOMATED PROBLEM DETECTION INHIBITED AREA.)
APPROACH CLEARANCE− Authorization by ATC for a pilot to conduct an instrument approach. The type
of instrument approach for which a clearance and other pertinent information is provided in the approach
clearance when required.
(See CLEARED APPROACH.)
(See INSTRUMENT APPROACH PROCEDURE.)
(Refer to AIM.)
(Refer to 14 CFR part 91.)
APPROACH CONTROL FACILITY− A terminal ATC facility that provides approach control service in a
terminal area.
(See APPROACH CONTROL SERVICE.)
(See RADAR APPROACH CONTROL FACILITY.)
APPROACH CONTROL SERVICE− Air traffic control service provided by an approach control facility for
arriving and departing VFR/IFR aircraft and, on occasion, en route aircraft. At some airports not served by an
approach control facility, the ARTCC provides limited approach control service.
(See ICAO term APPROACH CONTROL SERVICE.)
(Refer to AIM.)
APPROACH CONTROL SERVICE [ICAO]− Air traffic control service for arriving or departing controlled
flights.
APPROACH GA TE− An imaginary point used within ATC as a basis for vectoring aircraft to the final approach
course. The gate will be established along the final approach course 1 mile from the final approach fix on the
side away from the airport and will be no closer than 5 miles from the landing threshold.
APPROACH/DEPARTURE HOLD AREA− The locations on taxiways in the approach or departure areas of
a runway designated to protect landing or departing aircraft. These locations are identified by signs and
markings.
APPROACH LIGHT SYSTEM−
(See AIRPORT LIGHTING.)
APPROACH RUNWAY VERIFICATION− A STARS functionality that provides audible and visual alerts to
tower and/or TRACON controllers when an aircraft is on its final approach course but not aligned with its
assigned landing runway, or if the runway is closed.
APPROACH SEQUENCE− The order in which aircraft are positioned while on approach or awaiting approach
clearance.
(See LANDING SEQUENCE.)
(See ICAO term APPROACH SEQUENCE.)
Pilot/Controller Glossary 1/22/26
Pilot/Controller Glossary2/20/25
PCG A−15
APPROACH SEQUENCE [ICAO]− The order in which two or more aircraft are cleared to approach to land at
the aerodrome.
APPROACH SPEED− The recommended speed contained in aircraft manuals used by pilots when making an
approach to landing. This speed will vary for different segments of an approach as well as for aircraft weight
and configuration.
APPROACH WITH VERTICAL GUIDANCE (APV)– A term used to describe RNA V approach procedures that
provide lateral and vertical guidance but do not meet the requirements to be considered a precision approach.
APPROPRIATE ATS AUTHORITY [ICAO]− The relevant authority designated by the State responsible for
providing air traffic services in the airspace concerned. In the United States, the “appropriate ATS authority” is
the Program Director for Air Traffic Planning and Procedures, ATP-1.
APPROPRIATE AUTHORITY−
a. Regarding flight over the high seas: the relevant authority is the State of Registry.
b. Regarding flight over other than the high seas: the relevant authority is the State having sovereignty over
the territory being overflown.
APPROPRIATE OBSTACLE CLEARANCE MINIMUM ALTITUDE− Any of the following:
(See MINIMUM EN ROUTE IFR ALTITUDE.)
(See MINIMUM IFR ALTITUDE.)
(See MINIMUM OBSTRUCTION CLEARANCE ALTITUDE.)
(See MINIMUM VECTORING ALTITUDE.)
APPROPRIATE TERRAIN CLEARANCE MINIMUM AL TITUDE− Any of the following:
(See MINIMUM EN ROUTE IFR ALTITUDE.)
(See MINIMUM IFR ALTITUDE.)
(See MINIMUM OBSTRUCTION CLEARANCE ALTITUDE.)
(See MINIMUM VECTORING ALTITUDE.)
APRON− A defined area on an airport or heliport intended to accommodate aircraft for purposes of loading or
unloading passengers or cargo, refueling, parking, or maintenance. With regard to seaplanes, a ramp is used for
access to the apron from the water.
(See ICAO term APRON.)
APRON [ICAO]− A defined area, on a land aerodrome, intended to accommodate aircraft for purposes of loading
or unloading passengers, mail or cargo, refueling, parking or maintenance.
ARC− The track over the ground of an aircraft flying at a constant distance from a navigational aid by reference
to distance measuring equipment (DME).
AREA CONTROL CENTER [ICAO]− An air traffic control facility primarily responsible for ATC services
being provided IFR aircraft during the en route phase of flight. The U.S. equivalent facility is an air route traffic
control center (ARTCC).
AREA NA VIGATION (RNA V)− A method of navigation which permits aircraft operation on any desired flight
path within the coverage of ground− or space−based navigation aids or within the limits of the capability of
self-contained aids, or a combination of these.
Note: Area navigation includes performance−based navigation as well as other operations that do not meet
the definition of performance−based navigation.
AREA NA VIGA TION (RNA V) APPROACH CONFIGURATION:
a. STANDARD T− An RNA V approach whose design allows direct flight to any one of three initial approach
fixes (IAF) and eliminates the need for procedure turns. The standard design is to align the procedure on the
extended centerline with the missed approach point (MAP) at the runway threshold, the final approach fix (FAF),
and the initial approach/intermediate fix (IAF/IF). The other two IAFs will be established perpendicular to the
IF.
1/22/26 Pilot/Controller Glossary
Pilot/Controller Glossary 2/20/25
PCG A−16
b. MODIFIED T− An RNA V approach design for single or multiple runways where terrain or operational
constraints do not allow for the standard T. The “T” may be modified by increasing or decreasing the angle from
the corner IAF(s) to the IF or by eliminating one or both corner IAFs.
c. STANDARD I− An RNA V approach design for a single runway with both corner IAFs eliminated. Course
reversal or radar vectoring may be required at busy terminals with multiple runways.
d. TERMINAL ARRIV AL AREA (TAA)− The TAA is controlled airspace established in conjunction with
the Standard or Modified T and I RNA V approach configurations. In the standard TAA, there are three areas:
straight-in, left base, and right base. The arc boundaries of the three areas of the TAA are published portions of
the approach and allow aircraft to transition from the en route structure direct to the nearest IAF. TAAs will also
eliminate or reduce feeder routes, departure extensions, and procedure turns or course reversal.
1. STRAIGHT-IN AREA− A 30 NM arc centered on the IF bounded by a straight line extending through
the IF perpendicular to the intermediate course.
2. LEFT BASE AREA− A 30 NM arc centered on the right corner IAF. The area shares a boundary with
the straight-in area except that it extends out for 30 NM from the IAF and is bounded on the other side by a line
extending from the IF through the FAF to the arc.
3. RIGHT BASE AREA− A 30 NM arc centered on the left corner IAF. The area shares a boundary with
the straight-in area except that it extends out for 30 NM from the IAF and is bounded on the other side by a line
extending from the IF through the FAF to the arc.
AREA NAVIGATION (RNAV) GLOBAL POSITIONING SYSTEM (GPS) PRECISION RUNWAY
MONITORING (PRM) APPROACH–
A GPS approach, which requires vertical guidance, used in lieu of another type of PRM approach to conduct
approaches to parallel runways whose extended centerlines are separated by less than 4,300 feet and at least 3,000
feet, where simultaneous close parallel approaches are permitted. Also used in lieu of an ILS PRM and/or LDA
PRM approach to conduct Simultaneous Offset Instrument Approach (SOIA) operations.
ARMY A VIA TION FLIGHT INFORMATION BULLETIN− A bulletin that provides air operation data
covering Army, National Guard, and Army Reserve aviation activities.
ARO−
(See AIRPORT RESERVATION OFFICE.)
ARRESTING SYSTEM− A safety device consisting of two major components, namely, engaging or catching
devices and energy absorption devices for the purpose of arresting both tailhook and/or nontailhook-equipped
aircraft. It is used to prevent aircraft from overrunning runways when the aircraft cannot be stopped after landing
or during aborted takeoff. Arresting systems have various names; e.g., arresting gear, hook device, wire barrier
cable.
(See ABORT.)
(Refer to AIM.)
ARRIV AL CENTER− The ARTCC having jurisdiction for the impacted airport.
ARRIV AL DELAY− A parameter which specifies a period of time in which no aircraft will be metered for arrival
at the specified airport.
ARRIV AL/DEPARTURE WINDOW (ADW)− A depiction presented on an air traffic control display, used by
the controller to prevent possible conflicts between arrivals to, and departures from, a runway. The ADW
identifies that point on the final approach course by which a departing aircraft must have begun takeoff.
ARRIV AL SECTOR (En Route)− An operational control sector containing one or more meter fixes on or near
the TRACON boundary.
ARRIV AL TIME− The time an aircraft touches down on arrival.
ARSR−
(See AIR ROUTE SURVEILLANCE RADAR.)
Pilot/Controller Glossary 1/22/26
Pilot/Controller Glossary2/20/25
PCG A−17
ARTCC−
(See AIR ROUTE TRAFFIC CONTROL CENTER.)
ASDA−
(See ACCELERATE-STOP DISTANCE AVAILABLE.)
ASDA [ICAO]−
(See ICAO Term ACCELERATE-STOP DISTANCE AVAILABLE.)
ASDE−
(See AIRPORT SURFACE DETECTION EQUIPMENT.)
ASLAR−
(See AIRCRAFT SURGE LAUNCH AND RECOVERY.)
ASR−
(See AIRPORT SURVEILLANCE RADAR.)
ASR APPROACH−
(See SURVEILLANCE APPROACH.)
ASSOCIATED− A radar target displaying a data block with flight identification and altitude information.
(See UNASSOCIATED.)
ATC−
(See AIR TRAFFIC CONTROL.)
ATC ADVISES− Used to prefix a message of noncontrol information when it is relayed to an aircraft by other
than an air traffic controller.
(See ADVISORY.)
ATC ASSIGNED AIRSPACE− Airspace of defined vertical/lateral limits, assigned by ATC, for the purpose of
providing air traffic segregation between the specified activities being conducted within the assigned airspace
and other IFR air traffic.
(See SPECIAL USE AIRSPACE.)
ATC CLEARANCE−
(See AIR TRAFFIC CLEARANCE.)
ATC CLEARS− Used to prefix an ATC clearance when it is relayed to an aircraft by other than an air traffic
controller.
ATC INSTRUCTIONS− Directives issued by air traffic control for the purpose of requiring a pilot to take
specific actions; e.g., “Turn left heading two five zero,” “Go around,” “Clear the runway.”
(Refer to 14 CFR part 91.)
ATC PREFERRED ROUTE NOTIFICATION− EDST notification to the appropriate controller of the need to
determine if an ATC preferred route needs to be applied, based on destination airport.
(See ROUTE ACTION NOTIFICATION.)
(See EN ROUTE DECISION SUPPORT TOOL.)
ATC PREFERRED ROUTES− Preferred routes that are not automatically applied by Host.
ATC REQUESTS− Used to prefix an ATC request when it is relayed to an aircraft by other than an air traffic
controller.
ATC SECURITY SERVICES− Communications and security tracking provided by an ATC facility in support
of the DHS, the DoD, or other Federal security elements in the interest of national security. Such security services
are only applicable within designated areas. ATC security services do not include ATC basic radar services or
flight following.
1/22/26 Pilot/Controller Glossary
Pilot/Controller Glossary 2/20/25
PCG A−18
ATC SECURITY SERVICES POSITION− The position responsible for providing ATC security services as
defined. This position does not provide ATC, IFR separation, or VFR flight following services, but is responsible
for providing security services in an area comprising airspace assigned to one or more ATC operating sectors.
This position may be combined with control positions.
ATC SECURITY TRACKING− The continuous tracking of aircraft movement by an ATC facility in support
of the DHS, the DoD, or other security elements for national security using radar (i.e., radar tracking) or other
means (e.g., manual tracking) without providing basic radar services (including traffic advisories) or other ATC
services not defined in this section.
ATS SURVEILLANCE SERVICE [ICAO]– A term used to indicate a service provided directly by means of an
ATS surveillance system.
ATC SURVEILLANCE SOURCE– Used by ATC for establishing identification, control and separation using
a target depicted on an air traffic control facility’s video display that has met the relevant safety standards for
operational use and received from one, or a combination, of the following surveillance sources:
a. Radar (See RADAR.)
b. ADS-B (See AUTOMATIC DEPENDENT SURVEILLANCE−BROADCAST.)
c. WAM (See WIDE AREA MULTILATERATION.)
(See INTERROGATOR.)
(See TRANSPONDER.)
(See ICAO term RADAR.)
(Refer to AIM.)
ATS SURVEILLANCE SYSTEM [ICAO]– A generic term meaning variously, ADS −B, PSR, SSR or any
comparable ground−based system that enables the identification of aircraft.
Note: A comparable ground−based system is one that has been demonstrated, by comparative assessment
or other methodology, to have a level of safety and performance equal to or better than monopulse SSR.
ATCAA−
(See ATC ASSIGNED AIRSPACE.)
ATCRBS−
(See RADAR.)
ATCSCC−
(See AIR TRAFFIC CONTROL SYSTEM COMMAND CENTER.)
ATCT−
(See TOWER.)
ATD−
(See ALONG−TRACK DISTANCE.)
ATIS−
(See AUTOMATIC TERMINAL INFORMATION SERVICE.)
ATIS [ICAO]−
(See ICAO Term AUTOMATIC TERMINAL INFORMATION SERVICE.)
ATO−
(See AIR TRAFFIC ORGANIZATION.)
ATPA−
(See AUTOMATED TERMINAL PROXIMITY ALERT.)
ATS ROUTE [ICAO]− A specified route designed for channeling the flow of traffic as necessary for the provision
of air traffic services.
Note: The term “ATS Route” is used to mean variously, airway, advisory route, controlled or uncontrolled route,
arrival or departure, etc.
Pilot/Controller Glossary 1/22/26
Pilot/Controller Glossary2/20/25
PCG A−19
ATTENTION ALL USERS PAGE (AAUP)- The AAUP provides the pilot with additional information relative
to conducting a specific operation, for example, PRM approaches and RNA V departures.
AUTOLAND APPROACH−An autoland system aids by providing control of aircraft systems during a precision
instrument approach to at least decision altitude and possibly all the way to touchdown, as well as in some cases,
through the landing rollout. The autoland system is a sub-system of the autopilot system from which control
surface management occurs. The aircraft autopilot sends instructions to the autoland system and monitors the
autoland system performance and integrity during its execution.
AUTOMATED EMERGENCY DESCENT−
(See EMERGENCY DESCENT MODE.)
AUTOMATED INFORMATION TRANSFER (AIT)− A precoordinated process, specifically defined in facility
directives, during which a transfer of altitude control and/or radar identification is accomplished without verbal
coordination between controllers using information communicated in a full data block.
AUTOMATED MUTUAL-ASSISTANCE VESSEL RESCUE SYSTEM− A facility which can deliver, in a
matter of minutes, a surface picture (SURPIC) of vessels in the area of a potential or actual search and rescue
incident, including their predicted positions and their characteristics.
(See FAA Order JO 7110.65, Para 10−6−4, INFLIGHT CONTINGENCIES.)
AUTOMATED PROBLEM DETECTION (APD) − An Automation Processing capability that compares
trajectories in order to predict conflicts.
AUTOMATED PROBLEM DETECTION BOUNDARY (APB) − The adapted distance beyond a facilities
boundary defining the airspace within which EDST performs conflict detection.
(See EN ROUTE DECISION SUPPORT TOOL.)
AUTOMATED PROBLEM DETECTION INHIBITED AREA (APDIA)− Airspace surrounding a terminal area
within which APD is inhibited for all flights within that airspace.
AUTOMATED SERVICES–Services delivered via an automated system (that is, without human interaction).
For example, flight plans, Notices to Airmen (NOTAMs), interactive maps, computer-generated text-to-speech
messages, short message service, or email.
AUTOMATED TERMINAL PROXIMITY ALERT (ATPA)− Monitors the separation of aircraft on the Final
Approach Course (FAC), displaying a graphical notification (cone and/or mileage) when a potential loss of
separation is detected. The warning cone (Yellow) will display at 45 seconds and the alert cone (Red) will display
at 24 seconds prior to predicted loss of separation. Current distance between two aircraft on final will be
displayed in line 3 of the full data block of the trailing aircraft in corresponding colors.
AUTOMATED WEA THER SYSTEM− Any of the automated weather sensor platforms that collect weather data
at airports and disseminate the weather information via radio and/or landline. The systems currently consist of
the Automated Surface Observing System (ASOS) and Automated Weather Observation System (AWOS).
AUTOMATED UNICOM− Provides completely automated weather, radio check capability and airport advisory
information on an Automated UNICOM system. These systems offer a variety of features, typically selectable
by microphone clicks, on the UNICOM frequency. Availability will be published in the Chart Supplement and
approach charts.
AUTOMATIC ALTITUDE REPORT−
(See ALTITUDE READOUT.)
AUTOMATIC ALTITUDE REPORTING − That function of a transponder which responds to Mode C
interrogations by transmitting the aircraft’s altitude in 100-foot increments.
AUTOMATIC CARRIER LANDING SYSTEM− U.S. Navy final approach equipment consisting of precision
tracking radar coupled to a computer data link to provide continuous information to the aircraft, monitoring
capability to the pilot, and a backup approach system.
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PCG A−20
AUTOMATIC DEPENDENT SURVEILLANCE (ADS) [ICAO]− A surveillance technique in which aircraft
automatically provide, via a data link, data derived from on −board navigation and position fixing systems,
including aircraft identification, four dimensional position and additional data as appropriate.
AUTOMATIC DEPENDENT SURVEILLANCE−BROADCAST (ADS-B)− A surveillance system in which
an aircraft or vehicle to be detected is fitted with cooperative equipment in the form of a data link transmitter.
The aircraft or vehicle periodically broadcasts its GNSS−derived position and other required information such
as identity and velocity, which is then received by a ground−based or space−based receiver for processing and
display at an air traffic control facility, as well as by suitably equipped aircraft.
(See AUTOMATIC DEPENDENT SURVEILLANCE−BROADCAST IN.)
(See AUTOMATIC DEPENDENT SURVEILLANCE−BROADCAST OUT.)
(See COOPERATIVE SURVEILLANCE.)
(See GLOBAL POSITIONING SYSTEM.)
(See SPACE−BASED ADS−B.)
AUTOMATIC DEPENDENT SURVEILLANCE−BROADCAST IN (ADS−B In)− Aircraft avionics capable
of receiving ADS−B Out transmissions directly from other aircraft, as well as traffic or weather information
transmitted from ground stations.
(See AUTOMATIC DEPENDENT SURVEILLANCE−BROADCAST OUT.)
(See AUTOMATIC DEPENDENT SURVEILLANCE−REBROADCAST.)
(See FLIGHT INFORMATION SERVICE−BROADCAST.)
(See TRAFFIC INFORMATION SERVICE−BROADCAST.)
AUTOMATIC DEPENDENT SURVEILLANCE −BROADCAST OUT (ADS −B Out)− The transmitter
onboard an aircraft or ground vehicle that periodically broadcasts its GNSS−derived position along with other
required information, such as identity, altitude, and velocity.
(See AUTOMATIC DEPENDENT SURVEILLANCE−BROADCAST.)
(See AUTOMATIC DEPENDENT SURVEILLANCE−BROADCAST IN.)
AUTOMATIC DEPENDENT SURVEILLANCE−CONTRACT (ADS−C)− A data link position reporting
system, controlled by a ground station, that establishes contracts with an aircraft’s avionics that occur
automatically whenever specific events occur, or specific time intervals are reached.
AUTOMATIC DEPENDENT SURVEILLANCE- REBROADCAST (ADS-R)− A datalink translation function
of the ADS−B ground system required to accommodate the two separate operating frequencies (978 MHz and
1090 MHz). The ADS−B system receives the ADS −B messages transmitted on one frequency and ADS −R
translates and reformats the information for rebroadcast and use on the other frequency. This allows ADS−B In
equipped aircraft to see nearby ADS−B Out traffic regardless of the operating link of the other aircraft. Aircraft
operating on the same ADS −B frequency exchange information directly and do not require the ADS −R
translation function.
AUTOMATIC DIRECTION FINDER− An aircraft radio navigation system which senses and indicates the
direction to a L/MF nondirectional radio beacon (NDB) ground transmitter. Direction is indicated to the pilot
as a magnetic bearing or as a relative bearing to the longitudinal axis of the aircraft depending on the type of
indicator installed in the aircraft. In certain applications, such as military, ADF operations may be based on
airborne and ground transmitters in the VHF/UHF frequency spectrum.
(See BEARING.)
(See NONDIRECTIONAL BEACON.)
AUTOMATIC FLIGHT INFORMATION SERVICE (AFIS) − ALASKA FSSs ONLY − The continuous
broadcast of recorded non−control information at airports in Alaska where a FSS provides local airport advisory
service. The AFIS broadcast automates the repetitive transmission of essential but routine information such as
weather, wind, altimeter, favored runway, braking action, airport NOTAMs, and other applicable information.
The information is continuously broadcast over a discrete VHF radio frequency (usually the ASOS/AWOS
frequency).
Pilot/Controller Glossary 1/22/26
Pilot/Controller Glossary2/20/25
PCG A−21
AUTOMATIC TERMINAL INFORMATION SERVICE− The continuous broadcast of recorded noncontrol
information in selected terminal areas. Its purpose is to improve controller effectiveness and to relieve frequency
congestion by automating the repetitive transmission of essential but routine information; e.g., “Los Angeles
information Alfa. One three zero zero Coordinated Universal Time. Weather, measured ceiling two thousand
overcast, visibility three, haze, smoke, temperature seven one, dew point five seven, wind two five zero at five,
altimeter two niner niner six. I-L-S Runway Two Five Left approach in use, Runway Two Five Right closed,
advise you have Alfa.”
(See ICAO term AUTOMATIC TERMINAL INFORMATION SERVICE.)
(Refer to AIM.)
AUTOMATIC TERMINAL INFORMATION SERVICE [ICAO] − The provision of current, routine
information to arriving and departing aircraft by means of continuous and repetitive broadcasts throughout the
day or a specified portion of the day.
AUTOROTATION− A rotorcraft flight condition in which the lifting rotor is driven entirely by action of the air
when the rotorcraft is in motion.
a. Autorotative Landing/Touchdown Autorotation. Used by a pilot to indicate that the landing will be made
without applying power to the rotor.
b. Low Level Autorotation. Commences at an altitude well below the traffic pattern, usually below 100 feet
AGL and is used primarily for tactical military training.
c. 180 degrees Autorotation. Initiated from a downwind heading and is commenced well inside the normal
traffic pattern. “Go around” may not be possible during the latter part of this maneuver.
A V AILABLE LANDING DISTANCE (ALD)− The portion of a runway available for landing and roll-out for
aircraft cleared for LAHSO. This distance is measured from the landing threshold to the hold-short point.
A VIA TION W ATCH NOTIFICATION MESSAGE− The Storm Prediction Center (SPC) issues Aviation Watch
Notification Messages (SAW) to provide an area threat alert for the aviation meteorology community to forecast
organized severe thunderstorms that may produce tornadoes, large hail, and/or convective damaging winds as
indicated in Public Watch Notification Messages within the Continental U.S. A SAW message provides a
description of the type of watch issued by SPC, a valid time, an approximation of the area in a watch, and primary
hazard(s).
AVIATION WEATHER SERVICE− A service provided by the National Weather Service (NWS) and FAA which
collects and disseminates pertinent weather information for pilots, aircraft operators, and ATC. Available
aviation weather reports and forecasts are displayed at each NWS office and FAA FSS.
(See TRANSCRIBED WEATHER BROADCAST.)
(See WEATHER ADVISORY.)
(Refer to AIM.)
1/22/26 Pilot/Controller Glossary
Pilot/Controller Glossary2/20/25
PCG B−1
B4UFLY− A free downloadable application, which allows operators to check airspace and local advisories
before flying.
BACK-TAXI− A term used by air traffic controllers to taxi an aircraft on the runway opposite to the traffic flow.
The aircraft may be instructed to back-taxi to the beginning of the runway or at some point before reaching the
runway end for the purpose of departure or to exit the runway.
BASE LEG−
(See TRAFFIC PATTERN.)
BEACON−
(See AERONAUTICAL BEACON.)
(See AIRPORT ROTATING BEACON.)
(See AIRWAY BEACON.)
(See MARKER BEACON.)
(See NONDIRECTIONAL BEACON.)
(See RADAR.)
BEARING− The horizontal direction to or from any point, usually measured clockwise from true north,
magnetic north, or some other reference point through 360 degrees.
(See NONDIRECTIONAL BEACON.)
BELOW MINIMUMS− Weather conditions below the minimums prescribed by regulation for the particular
action involved; e.g., landing minimums, takeoff minimums.
BEYOND VISUAL LINE OF SIGHT (BVLOS)− The operation of a UAS beyond the visual capability of the
flight crew members (i.e., remote pilot in command [RPIC], the person manipulating the controls, and visual
observer [VO]), if used to see the aircraft with vision unaided by any device other than corrective lenses,
spectacles, and contact lenses.
BLAST FENCE− A barrier that is used to divert or dissipate jet or propeller blast.
BLAST PAD− A surface adjacent to the ends of a runway provided to reduce the erosive effect of jet blast and
propeller wash.
BLIND SPEED− The rate of departure or closing of a target relative to the radar antenna at which cancellation
of the primary radar target by moving target indicator (MTI) circuits in the radar equipment causes a reduction
or complete loss of signal.
(See ICAO term BLIND VELOCITY.)
BLIND SPOT− An area from which radio transmissions and/or radar echoes cannot be received. The term is also
used to describe portions of the airport not visible from the control tower.
BLIND TRANSMISSION−
(See TRANSMITTING IN THE BLIND.)
BLIND VELOCITY [ICAO]− The radial velocity of a moving target such that the target is not seen on primary
radars fitted with certain forms of fixed echo suppression.
BLIND ZONE−
(See BLIND SPOT.)
BLOCKED− Phraseology used to indicate that a radio transmission has been distorted or interrupted due to
multiple simultaneous radio transmissions.
BOTTOM ALTITUDE– In reference to published altitude restrictions on a STAR or STAR runway transition,
the lowest altitude authorized.
Pilot/Controller Glossary 2/20/25
PCG B−2
BOUNDARY LIGHTS−
(See AIRPORT LIGHTING.)
BRAKING ACTION (GOOD, GOOD TO MEDIUM, MEDIUM, MEDIUM TO POOR, POOR, OR NIL)− A
report of conditions on the airport movement area providing a pilot with a degree/quality of braking to expect.
Braking action is reported in terms of good, good to medium, medium, medium to poor, poor, or nil.
(See RUNWAY CONDITION READING.)
(See RUNWAY CONDITION REPORT.)
(See RUNWAY CONDITION CODES.)
BRAKING ACTION ADVISORIES− When tower controllers receive runway braking action reports which
include the terms “medium,” “poor,” or “nil,” or whenever weather conditions are conducive to deteriorating
or rapidly changing runway braking conditions, the tower will include on the ATIS broadcast the statement,
“Braking Action Advisories are in Effect.” During the time braking action advisories are in effect, ATC will issue
the most current braking action report for the runway in use to each arriving and departing aircraft. Pilots should
be prepared for deteriorating braking conditions and should request current runway condition information if not
issued by controllers. Pilots should also be prepared to provide a descriptive runway condition report to
controllers after landing.
BREAKOUT− A technique to direct aircraft out of the approach stream. In the context of simultaneous
(independent) parallel operations, a breakout is used to direct threatened aircraft away from a deviating aircraft.
BROADCAST− Transmission of information for which an acknowledgement is not expected.
(See ICAO term BROADCAST.)
BROADCAST [ICAO]− A transmission of information relating to air navigation that is not addressed to a
specific station or stations.
BUFFER AREA− As applied to an MV A or MIA chart, a depicted 3 NM or 5 NM radius MV A/MIA sector
isolating a displayed obstacle for which the sector is established. A portion of a buffer area can also be inclusive
of a MV A/MIA sector polygon boundary.
BVLOS−
(See BEYOND VISUAL LINE OF SIGHT.)
Pilot/Controller Glossary2/20/25
PCG C−1
CALCULATED LANDING TIME− A term that may be used in place of tentative or actual calculated landing
time, whichever applies.
CALIBRATED AIRSPEED (CAS) – The indicated airspeed of an aircraft, corrected for position and instrument
error. Calibrated airspeed is equal to true airspeed in standard atmosphere at sea level.
CALL FOR RELEASE − Wherein the overlying ARTCC requires a terminal facility to initiate verbal
coordination to secure ARTCC approval for release of a departure into the en route environment.
CALL UP− Initial voice contact between a facility and an aircraft, using the identification of the unit being called
and the unit initiating the call.
(Refer to AIM.)
CANADIAN MINIMUM NA VIGA TION PERFORMANCE SPECIFICATION AIRSPACE− That portion of
Canadian domestic airspace within which MNPS separation may be applied.
CARDINAL ALTITUDES− “Odd” or “Even” thousand-foot altitudes or flight levels; e.g., 5,000, 6,000, 7,000,
FL 250, FL 260, FL 270.
(See ALTITUDE.)
(See FLIGHT LEVEL.)
CARDINAL FLIGHT LEVELS−
(See CARDINAL ALTITUDES.)
CAT−
(See CLEAR-AIR TURBULENCE.)
CATCH POINT− A fix/waypoint that serves as a transition point from the high altitude waypoint navigation
structure to an arrival procedure (STAR) or the low altitude ground−based navigation structure.
CBO−
(See COMMUNITY−BASED ORGANIZATION.)
CCF−
(See COMBINED CONTROL FACILITY.)
CEILING− The heights above the earth’s surface of the lowest layer of clouds or obscuring phenomena that is
reported as “broken,” “overcast,” or “obscuration,” and not classified as “thin” or “partial.”
(See ICAO term CEILING.)
CEILING [ICAO]− The height above the ground or water of the base of the lowest layer of cloud below 6,000
meters (20,000 feet) covering more than half the sky.
CENTER−
(See AIR ROUTE TRAFFIC CONTROL CENTER.)
CENTER’S AREA− The specified airspace within which an air route traffic control center (ARTCC) provides
air traffic control and advisory service.
(See AIR ROUTE TRAFFIC CONTROL CENTER.)
(Refer to AIM.)
7/9/26 Pilot/Controller Glossary
Pilot/Controller Glossary 2/20/25
PCG C−2
CENTER WEATHER ADVISORY− An unscheduled weather advisory issued by Center Weather Service Unit
meteorologists for ATC use to alert pilots of existing or anticipated adverse weather conditions within the next
2 hours. A CWA may modify or redefine a SIGMET.
(See AIRMET.)
(See CONVECTIVE SIGMET.)
(See GRAPHICAL AIRMEN’S METEOROLOGICAL INFORMATION.)
(See SAW.)
(See SIGMET.)
(Refer to AIM.)
CENTRAL EAST PACIFIC− An organized route system between the U.S. West Coast and Hawaii.
CEP−
(See CENTRAL EAST PACIFIC.)
CERTIFICATE OF WAIVER OR AUTHORIZATION (COA)− An FAA grant of approval for a specific flight
operation or airspace authorization or waiver.
CERTIFIED TOWER RADAR DISPLAY (CTRD)− An FAA radar display certified for use in the NAS.
CFR−
(See CALL FOR RELEASE.)
CHA
(See CONTINGENCY HAZARD AREA)
CHAFF− Thin, narrow metallic reflectors of various lengths and frequency responses, used to reflect radar
energy. These reflectors, when dropped from aircraft and allowed to drift downward, result in large targets on
the radar display.
CHART SUPPLEMENT− A series of civil/military flight information publications issued by FAA every 56 days
consisting of the Chart Supplement U.S., Chart Supplement Alaska, and Chart Supplement Pacific.
CHART SUPPLEMENT ALASKA− A flight information publication designed for use with appropriate IFR
or VFR charts which contains data on all airports, seaplane bases, and heliports open to the public including
communications data, navigational facilities, airport diagrams, certain special notices, and non −regulatory
procedures. Also included in this publication are selected entries needed to support the unique geographical
operational conditions of Alaska. This publication is issued in one volume for the state of Alaska.
CHART SUPPLEMENT PACIFIC− A flight information publication designed for use with appropriate IFR or
VFR charts which contains data on all airports, seaplane bases, and heliports open to the public including
communications data, navigational facilities, airport diagrams, certain special notices, and non −regulatory
procedures. Also included in this publication are Instrument Approach Procedures (IAP), Departure Procedures
(DP), and Standard Terminal Arrival (STAR) charts, along with selected entries needed to support the unique
geographical operational conditions of the Pacific Oceanic region. This publication is issued in one volume for
the Hawaiian Islands and other selected Pacific Islands.
CHART SUPPLEMENT U.S.− A flight information publication designed for use with appropriate IFR or VFR
charts which contains data on all airports, seaplane bases, and heliports open to the public including
communications data, navigational facilities, airport diagrams, certain special notices, and non −regulatory
procedures. This publication is issued for the conterminous U.S., Puerto Rico, and the Virgin Islands in seven
volumes according to geographical area.
CHARTED VFR FLYWAYS− Charted VFR Flyways are flight paths recommended for use to bypass areas
heavily traversed by large turbine-powered aircraft. Pilot compliance with recommended flyways and associated
altitudes is strictly voluntary. VFR Flyway Planning charts are published on the back of existing VFR Terminal
Area charts.
CHARTED VISUAL FLIGHT PROCEDURE APPROACH− An approach conducted while operating on an
instrument flight rules (IFR) flight plan which authorizes the pilot of an aircraft to proceed visually and clear
Pilot/Controller Glossary 7/9/26
Pilot/Controller Glossary2/20/25
PCG C−3
of clouds to the airport via visual landmarks and other information depicted on a charted visual flight procedure.
This approach must be authorized and under the control of the appropriate air traffic control facility. Weather
minimums required are depicted on the chart.
CHASE− An aircraft flown in proximity to another aircraft normally to observe its performance during training
or testing.
CHASE AIRCRAFT−
(See CHASE.)
CHOP− A form of turbulence.
a. Light Chop– Turbulence that causes slight, rapid and somewhat rhythmic bumpiness without appreciable
changes in altitude or attitude.
b. Moderate Chop– Turbulence similar to Light Chop but of greater intensity. It causes rapid bumps or jolts
without appreciable changes in aircraft altitude or attitude.
(See TURBULENCE.)
CIRCLE-TO-LAND MANEUVER− A maneuver initiated by the pilot to align the aircraft with a runway for
landing when a straight-in landing from an instrument approach is not possible or is not desirable. At tower
controlled airports, this maneuver is made only after ATC authorization has been obtained and the pilot has
established required visual reference to the airport.
(See CIRCLE TO RUNWAY.)
(See LANDING MINIMUMS.)
(Refer to AIM.)
CIRCLE TO RUNWAY (RUNWAY NUMBER)− Used by ATC to inform the pilot that he/she must circle to
land because the runway in use is other than the runway aligned with the instrument approach procedure. When
the direction of the circling maneuver in relation to the airport/runway is required, the controller will state the
direction (eight cardinal compass points) and specify a left or right downwind or base leg as appropriate; e.g.,
“Cleared VOR Runway Three Six Approach circle to Runway Two Two,” or “Circle northwest of the airport
for a right downwind to Runway Two Two.”
(See CIRCLE-TO-LAND MANEUVER.)
(See LANDING MINIMUMS.)
(Refer to AIM.)
CIRCLING APPROACH−
(See CIRCLE-TO-LAND MANEUVER.)
CIRCLING MANEUVER−
(See CIRCLE-TO-LAND MANEUVER.)
CIRCLING MINIMA−
(See CONTROLLED AIRSPACE.)
CIVIL AIRCRAFT OPERATION (CAO)− Aircraft operations other than public use.
CLASS A AIRSPACE−
(See CONTROLLED AIRSPACE.)
CLASS B AIRSPACE−
(See CONTROLLED AIRSPACE.)
CLASS C AIRSPACE−
(See CONTROLLED AIRSPACE.)
CLASS D AIRSPACE−
(See CONTROLLED AIRSPACE.)
CLASS E AIRSPACE−
(See CONTROLLED AIRSPACE.)
7/9/26 Pilot/Controller Glossary
Pilot/Controller Glossary 2/20/25
PCG C−4
CLASS G AIRSPACE− Airspace that is not designated in 14 CFR part 71 as Class A, Class B, Class C, Class
D, or Class E controlled airspace is Class G (uncontrolled) airspace.
(See UNCONTROLLED AIRSPACE.)
CLEAR AIR TURBULENCE (CAT)− Turbulence encountered in air where no clouds are present. This term is
commonly applied to high-level turbulence associated with wind shear. CAT is often encountered in the vicinity
of the jet stream.
(See WIND SHEAR.)
(See JET STREAM.)
CLEAR OF THE RUNWAY−
a. Taxiing aircraft, which is approaching a runway, is clear of the runway when all parts of the aircraft are held
short of the applicable runway holding position marking.
b. A pilot or controller may consider an aircraft, which is exiting or crossing a runway, to be clear of the
runway when all parts of the aircraft are beyond the runway edge and there are no restrictions to its continued
movement beyond the applicable runway holding position marking.
c. Pilots and controllers must exercise good judgment to ensure that adequate separation exists between all
aircraft on runways and taxiways at airports with inadequate runway edge lines or holding position markings.
CLEARANCE−
(See AIR TRAFFIC CLEARANCE.)
CLEARANCE LIMIT− The fix, point, or location to which an aircraft is cleared when issued an air traffic
clearance.
(See ICAO term CLEARANCE LIMIT.)
CLEARANCE LIMIT [ICAO]− The point to which an aircraft is granted an air traffic control clearance.
CLEARANCE VOID IF NOT OFF BY (TIME)− Used by ATC to advise an aircraft that the departure release
is automatically canceled if takeoff is not made prior to a specified time. The expiration of a clearance void time
does not cancel the departure clearance or IFR flight plan. It withdraws the pilot’s authority to depart IFR until
a new departure release/release time has been issued by ATC. Pilots who choose to depart VFR after their
clearance void time has expired should not depart using the previously assigned IFR transponder code.
(See ICAO term CLEARANCE VOID TIME.)
CLEARANCE VOID TIME [ICAO]− A time specified by an air traffic control unit at which a clearance ceases
to be valid unless the aircraft concerned has already taken action to comply therewith.
CLEARED APPROACH − ATC authorization for an aircraft to execute any standard or special instrument
approach procedure for that airport. Normally, an aircraft will be cleared for a specific instrument approach
procedure.
(See CLEARED (Type of) APPROACH.)
(See INSTRUMENT APPROACH PROCEDURE.)
(Refer to 14 CFR part 91.)
(Refer to AIM.)
CLEARED (Type of) APPROACH− ATC authorization for an aircraft to execute a specific instrument approach
procedure to an airport; e.g., “Cleared ILS Runway Three Six Approach.”
(See APPROACH CLEARANCE.)
(See INSTRUMENT APPROACH PROCEDURE.)
(Refer to 14 CFR part 91.)
(Refer to AIM.)
CLEARED AS FILED− Means the aircraft is cleared to proceed in accordance with the route of flight filed in
the flight plan. This clearance does not include the altitude, DP, or DP Transition.
(See REQUEST FULL ROUTE CLEARANCE.)
(Refer to AIM.)
Pilot/Controller Glossary 7/9/26
Pilot/Controller Glossary2/20/25
PCG C−5
CLEARED FOR TAKEOFF− ATC authorization for an aircraft to depart. It is predicated on known traffic and
known physical airport conditions.
CLEARED FOR THE OPTION − ATC authorization for an aircraft to make a touch-and-go, low approach,
missed approach, stop and go, or full stop landing at the discretion of the pilot. It is normally used in training
so that an instructor can evaluate a student’s performance under changing situations. Pilots should advise ATC
if they decide to remain on the runway, of any delay in their stop and go, delay clearing the runway, or are unable
to comply with the instruction(s).
(See OPTION APPROACH.)
(Refer to AIM.)
CLEARED THROUGH− ATC authorization for an aircraft to make intermediate stops at specified airports
without refiling a flight plan while en route to the clearance limit.
CLEARED TO LAND− ATC authorization for an aircraft to land. It is predicated on known traffic and known
physical airport conditions.
CLEARWAY− An area beyond the takeoff runway under the control of airport authorities within which terrain
or fixed obstacles may not extend above specified limits. These areas may be required for certain
turbine-powered operations and the size and upward slope of the clearway will differ depending on when the
aircraft was certificated.
(Refer to 14 CFR part 1.)
CLIMB TO VFR− ATC authorization for an aircraft to climb to VFR conditions within Class B, C, D, and E
surface areas when the only weather limitation is restricted visibility. The aircraft must remain clear of clouds
while climbing to VFR.
(See SPECIAL VFR CONDITIONS.)
(Refer to AIM.)
CLIMBOUT− That portion of flight operation between takeoff and the initial cruising altitude.
CLIMB VIA– An abbreviated ATC clearance that requires compliance with the procedure lateral path,
associated speed restrictions, and altitude restrictions along the cleared route or procedure.
CLOSE PARALLEL RUNWAYS− Two parallel runways whose extended centerlines are separated by less than
4,300 feet and at least 3000 feet (750 feet for SOIA operations) for which ATC is authorized to conduct
simultaneous independent approach operations. PRM and simultaneous close parallel appear in approach title.
Dual communications, special pilot training, an Attention All Users Page (AAUP), NTZ monitoring by displays
that have aural and visual alerting algorithms are required. A high update rate surveillance sensor is required for
certain runway or approach course spacing.
CLOSED LOOP CLEARANCE− A vector or reroute clearance that includes a return to route point and updates
ERAM to accurately reflect the anticipated route (e.g., a QU route pick that anticipates length of vector and
includes the next fix that ties into the route of flight.)
CLOSED RUNWAY− A runway that is unusable for aircraft operations. Only the airport management/military
operations office can close a runway.
CLOSED TRAFFIC− Successive operations involving takeoffs and landings or low approaches where the
aircraft does not exit the traffic pattern.
CLOUD− A cloud is a visible accumulation of minute water droplets and/or ice particles in the atmosphere above
the Earth’s surface. Cloud differs from ground fog, fog, or ice fog only in that the latter are, by definition, in
contact with the Earth’s surface.
CLT−
(See CALCULATED LANDING TIME.)
7/9/26 Pilot/Controller Glossary
Pilot/Controller Glossary 2/20/25
PCG C−6
CLUTTER− In radar operations, clutter refers to the reception and visual display of radar returns caused by
precipitation, chaff, terrain, numerous aircraft targets, or other phenomena. Such returns may limit or preclude
ATC from providing services based on radar.
(See CHAFF.)
(See GROUND CLUTTER.)
(See PRECIPITATION.)
(See TARGET.)
(See ICAO term RADAR CLUTTER.)
CMNPS−
(See CANADIAN MINIMUM NAVIGATION PERFORMANCE SPECIFICATION AIRSPACE.)
COA−
(See CERTIFICATE OF WAIVER OR AUTHORIZATION.)
COASTAL FIX− A navigation aid or intersection where an aircraft transitions between the domestic route
structure and the oceanic route structure.
CODES− The number assigned to a particular multiple pulse reply signal transmitted by a transponder.
(See DISCRETE CODE.)
COLD TEMPERATURE CORRECTION− A correction in feet, based on height above airport and temperature,
that is added to the aircraft’s indicated altitude to offset the effect of cold temperature on true altitude.
COLLABORATIVE TRAJECTORY OPTIONS PROGRAM (CTOP)− CTOP is a traffic management program
administered by the Air Traffic Control System Command Center (ATCSCC) that manages demand through
constrained airspace, while considering operator preference with regard to both route and delay as defined in a
Trajectory Options Set (TOS).
COMBINED CONTROL FACILITY (CCF)− An air traffic facility that combines the functions of an ARTCC
and a radar approach control facility.
(See AIR ROUTE TRAFFIC CONTROL CENTER.)
(See RADAR APPROACH CONTROL FACILITY.)
COMMON POINT− A significant point over which two or more aircraft will report passing or have reported
passing before proceeding on the same or diverging tracks. To establish/maintain longitudinal separation, a
controller may determine a common point not originally in the aircraft’s flight plan and then clear the aircraft
to fly over the point.
(See SIGNIFICANT POINT.)
COMMON PORTION−
(See COMMON ROUTE.)
COMMON ROUTE− That segment of a North American Route between the inland navigation facility and the
coastal fix.
OR
COMMON ROUTE−
(See SEGMENTS OF A SID/STAR)
COMMON TRAFFIC ADVISORY FREQUENCY (CTAF)− A frequency designed for the purpose of carrying
out airport advisory practices while operating to or from an airport without an operating control tower. The CTAF
may be a UNICOM, Multicom, FSS, or tower frequency and is identified in appropriate aeronautical
publications.
(See DESIGNATED COMMON TRAFFIC ADVISORY FREQUENCY (CTAF) AREA.)
(Refer to AC 90-66, Non−Towered Airport Flight Operations.)
Pilot/Controller Glossary 7/9/26
Pilot/Controller Glossary2/20/25
PCG C−7
COMMUNITY−BASED ORGANIZATION (CBO)− A membership−based entity, described under Section
501(a,c), whose mission is the furtherance of model aviation. (see also, 49 United States Code (USC) §44809
(h) and Advisory Circular (AC) 91−57).
COMPASS LOCATOR− A low power, low or medium frequency (L/MF) radio beacon installed at the site of
the outer or middle marker of an instrument landing system (ILS). It can be used for navigation at distances of
approximately 15 miles or as authorized in the approach procedure.
a. Outer Compass Locator (LOM)− A compass locator installed at the site of the outer marker of an instrument
landing system.
(See OUTER MARKER.)
b. Middle Compass Locator (LMM)− A compass locator installed at the site of the middle marker of an
instrument landing system.
(See MIDDLE MARKER.)
(See ICAO term LOCATOR.)
COMPASS ROSE− A circle, graduated in degrees, printed on some charts or marked on the ground at an airport.
It is used as a reference to either true or magnetic direction.
COMPLY WITH RESTRICTIONS− An A TC instruction that requires an aircraft being vectored back onto an
arrival or departure procedure to comply with all altitude and/or speed restrictions depicted on the procedure.
This term may be used in lieu of repeating each remaining restriction that appears on the procedure.
COMPOSITE FLIGHT PLAN− A flight plan which specifies VFR operation for one portion of flight and IFR
for another portion. It is used primarily in military operations.
(Refer to AIM.)
COMPULSORY REPORTING POINTS − Reporting points which must be reported to ATC. They are
designated on aeronautical charts by solid triangles or filed in a flight plan as fixes selected to define direct routes.
These points are geographical locations which are defined by navigation aids/fixes. Pilots should discontinue
position reporting over compulsory reporting points when informed by ATC that their aircraft is in “radar
contact.”
COMPUTER NA VIGATION FIX (CNF)− A Computer Navigation Fix is a point defined by a latitude/longitude
coordinate and is required to support Performance−Based Navigation (PBN) operations. A five−letter identifier
denoting a CNF can be found next to an “x” on en route charts and on some approach charts. Eventually, all CNFs
will be labeled and begin with the letters “CF” followed by three consonants (e.g., ‘CFWBG’). CNFs are not
recognized by A TC, are not contained in ATC fix or automation databases, and are not used for ATC purposes.
Pilots should not use CNFs for point −to−point navigation (e.g., proceed direct), filing a flight plan, or in
aircraft/A TC communications. Use of CNFs has not been adopted or recognized by the International Civil
Aviation Organization (ICAO).
(REFER to AIM 1−1−17b5(i)(2), Global Positioning System (GPS).
CONDITIONS NOT MONITORED− When an airport operator cannot monitor the condition of the movement
area or airfield surface area, this information is issued as a NOTAM. Usually necessitated due to staffing,
operating hours or other mitigating factors associated with airport operations.
CONFIDENCE MANEUVER− A confidence maneuver consists of one or more turns, a climb or descent, or
other maneuver to determine if the pilot in command (PIC) is able to receive and comply with ATC instructions.
CONFLICT ALERT− A function of certain air traffic control automated systems designed to alert radar
controllers to existing or pending situations between tracked targets (known IFR or VFR aircraft) that require
his/her immediate attention/action.
(See MODE C INTRUDER ALERT.)
CONFLICT RESOLUTION− The resolution of potential conflictions between aircraft that are radar identified
and in communication with ATC by ensuring that radar targets do not touch. Pertinent traffic advisories must
be issued when this procedure is applied.
Note: This procedure must not be provided utilizing mosaic radar systems.
Pilot/Controller Glossary 2/20/25
PCG C−8
CONFORMANCE− The condition established when an aircraft’s actual position is within the conformance
region constructed around that aircraft at its position, according to the trajectory associated with the aircraft’s
Current Plan.
CONFORMANCE REGION− A volume, bounded laterally, vertically, and longitudinally, within which an
aircraft must be at a given time in order to be in conformance with the Current Plan Trajectory for that aircraft.
At a given time, the conformance region is determined by the simultaneous application of the lateral, vertical,
and longitudinal conformance bounds for the aircraft at the position defined by time and aircraft’s trajectory.
CONNECTION− A virtual connection between the ground system and the aircraft for the exchange of CPDLC
messages.
CONSOLAN− A low frequency, long-distance NA V AID used principally for transoceanic navigations.
CONSTRAINT SATISFACTION POINT (CSP) − Meter Reference Elements (MREs) that are actively
scheduled by TBFM. Constraint satisfaction occurs when the Scheduled Time of Arrival generated for each
metered flight conforms to all the scheduling constraints specified at all the applicable CSPs.
CONTACT−
a. Establish communication with (followed by the name of the facility and, if appropriate, the frequency to
be used).
b. A flight condition wherein the pilot ascertains the attitude of his/her aircraft and navigates by visual
reference to the surface.
(See CONTACT APPROACH.)
(See RADAR CONTACT.)
CONTACT APPROACH− An approach wherein an aircraft on an IFR flight plan, having an air traffic control
authorization, operating clear of clouds with at least 1 mile flight visibility and a reasonable expectation of
continuing to the destination airport in those conditions, may deviate from the instrument approach procedure
and proceed to the destination airport by visual reference to the surface. This approach will only be authorized
when requested by the pilot and the reported ground visibility at the destination airport is at least 1 statute mile.
(Refer to AIM.)
CONTAMINATED RUNWAY− A runway is considered contaminated whenever standing water, ice, snow,
slush, frost in any form, heavy rubber, or other substances are present. A runway is contaminated with respect
to rubber deposits or other friction-degrading substances when the average friction value for any 500-foot
segment of the runway within the ALD fails below the recommended minimum friction level and the average
friction value in the adjacent 500-foot segments falls below the maintenance planning friction level.
CONTERMINOUS U.S.− The 48 adjoining States and the District of Columbia.
CONTINENTAL UNITED STATES− The 49 States located on the continent of North America and the District
of Columbia.
CONTINGENCY HAZARD AREA (CHA)− Used by ATC. Areas of airspace that are defined and distributed
in advance of a launch or reentry operation and are activated in response to a failure.
(See AIRCRAFT HAZARD AREA.)
(See REFINED HAZARD AREA.)
(See TRANSITIONAL HAZARD AREA.)
CONTINUE− When used as a control instruction should be followed by another word or words clarifying what
is expected of the pilot. Example: “continue taxi,” “continue descent,” “continue inbound,” etc.
CONTROL AREA [ICAO]− A controlled airspace extending upwards from a specified limit above the earth.
CONTROL SECTOR− An airspace area of defined horizontal and vertical dimensions for which a controller
or group of controllers has air traffic control responsibility, normally within an air route traffic control center
or an approach control facility. Sectors are established based on predominant traffic flows, altitude strata, and
Pilot/Controller Glossary 1/22/26
Pilot/Controller Glossary2/20/25
PCG C−9
controller workload. Pilot communications during operations within a sector are normally maintained on
discrete frequencies assigned to the sector.
(See DISCRETE FREQUENCY.)
CONTROL SLASH− A radar beacon slash representing the actual position of the associated aircraft. Normally,
the control slash is the one closest to the interrogating radar beacon site. When ARTCC radar is operating in
narrowband (digitized) mode, the control slash is converted to a target symbol.
CONTROLLED AIRSPACE− An airspace of defined dimensions within which air traffic control service is
provided to IFR flights and to VFR flights in accordance with the airspace classification.
a. Controlled airspace is a generic term that covers Class A, Class B, Class C, Class D, and Class E airspace.
b. Controlled airspace is also that airspace within which all aircraft operators are subject to certain pilot
qualifications, operating rules, and equipment requirements in 14 CFR part 91 (for specific operating
requirements, please refer to 14 CFR part 91). For IFR operations in any class of controlled airspace, a pilot must
file an IFR flight plan and receive an appropriate ATC clearance. Each Class B, Class C, and Class D airspace
area designated for an airport contains at least one primary airport around which the airspace is designated (for
specific designations and descriptions of the airspace classes, please refer to 14 CFR part 71).
c. Controlled airspace in the United States is designated as follows:
1. CLASS A− Generally, that airspace from 18,000 feet MSL up to and including FL 600, including the
airspace overlying the waters within 12 nautical miles of the coast of the 48 contiguous States and Alaska. Unless
otherwise authorized, all persons must operate their aircraft under IFR.
2. CLASS B− Generally, that airspace from the surface to 10,000 feet MSL surrounding the nation’s busiest
airports in terms of airport operations or passenger enplanements. The configuration of each Class B airspace
area is individually tailored and consists of a surface area and two or more layers (some Class B airspace areas
resemble upside-down wedding cakes), and is designed to contain all published instrument procedures once an
aircraft enters the airspace. An ATC clearance is required for all aircraft to operate in the area, and all aircraft
that are so cleared receive separation services within the airspace. The cloud clearance requirement for VFR
operations is “clear of clouds.”
3. CLASS C− Generally, that airspace from the surface to 4,000 feet above the airport elevation (charted
in MSL) surrounding those airports that have an operational control tower, are serviced by a radar approach
control, and that have a certain number of IFR operations or passenger enplanements. Although the configuration
of each Class C area is individually tailored, the airspace usually consists of a surface area with a 5 NM radius,
a circle with a 10 NM radius that extends no lower than 1,200 feet up to 4,000 feet above the airport elevation,
and an outer area that is not charted. Each person must establish two-way radio communications with the ATC
facility providing air traffic services prior to entering the airspace and thereafter maintain those communications
while within the airspace. VFR aircraft are only separated from IFR aircraft within the airspace.
(See OUTER AREA.)
4. CLASS D− Generally, that airspace from the surface to 2,500 feet above the airport elevation (charted
in MSL) surrounding those airports that have an operational control tower. The configuration of each Class D
airspace area is individually tailored and when instrument procedures are published, the airspace will normally
be designed to contain the procedures. Arrival extensions for instrument approach procedures may be Class D
or Class E airspace. Unless otherwise authorized, each person must establish two-way radio communications
with the ATC facility providing air traffic services prior to entering the airspace and thereafter maintain those
communications while in the airspace. No separation services are provided to VFR aircraft.
5. CLASS E− Generally, if the airspace is not Class A, Class B, Class C, or Class D, and it is controlled
airspace, it is Class E airspace. Class E airspace extends upward from either the surface or a designated altitude
to the overlying or adjacent controlled airspace. When designated as a surface area, the airspace will be
configured to contain all instrument procedures. Also in this class are Federal airways, airspace beginning at
either 700 or 1,200 feet AGL used to transition to/from the terminal or en route environment, en route domestic,
and offshore airspace areas designated below 18,000 feet MSL. Unless designated at a lower altitude, Class E
airspace begins at 14,500 MSL over the United States, including that airspace overlying the waters within 12
Pilot/Controller Glossary 2/20/25
PCG C−10
nautical miles of the coast of the 48 contiguous States and Alaska, up to, but not including 18,000 feet MSL,
and the airspace above FL 600.
CONTROLLED AIRSPACE [ICAO]− An airspace of defined dimensions within which air traffic control
service is provided to IFR flights and to VFR flights in accordance with the airspace classification.
Note: Controlled airspace is a generic term which covers ATS airspace Classes A, B, C, D, and E.
CONTROLLED TIME OF ARRIV AL− Arrival time assigned during a Traffic Management Program. This time
may be modified due to adjustments or user options.
CONTROLLER−
(See AIR TRAFFIC CONTROL SPECIALIST.)
CONTROLLER [ICAO]− A person authorized to provide air traffic control services.
CONTROLLER PILOT DATA LINK COMMUNICATIONS (CPDLC)− A two−way digital communications
system that conveys textual air traffic control messages between controllers and pilots using ground or
satellite-based radio relay stations.
CONVECTIVE SIGMET− A weather advisory concerning convective weather significant to the safety of all
aircraft. Convective SIGMETs are issued for tornadoes, lines of thunderstorms, embedded thunderstorms of any
intensity level, areas of thunderstorms greater than or equal to VIP level 4 with an area coverage of 4/10 (40%)
or more, and hail 3/4 inch or greater.
(See AIRMET.)
(See CWA.)
(See GRAPHICAL AIRMEN’S METEOROLOGICAL INFORMATION.)
(See SAW.)
(See SIGMET.)
(Refer to AIM.)
CONVECTIVE SIGNIFICANT METEOROLOGICAL INFORMATION−
(See CONVECTIVE SIGMET.)
COOPERATIVE SURVEILLANCE− Any surveillance system, such as secondary surveillance radar (SSR),
wide−area multilateration (WAM), or ADS−B, that is dependent upon the presence of certain equipment onboard
the aircraft or vehicle to be detected.
(See AUTOMATIC DEPENDENT SURVEILLANCE−BROADCAST.)
(See NON−COOPERATIVE SURVEILLANCE.)
(See RADAR.)
(See WIDE AREA MULTILATERATION.)
COORDINATES− The intersection of lines of reference, usually expressed in degrees/minutes/seconds of
latitude and longitude, used to determine position or location.
COORDINATION FIX− The fix in relation to which facilities will handoff, transfer control of an aircraft, or
coordinate flight progress data. For terminal facilities, it may also serve as a clearance for arriving aircraft.
COPTER−
(See HELICOPTER.)
CORRECTION− An error has been made in the transmission and the correct version follows.
COUPLED APPROACH− An instrument approach performed by the aircraft autopilot, and/or visually depicted
on the flight director, which is receiving position information and/or steering commands from onboard
navigational equipment. In general, coupled non-precision approaches must be flown manually (autopilot
disengaged) at altitudes lower than 50 feet AGL below the minimum descent altitude, and coupled precision
approaches must be flown manually (autopilot disengaged) below 50 feet AGL unless authorized to conduct
autoland operations. Coupled instrument approaches are commonly flown to the allowable IFR weather minima
established by the operator or PIC, or flown VFR for training and safety.
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PCG C−11
COUPLED SCHEDULING (CS)/ EXTENDED METERING (XM)− Adds additional Constraint Satisfaction
Points for metered aircraft along their route. This provides the ability to merge flows upstream from the meter
fix and results in a more optimal distribution of delays over a greater distance from the airport, increased meter
list accuracy, and more accurate delivery to the meter fix.
COURSE−
a. The intended direction of flight in the horizontal plane measured in degrees from north.
b. The ILS localizer signal pattern usually specified as the front course or the back course.
(See BEARING.)
(See INSTRUMENT LANDING SYSTEM.)
(See RADIAL.)
CPDLC−
(See CONTROLLER PILOT DATA LINK COMMUNICATIONS.)
CPL [ICAO]−
(See ICAO term CURRENT FLIGHT PLAN.)
CREWMEMBER (UAS)− A person assigned to perform an operational duty. A UAS crewmember includes the
remote pilot in command, the person manipulating the controls, and visual observers but may also include other
persons as appropriate or required to ensure the safe operation of the UAS (e.g., sensor operator, ground control
station operator).
CRITICAL ENGINE− The engine which, upon failure, would most adversely affect the performance or handling
qualities of an aircraft.
CROSS (FIX) AT (ALTITUDE)− Used by ATC when a specific altitude restriction at a specified fix is required.
CROSS (FIX) AT OR ABOVE (ALTITUDE)− Used by ATC when an altitude restriction at a specified fix is
required. It does not prohibit the aircraft from crossing the fix at a higher altitude than specified; however, the
higher altitude may not be one that will violate a succeeding altitude restriction or altitude assignment.
(See ALTITUDE RESTRICTION.)
(Refer to AIM.)
CROSS (FIX) AT OR BELOW (ALTITUDE)− Used by ATC when a maximum crossing altitude at a specific
fix is required. It does not prohibit the aircraft from crossing the fix at a lower altitude; however, it must be at
or above the minimum IFR altitude.
(See ALTITUDE RESTRICTION.)
(See MINIMUM IFR ALTITUDES.)
(Refer to 14 CFR part 91.)
CROSSWIND−
a. When used concerning the traffic pattern, the word means “crosswind leg.”
(See TRAFFIC PATTERN.)
b. When used concerning wind conditions, the word means a wind not parallel to the runway or the path of
an aircraft.
(See CROSSWIND COMPONENT.)
CROSSWIND COMPONENT− The wind component measured in knots at 90 degrees to the longitudinal axis
of the runway.
CRUISE− Used in an ATC clearance to authorize a pilot to conduct flight at any altitude from the minimum IFR
altitude up to and including the altitude specified in the clearance. The pilot may level off at any intermediate
altitude within this block of airspace. Climb/descent within the block is to be made at the discretion of the pilot.
However, once the pilot starts descent and verbally reports leaving an altitude in the block, he/she may not return
to that altitude without additional ATC clearance. Further, it is approval for the pilot to proceed to and make an
approach at destination airport and can be used in conjunction with:
Pilot/Controller Glossary 2/20/25
PCG C−12
a. An airport clearance limit at locations with a standard/special instrument approach procedure. The CFRs
require that if an instrument letdown to an airport is necessary, the pilot must make the letdown in accordance
with a standard/special instrument approach procedure for that airport, or
b. An airport clearance limit at locations that are within/below/outside controlled airspace and without a
standard/special instrument approach procedure. Such a clearance is NOT AUTHORIZATION for the pilot to
descend under IFR conditions below the applicable minimum IFR altitude nor does it imply that ATC is
exercising control over aircraft in Class G airspace; however, it provides a means for the aircraft to proceed to
destination airport, descend, and land in accordance with applicable CFRs governing VFR flight operations.
Also, this provides search and rescue protection until such time as the IFR flight plan is closed.
(See INSTRUMENT APPROACH PROCEDURE.)
CRUISE CLIMB− A climb technique employed by aircraft, usually at a constant power setting, resulting in an
increase of altitude as the aircraft weight decreases.
CRUISING ALTITUDE− An altitude or flight level maintained during en route level flight. This is a constant
altitude and should not be confused with a cruise clearance.
(See ALTITUDE.)
(See ICAO term CRUISING LEVEL.)
CRUISING LEVEL−
(See CRUISING ALTITUDE.)
CRUISING LEVEL [ICAO]− A level maintained during a significant portion of a flight.
CSP−
(See CONSTRAINT SATISFACTION POINT)
CT MESSAGE− An EDCT time generated by the ATCSCC to regulate traffic at arrival airports. Normally, a
CT message is automatically transferred from the traffic management system computer to the NAS en route
computer and appears as an EDCT. In the event of a communication failure between the traffic management
system computer and the NAS, the CT message can be manually entered by the TMC at the en route facility.
CTA−
(See CONTROLLED TIME OF ARRIVAL.)
(See ICAO term CONTROL AREA.)
CTAF−
(See COMMON TRAFFIC ADVISORY FREQUENCY.)
CTOP−
(See COLLABORATIVE TRAJECTORY OPTIONS PROGRAM)
CTRD−
(See CERTIFIED TOWER RADAR DISPLAY.)
CURRENT FLIGHT PLAN [ICAO]− The flight plan, including changes, if any, brought about by subsequent
clearances.
CVFP APPROACH−
(See CHARTED VISUAL FLIGHT PROCEDURE APPROACH.)
CWA−
(See CENTER WEATHER ADVISORY and WEATHER ADVISORY.)
CWT−
(See CONSOLIDATED WAKE TURBULENCE.)
Pilot/Controller Glossary2/20/25
PCG D−1
D−ATIS−
(See DIGITAL-AUTOMATIC TERMINAL INFORMATION SERVICE.)
D−A TIS [ICAO]−
(See ICAO Term DATA LINK AUTOMATIC TERMINAL INFORMATION SERVICE.)
DA [ICAO]−
(See ICAO Term DECISION ALTITUDE/DECISION HEIGHT.)
DAIR−
(See DIRECT ALTITUDE AND IDENTITY READOUT.)
DANGER AREA [ICAO]− An airspace of defined dimensions within which activities dangerous to the flight
of aircraft may exist at specified times.
Note: The term “Danger Area” is not used in reference to areas within the United States or any of its
possessions or territories.
DAS−
(See DELAY ASSIGNMENT.)
DATA BLOCK−
(See ALPHANUMERIC DISPLAY.)
DATA LINK AUTOMATIC TERMINAL INFORMATION SERVICE (D−ATIS) [ICAO]− The provision of
ATIS via data link.
DCL–
(See DEPARTURE CLEARANCE APPLICATION.)
DCT−
(See DELAY COUNTDOWN TIMER.)
DEAD RECKONING− Dead reckoning, as applied to flying, is the navigation of an airplane solely by means
of computations based on airspeed, course, heading, wind direction, and speed, groundspeed, and elapsed time.
DEBRIS RESPONSE AREA (DRA)− Used by ATC. Areas of airspace that may be activated in response to
unplanned falling debris in the NAS.
DECISION ALTITUDE/DECISION HEIGHT [ICAO Annex 6]- A specified altitude or height (A/H) in the
precision approach at which a missed approach must be initiated if the required visual reference to continue the
approach has not been established.
1. Decision altitude (DA) is referenced to mean sea level and decision height (DH) is referenced to the threshold
elevation.
2. Category II and III minima are expressed as a DH and not a DA. Minima is assessed by reference to a radio
altimeter and not a barometric altimeter, which makes the minima a DH.
3. The required visual reference means that section of the visual aids or of the approach area which should have
been in view for sufficient time for the pilot to have made an assessment of the aircraft position and rate of change
of position, in relation to the desired flight path.
DECISION ALTITUDE (DA) − A specified altitude (mean sea level (MSL)) on an instrument approach
procedure (ILS, GLS, vertically guided RNA V) at which the pilot must decide whether to continue the approach
or initiate an immediate missed approach if the pilot does not see the required visual references.
DECISION HEIGHT (DH)− With respect to the operation of aircraft, means the height at which a decision must
be made during an ILS or PAR instrument approach to either continue the approach or to execute a missed
approach.
(See ICAO term DECISION ALTITUDE/DECISION HEIGHT.)
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Pilot/Controller Glossary 2/20/25
PCG D−2
DECODER− The device used to decipher signals received from ATCRBS transponders to effect their display
as select codes.
(See CODES.)
(See RADAR.)
DEFENSE AREA– Any airspace of the contiguous United States that is not an ADIZ in which the control of
aircraft is required for reasons of national security.
DEFENSE VISUAL FLIGHT RULES− Rules applicable to flights within an ADIZ conducted under the visual
flight rules in 14 CFR part 91.
(See AIR DEFENSE IDENTIFICATION ZONE.)
(Refer to 14 CFR part 91.)
(Refer to 14 CFR part 99.)
DELAY ASSIGNMENT (DAS)− Delays are distributed to aircraft based on the traffic management program
parameters. The delay assignment is calculated in 15−minute increments and appears as a table in Traffic Flow
Management System (TFMS).
DELAY COUNTDOWN TIMER (DCT)− The display of the delay that must be absorbed by a flight prior to
crossing a Meter Reference Element (MRE) to meet the TBFM Scheduled Time of Arrival (STA). It is calculated
by taking the difference between the frozen STA and the Estimated Time of Arrival (ETA).
DELAY INDEFINITE (REASON IF KNOWN) EXPECT FURTHER CLEARANCE (TIME)− Used by A TC
to inform a pilot when an accurate estimate of the delay time and the reason for the delay cannot immediately
be determined; e.g., a disabled aircraft on the runway, terminal or center area saturation, weather below landing
minimums, etc.
(See EXPECT FURTHER CLEARANCE (TIME).)
DEPARTURE CENTER− The ARTCC having jurisdiction for the airspace that generates a flight to the impacted
airport.
DEPARTURE CLEARANCE (DCL) APPLICATION– The DCL application provides up to nine Selectable
Fields for the tower controller to enter all other clearance information.
DEPARTURE CONTROL− A function of an approach control facility providing air traffic control service for
departing IFR and, under certain conditions, VFR aircraft.
(See APPROACH CONTROL FACILITY.)
(Refer to AIM.)
DEPARTURE SEQUENCING PROGRAM− A program designed to assist in achieving a specified interval over
a common point for departures.
DEPARTURE TIME− The time an aircraft becomes airborne.
DEPARTURE VIEWER− A capability within the Traffic Flow Management System (TFMS) that provides
combined displays for monitoring departure by fixes and departure airports. Traffic management personnel can
customize the displays by selecting the departure airports and fixes of interest. The information displayed is the
demand for the resource (fix or departure airport) in time bins with the flight list and a flight history for one flight
at a time. From the display, flights can be selected for route amendment, one or more at a time, and the Route
Amendment Dialogue (RAD) screen automatically opens for easy route selection and execution. Reroute
options are based on Coded Departure Route (CDR) database and Trajectory Options Set (TOS) (when
available).
DESCEND VIA– An abbreviated ATC clearance that requires compliance with a published procedure lateral
path and associated speed restrictions and provides a pilot-discretion descent to comply with published altitude
restrictions.
DESCENT SPEED ADJUSTMENTS− Speed deceleration calculations made to determine an accurate VTA.
These calculations start at the transition point and use arrival speed segments to the vertex.
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PCG D−3
DESIGNATED COMMON TRAFFIC ADVISORY FREQUENCY (CTAF) AREA− In Alaska, in addition to
being designated for the purpose of carrying out airport advisory practices while operating to or from an airport
without an operating airport traffic control tower, a CTAF may also be designated for the purpose of carrying
out advisory practices for operations in and through areas with a high volume of VFR traffic.
DESIRED COURSE−
a. True− A predetermined desired course direction to be followed (measured in degrees from true north).
b. Magnetic− A predetermined desired course direction to be followed (measured in degrees from local
magnetic north).
DESIRED TRACK− The planned or intended track between two waypoints. It is measured in degrees from either
magnetic or true north. The instantaneous angle may change from point to point along the great circle track
between waypoints.
DETRESFA (DISTRESS PHASE) [ICAO]− The code word used to designate an emergency phase wherein there
is reasonable certainty that an aircraft and its occupants are threatened by grave and imminent danger or require
immediate assistance.
DEVIATION−
a. A departure from a current clearance, such as an off course maneuver to avoid weather or turbulence.
b. Where specifically authorized in the CFRs and requested by the pilot, ATC may permit pilots to deviate
from certain regulations.
DH−
(See DECISION HEIGHT.)
DH [ICAO]−
(See ICAO Term DECISION ALTITUDE/ DECISION HEIGHT.)
DIGITAL-AUTOMATIC TERMINAL INFORMATION SERVICE (D-ATIS) − The service provides text
messages to aircraft, airlines, and other users outside the standard reception range of conventional ATIS via
landline and data link communications to the cockpit. Also, the service provides a computer−synthesized voice
message that can be transmitted to all aircraft within range of existing transmitters. The Terminal Data Link
System (TDLS) D-ATIS application uses weather inputs from local automated weather sources or manually
entered meteorological data together with preprogrammed menus to provide standard information to users.
Airports with D-ATIS capability are listed in the Chart Supplement U.S.
DIGITAL TARGET− A computer−generated symbol representing an aircraft’s position, based on a primary
return or radar beacon reply, shown on a digital display.
DIGITAL TERMINAL AUTOMATION SYSTEM (DTAS)− A system where digital radar and beacon data is
presented on digital displays and the operational program monitors the system performance on a real−time basis.
DIGITIZED TARGET− A computer−generated indication shown on an analog radar display resulting from a
primary radar return or a radar beacon reply.
DIRECT− Straight line flight between two navigational aids, fixes, points, or any combination thereof. When
used by pilots in describing off-airway routes, points defining direct route segments become compulsory
reporting points unless the aircraft is under radar contact.
DIRECTLY BEHIND− An aircraft is considered to be operating directly behind when it is following the actual
flight path of the lead aircraft over the surface of the earth except when applying wake turbulence separation
criteria.
DISCRETE BEACON CODE−
(See DISCRETE CODE.)
DISCRETE CODE− As used in the Air Traffic Control Radar Beacon System (ATCRBS), any one of the 4096
selectable Mode 3/A aircraft transponder codes except those ending in zero zero; e.g., discrete codes: 0010, 1201,
1/22/26 Pilot/Controller Glossary
Pilot/Controller Glossary 2/20/25
PCG D−4
2317, 7777; nondiscrete codes: 0100, 1200, 7700. Nondiscrete codes are normally reserved for radar facilities
that are not equipped with discrete decoding capability and for other purposes such as emergencies (7700), VFR
aircraft (1200), etc.
(See RADAR.)
(Refer to AIM.)
DISCRETE FREQUENCY− A separate radio frequency for use in direct pilot-controller communications in air
traffic control which reduces frequency congestion by controlling the number of aircraft operating on a particular
frequency at one time. Discrete frequencies are normally designated for each control sector in en route/terminal
ATC facilities. Discrete frequencies are listed in the Chart Supplement U.S. and the DoD FLIP IFR En Route
Supplement.
(See CONTROL SECTOR.)
DISPLACED THRESHOLD− A threshold that is located at a point on the runway other than the designated
beginning of the runway.
(See THRESHOLD.)
(Refer to AIM.)
DISTANCE MEASURING EQUIPMENT (DME) − Equipment (airborne and ground) used to measure, in
nautical miles, the slant range distance of an aircraft from the DME navigational aid.
(See TACAN.)
(See VORTAC.)
DISTRESS− A condition of being threatened by serious and/or imminent danger and of requiring immediate
assistance.
DIVE BRAKES−
(See SPEED BRAKES.)
DIVERSE VECTOR AREA− In a radar environment, that area in which a prescribed departure route is not
required as the only suitable route to avoid obstacles. The area in which random radar vectors below the
MV A/MIA, established in accordance with the TERPS criteria for diverse departures, obstacles and terrain
avoidance, may be issued to departing aircraft.
DIVERSION (DVRSN)− Flights that are required to land at other than their original destination for reasons
beyond the control of the pilot/company, e.g. periods of significant weather.
DME−
(See DISTANCE MEASURING EQUIPMENT.)
DME FIX− A geographical position determined by reference to a navigational aid which provides distance and
azimuth information. It is defined by a specific distance in nautical miles and a radial, azimuth, or course (i.e.,
localizer) in degrees magnetic from that aid.
(See DISTANCE MEASURING EQUIPMENT.)
(See FIX.)
DME SEPARATION− Spacing of aircraft in terms of distances (nautical miles) determined by reference to
distance measuring equipment (DME).
(See DISTANCE MEASURING EQUIPMENT.)
DoD FLIP− Department of Defense Flight Information Publications used for flight planning, en route, and
terminal operations. FLIP is produced by the National Geospatial−Intelligence Agency (NGA) for world-wide
use. United States Government Flight Information Publications (en route charts and instrument approach
procedure charts) are incorporated in DoD FLIP for use in the National Airspace System (NAS).
DOMESTIC AIRSPACE− Airspace which overlies the continental land mass of the United States plus Hawaii
and U.S. possessions. Domestic airspace extends to 12 miles offshore.
DOMESTIC NOTICE− A special notice or notice containing graphics or plain language text pertaining to almost
every aspect of aviation, such as military training areas, large scale sporting events, air show information, Special
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PCG D−5
Traffic Management Programs (STMPs), and airport −specific information. These notices are applicable to
operations within the United States and can be found on the Domestic Notices website.
DOWNBURST− A strong downdraft which induces an outburst of damaging winds on or near the ground.
Damaging winds, either straight or curved, are highly divergent. The sizes of downbursts vary from 1/2 mile
or less to more than 10 miles. An intense downburst often causes widespread damage. Damaging winds, lasting
5 to 30 minutes, could reach speeds as high as 120 knots.
DOWNLINK– CPDLC message sent from the flight deck to ATC.
DOWNWIND LEG−
(See TRAFFIC PATTERN.)
DP−
(See INSTRUMENT DEPARTURE PROCEDURE.)
DRA−
(See DEBRIS RESPONSE AREA.)
DRAG CHUTE− A parachute device installed on certain aircraft which is deployed on landing roll to assist in
deceleration of the aircraft.
DROP ZONE− Any pre-determined area upon which parachutists or objects land after making an intentional
parachute jump or drop.
(Refer to 14 CFR §105.3, Definitions)
DSP−
(See DEPARTURE SEQUENCING PROGRAM.)
DTAS−
(See DIGITAL TERMINAL AUTOMATION SYSTEM.)
DUE REGARD− A phase of flight wherein an aircraft commander of a State-operated aircraft assumes
responsibility to separate his/her aircraft from all other aircraft.
(See also FAA Order JO 7110.65, Para 1−2−1, WORD MEANINGS.)
DUTY RUNWAY−
(See RUNWAY IN USE/ACTIVE RUNWAY/DUTY RUNWAY.)
DV A−
(See DIVERSE VECTOR AREA.)
DVFR−
(See DEFENSE VISUAL FLIGHT RULES.)
DVFR FLIGHT PLAN− A flight plan filed for a VFR aircraft which intends to operate in airspace within which
the ready identification, location, and control of aircraft are required in the interest of national security.
DVRSN−
(See DIVERSION.)
DYNAMIC− Continuous review, evaluation, and change to meet demands.
DYNAMIC RESTRICTIONS− Those restrictions imposed by the local facility on an “as needed” basis to
manage unpredictable fluctuations in traffic demands.
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PCG E−1
E-MSAW−
(See EN ROUTE MINIMUM SAFE ALTITUDE WARNING.)
EAS−
(See EN ROUTE AUTOMATION SYSTEM.)
EDCT−
(See EXPECT DEPARTURE CLEARANCE TIME.)
EDST−
(See EN ROUTE DECISION SUPPORT TOOL)
EFC−
(See EXPECT FURTHER CLEARANCE (TIME).)
ELIGIBILITY– Designates which sector is eligible to exchange CPDLC messages with a specific aircraft.
ELT−
(See EMERGENCY LOCATOR TRANSMITTER.)
EMBEDDED ROUTE TEXT− An EDST notification that an ADR/ADAR/AAR has been applied to the flight
plan. Within the route field, sub−fields consisting of an adapted route or an embedded change in the route are
color−coded in cyan with cyan brackets around the sub−field.
(See EN ROUTE DECISION SUPPORT TOOL.)
EMERGENCY− A distress or an urgency condition.
EMERGENCY AUTOLAND SYSTEM− This system, if activated, will determine an optimal airport, plot a
course, broadcast the aircraft’s intentions, fly to the airport, land, and (depending on the model) shut down the
engines. Though the system will broadcast the airc raft’s intentions, the controller should assume that
transmissions to the aircraft will not be acknowledged.
EMERGENCY DESCENT MODE− This automated system senses conditions conducive to hypoxia (cabin
depressurization). If an aircraft is equipped and the system is activated, it is designed to turn the aircraft up to
90 degrees, then descend to a lower altitude and level off, giving the pilot(s) time to recover.
EMERGENCY LOCATOR TRANSMITTER (ELT)− A radio transmitter attached to the aircraft structure which
operates from its own power source on 121.5 MHz and 243.0 MHz. It aids in locating downed aircraft by
radiating a downward sweeping audio tone, 2-4 times per second. It is designed to function without human action
after an accident.
(Refer to 14 CFR part 91.)
(Refer to AIM.)
ENHANCED FLIGHT VISION SYSTEM (EFVS)− An EFVS is an installed aircraft system which uses an
electronic means to provide a display of the forward external scene topography (the natural or man−made features
of a place or region especially in a way to show their relative positions and elevation) through the use of imaging
sensors, including but not limited to forward−looking infrared, millimeter wave radiometry, millimeter wave
radar, or low−light level image intensification. An EFVS includes the display element, sensors, computers and
power supplies, indications, and controls. An operator’s authorization to conduct an EFVS operation may have
provisions which allow pilots to conduct IAPs when the reported weather is below minimums prescribed on the
IAP to be flown.
ENHANCED SPECIAL REPORTING SERVICE (eSRS)– An automated service used to enhance search and
rescue operations that provides flight service specialists in Alaska direct information from the aircraft’s
registered tracking device.
1/22/26 Pilot/Controller Glossary
Pilot/Controller Glossary 2/20/25
PCG E−2
EN ROUTE AIR TRAFFIC CONTROL SERVICES− Air traffic control service provided aircraft on IFR flight
plans, generally by centers, when these aircraft are operating between departure and destination terminal areas.
When equipment, capabilities, and controller workload permit, certain advisory/assistance services may be
provided to VFR aircraft.
(See AIR ROUTE TRAFFIC CONTROL CENTER.)
(Refer to AIM.)
EN ROUTE AUTOMATION SYSTEM (EAS)− The complex integrated environment consisting of situation
display systems, surveillance systems and flight data processing, remote devices, decision support tools, and
the related communications equipment that form the heart of the automated IFR air traffic control system. It
interfaces with automated terminal systems and is used in the control of en route IFR aircraft.
(Refer to AIM.)
EN ROUTE CHARTS−
(See AERONAUTICAL CHART.)
EN ROUTE DECISION SUPPORT TOOL (EDST) − An automated tool provided at each Radar Associate
position in selected En Route facilities. This tool utilizes flight and radar data to determine present and future
trajectories for all active and proposal aircraft and provides enhanced automated flight data management.
EN ROUTE DESCENT− Descent from the en route cruising altitude which takes place along the route of flight.
EN ROUTE HIGH ALTITUDE CHARTS−
(See AERONAUTICAL CHART.)
EN ROUTE LOW ALTITUDE CHARTS−
(See AERONAUTICAL CHART.)
EN ROUTE MINIMUM SAFE ALTITUDE WARNING (E−MSAW)− A function of the EAS that aids the
controller by providing an alert when a tracked aircraft is below or predicted by the computer to go below a
predetermined minimum IFR altitude (MIA).
EN ROUTE TRANSITION−
(See SEGMENTS OF A SID/STAR.)
EN ROUTE TRANSITION WAYPOINT
(See SEGMENTS OF A SID/STAR.)
eSRS–
(See ENHANCED SPECIAL REPORTING SERVICE.)
EST−
(See ESTIMATED.)
ESTABLISHED− To be stable or fixed at an altitude or on a course, route, route segment, heading, instrument
approach or departure procedure, etc.
ESTABLISHED ON RNP (EoR) CONCEPT– A system of authorized instrument approaches, ATC procedures,
surveillance, and communication requirements that allow aircraft operations to be safely conducted with
approved reduced separation criteria once aircraft are established on a PBN segment of a published instrument
flight procedure.
ESTIMATED (EST)−When used in NOTAMs “EST” is a contraction that is used by the issuing authority only
when the condition is expected to return to service prior to the expiration time. Using “EST” lets the user know
that this NOTAM has the possibility of returning to service earlier than the expiration time. Any NOTAM which
includes an “EST” will be auto−expired at the designated expiration time.
ESTIMATED ELAPSED TIME [ICAO]− The estimated time required to proceed from one significant point to
another.
(See ICAO Term TOTAL ESTIMATED ELAPSED TIME.)
Pilot/Controller Glossary 1/22/26
Pilot/Controller Glossary2/20/25
PCG E−3
ESTIMATED OFF-BLOCK TIME [ICAO]− The estimated time at which the aircraft will commence movement
associated with departure.
ESTIMATED POSITION ERROR (EPE)−
(See Required Navigation Performance)
ESTIMATED TIME OF ARRIV AL− The time the flight is estimated to arrive at the gate (scheduled operators)
or the actual runway on times for nonscheduled operators.
ESTIMATED TIME EN ROUTE− The estimated flying time from departure point to destination (lift-off to
touchdown).
ETA−
(See ESTIMATED TIME OF ARRIVAL.)
ETE−
(See ESTIMATED TIME EN ROUTE.)
EXECUTE MISSED APPROACH− Instructions issued to a pilot making an instrument approach which means
continue inbound to the missed approach point and execute the missed approach procedure as described on the
Instrument Approach Procedure Chart or as previously assigned by ATC. The pilot may climb immediately to
the altitude specified in the missed approach procedure upon making a missed approach. No turns should be
initiated prior to reaching the missed approach point. When conducting an ASR or PAR approach, execute the
assigned missed approach procedure immediately upon receiving instructions to “execute missed approach.”
(Refer to AIM.)
EXPECT (ALTITUDE) AT (TIME) or (FIX)− Used under certain conditions to provide a pilot with an altitude
to be used in the event of two-way communications failure. It also provides altitude information to assist the pilot
in planning.
(Refer to AIM.)
EXPECT DEPARTURE CLEARANCE TIME (EDCT)− The runway release time assigned to an aircraft in a
traffic management program and shown on the flight progress strip as an EDCT.
(See GROUND DELAY PROGRAM.)
EXPECT FURTHER CLEARANCE (TIME) − The time a pilot can expect to receive clearance beyond a
clearance limit.
EXPECT FURTHER CLEARANCE VIA (AIRWAYS, ROUTES OR FIXES)− Used to inform a pilot of the
routing he/she can expect if any part of the route beyond a short range clearance limit differs from that filed.
EXPEDITE− Used by ATC when prompt compliance is required to avoid the development of an imminent
situation. Expedite climb/descent normally indicates to a pilot that the approximate best rate of climb/descent
should be used without requiring an exceptional change in aircraft handling characteristics.
1/22/26 Pilot/Controller Glossary
Pilot/Controller Glossary2/20/25
PCG F−1
FAA−RECOGNIZED IDENTIFICATION AREA (FRIA)− A defined geographic area where persons can
operate UAS without remote identification, provided they maintain visual line of sight.
FAF−
(See FINAL APPROACH FIX.)
FALLEN HERO– Remains of fallen members of the United States military are often returned home by aircraft.
These flights may be identified with the phrase “FALLEN HERO” added to the remarks section of the flight plan,
or they may be transmitted via air/ground communications. If able, these flights will receive priority handling.
FAST FILE− An FSS system whereby a pilot files a flight plan via telephone that is recorded and later transcribed
for transmission to the appropriate air traffic facility. (Alaska only.)
FAWP− Final Approach Waypoint
FEATHERED PROPELLER− A propeller whose blades have been rotated so that the leading and trailing edges
are nearly parallel with the aircraft flight path to stop or minimize drag and engine rotation. Normally used to
indicate shutdown of a reciprocating or turboprop engine due to malfunction.
FEDERAL AIRWAYS−
(See LOW ALTITUDE AIRWAY STRUCTURE.)
FEEDER FIX− The fix depicted on Instrument Approach Procedure Charts which establishes the starting point
of the feeder route.
FEEDER ROUTE− A route depicted on instrument approach procedure charts to designate routes for aircraft
to proceed from the en route structure to the initial approach fix (IAF).
(See INSTRUMENT APPROACH PROCEDURE.)
FERRY FLIGHT− A flight for the purpose of:
a. Returning an aircraft to base.
b. Delivering an aircraft from one location to another.
c. Moving an aircraft to and from a maintenance base. Ferry flights, under certain conditions, may be
conducted under terms of a special flight permit.
FIELD ELEV ATION−
(See AIRPORT ELEVATION.)
FILED− Normally used in conjunction with flight plans, meaning a flight plan has been submitted to ATC.
FILED EN ROUTE DELAY− Any of the following preplanned delays at points/areas along the route of flight
which require special flight plan filing and handling techniques.
a. Terminal Area Delay. A delay within a terminal area for touch-and-go, low approach, or other terminal area
activity.
b. Special Use Airspace Delay. A delay within a Military Operations Area, Restricted Area, Warning Area,
or ATC Assigned Airspace.
c. Aerial Refueling Delay. A delay within an Aerial Refueling Track or Anchor.
FILED FLIGHT PLAN − The flight plan as filed with an ATS unit by the pilot or his/her designated
representative without any subsequent changes or clearances.
FINAL− Commonly used to mean that an aircraft is on the final approach course or is aligned with a landing
area.
(See FINAL APPROACH COURSE.)
(See FINAL APPROACH-IFR.)
(See SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE.)
Pilot/Controller Glossary 2/20/25
PCG F−2
FINAL APPROACH [ICAO]− That part of an instrument approach procedure which commences at the specified
final approach fix or point, or where such a fix or point is not specified.
a. At the end of the last procedure turn, base turn or inbound turn of a racetrack procedure, if specified; or
b. At the point of interception of the last track specified in the approach procedure; and ends at a point in the
vicinity of an aerodrome from which:
1. A landing can be made; or
2. A missed approach procedure is initiated.
FINAL APPROACH COURSE− A bearing/radial/track of an instrument approach leading to a runway or an
extended runway centerline all without regard to distance.
FINAL APPROACH FIX− The fix from which the final approach (IFR) to an airport is executed and which
identifies the beginning of the final approach segment. It is designated on Government charts by the Maltese
Cross symbol for nonprecision approaches and the lightning bolt symbol, designating the PFAF, for precision
approaches; or when ATC directs a lower-than-published glideslope/path or vertical path intercept altitude, it
is the resultant actual point of the glideslope/path or vertical path intercept.
(See FINAL APPROACH POINT.)
(See GLIDESLOPE INTERCEPT ALTITUDE.)
(See SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE.)
FINAL APPROACH-IFR− The flight path of an aircraft which is inbound to an airport on a final instrument
approach course, beginning at the final approach fix or point and extending to the airport or the point where a
circle-to-land maneuver or a missed approach is executed.
(See FINAL APPROACH COURSE.)
(See FINAL APPROACH FIX.)
(See FINAL APPROACH POINT.)
(See SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE.)
(See ICAO term FINAL APPROACH.)
FINAL APPROACH POINT− The point, applicable only to a nonprecision approach with no depicted FAF
(such as an on airport VOR), where the aircraft is established inbound on the final approach course from the
procedure turn and where the final approach descent may be commenced. The FAP serves as the FAF and
identifies the beginning of the final approach segment.
(See FINAL APPROACH FIX.)
(See SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE.)
FINAL APPROACH SEGMENT−
(See SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE.)
FINAL APPROACH SEGMENT [ICAO] − That segment of an instrument approach procedure in which
alignment and descent for landing are accomplished.
FINAL CONTROLLER− The controller providing information and final approach guidance during PAR and
ASR approaches utilizing radar equipment.
(See RADAR APPROACH.)
FINAL GUARD SERVICE− A value added service provided in conjunction with LAA/RAA only during
periods of significant and fast changing weather conditions that may affect landing and takeoff operations.
FINAL MONITOR AID− A high resolution color display that is equipped with the controller alert system
hardware/software used to monitor the no transgression zone (NTZ) during simultaneous parallel approach
operations. The display includes alert algorithms providing the target predictors, a color change alert when a
target penetrates or is predicted to penetrate the no transgression zone (NTZ), synthesized voice alerts, and digital
mapping.
(See RADAR APPROACH.)
Pilot/Controller Glossary2/20/25
PCG F−3
FINAL MONITOR CONTROLLER− Air Traffic Control Specialist assigned to radar monitor the flight path
of aircraft during simultaneous parallel (approach courses spaced less than 9000 feet/9200 feet above 5000 feet)
and simultaneous close parallel approach operations. Each runway is assigned a final monitor controller during
simultaneous parallel and simultaneous close parallel ILS approaches.
FIR−
(See FLIGHT INFORMATION REGION.)
FIRST PERSON VIEW− UAS operation in which imagery is transmitted to the UAS pilot by an onboard UA
camera.
FIRST TIER CENTER− An ARTCC immediately adjacent to the impacted center.
FIS−B−
(See FLIGHT INFORMATION SERVICE−BROADCAST.)
FIX− A geographical position determined by visual reference to the surface, by reference to one or more radio
NA V AIDs, by celestial plotting, or by another navigational device.
FIX BALANCING− A process whereby aircraft are evenly distributed over several available arrival fixes
reducing delays and controller workload.
FLAG− A warning device incorporated in certain airborne navigation and flight instruments indicating that:
a. Instruments are inoperative or otherwise not operating satisfactorily, or
b. Signal strength or quality of the received signal falls below acceptable values.
FLAG ALARM−
(See FLAG.)
FLAMEOUT− An emergency condition caused by a loss of engine power.
FLAMEOUT PATTERN− An approach normally conducted by a single-engine military aircraft experiencing
loss or anticipating loss of engine power or control. The standard overhead approach starts at a relatively high
altitude over a runway (“high key”) followed by a continuous 180 degree turn to a high, wide position (“low key”)
followed by a continuous 180 degree turn final. The standard straight-in pattern starts at a point that results in
a straight-in approach with a high rate of descent to the runway. Flameout approaches terminate in the type
approach requested by the pilot (normally fullstop).
FLIGHT CHECK− A call sign prefix used by FAA aircraft engaged in flight inspection/certification of
navigational aids and flight procedures. The word “recorded” may be added as a suffix; e.g., “Flight Check 320
recorded” to indicate that an automated flight inspection is in progress in terminal areas.
(See FLIGHT INSPECTION.)
(Refer to AIM.)
FLIGHT DA TA [FSS]– The primary task of the FSS flight data position is information management. Flight data
services include the development, translation, processing, and coordination of aeronautical, meteorological, and
aviation information.
FLIGHT FOLLOWING−
(See TRAFFIC ADVISORIES.)
FLIGHT INFORMATION REGION− An airspace of defined dimensions within which Flight Information
Service and Alerting Service are provided.
a. Flight Information Service. A service provided for the purpose of giving advice and information useful for
the safe and efficient conduct of flights.
b. Alerting Service. A service provided to notify appropriate organizations regarding aircraft in need of search
and rescue aid and to assist such organizations as required.
FLIGHT INFORMATION SERVICE− A service provided for the purpose of giving advice and information
useful for the safe and efficient conduct of flights.
Pilot/Controller Glossary 2/20/25
PCG F−4
FLIGHT INFORMATION SERVICE−BROADCAST (FIS−B)− A ground broadcast service provided through
the ADS−B Broadcast Services network over the UAT data link that operates on 978 MHz. The FIS−B system
provides pilots and flight crews of properly equipped aircraft with a cockpit display of certain aviation weather
and aeronautical information.
FLIGHT INSPECTION− Inflight investigation and evaluation of a navigational aid to determine whether it
meets established tolerances.
(See FLIGHT CHECK.)
(See NAVIGATIONAL AID.)
FLIGHT LEVEL− A level of constant atmospheric pressure related to a reference datum of 29.92 inches of
mercury. Each is stated in three digits that represent hundreds of feet. For example, flight level (FL) 250
represents a barometric altimeter indication of 25,000 feet; FL 255, an indication of 25,500 feet.
(See ICAO term FLIGHT LEVEL.)
FLIGHT LEVEL [ICAO]− A surface of constant atmospheric pressure which is related to a specific pressure
datum, 1013.2 hPa (1013.2 mb), and is separated from other such surfaces by specific pressure intervals.
Note 1: A pressure type altimeter calibrated in accordance with the standard atmosphere:
a. When set to a QNH altimeter setting, will indicate altitude;
b. When set to a QFE altimeter setting, will indicate height above the QFE reference datum; and
c. When set to a pressure of 1013.2 hPa
(1013.2 mb), may be used to indicate flight levels.
Note 2: The terms ‘height’ and ‘altitude,’ used in Note 1 above, indicate altimetric rather than geometric heights
and altitudes.
FLIGHT LINE− A term used to describe the precise movement of a civil photogrammetric aircraft along a
predetermined course(s) at a predetermined altitude during the actual photographic run.
FLIGHT MANAGEMENT SYSTEMS− A computer system that uses a large data base to allow routes to be
preprogrammed and fed into the system by means of a data loader. The system is constantly updated with respect
to position accuracy by reference to conventional navigation aids. The sophisticated program and its associated
data base ensures that the most appropriate aids are automatically selected during the information update cycle.
FLIGHT PATH− A line, course, or track along which an aircraft is flying or intended to be flown.
(See COURSE.)
(See TRACK.)
FLIGHT PLAN− Specified information relating to the intended flight of an aircraft that is filed electronically,
orally, or in writing with an FSS, third−party vendor, or an ATC facility.
(See FAST FILE.)
(See FILED.)
(Refer to AIM.)
FLIGHT PLAN AREA (FPA)− The geographical area assigned to a flight service station (FSS) for the purpose
of establishing primary responsibility for services that may include search and rescue for VFR aircraft, issuance
of NOTAMs, pilot briefings, inflight services, broadcast services, emergency services, flight data processing,
international operations, and aviation weather services. Large consolidated FSS facilities may combine FPAs
into larger areas of responsibility (AOR).
(See FLIGHT SERVICE STATION.)
(See TIE-IN FACILITY.)
FLIGHT RECORDER− A general term applied to any instrument or device that records information about the
performance of an aircraft in flight or about conditions encountered in flight. Flight recorders may make records
of airspeed, outside air temperature, vertical acceleration, engine RPM, manifold pressure, and other pertinent
variables for a given flight.
(See ICAO term FLIGHT RECORDER.)
Pilot/Controller Glossary2/20/25
PCG F−5
FLIGHT RECORDER [ICAO]− Any type of recorder installed in the aircraft for the purpose of complementing
accident/incident investigation.
Note: See Annex 6 Part I, for specifications relating to flight recorders.
FLIGHT SERVICE STATION (FSS) − An air traffic facility which provides pilot briefings, flight plan
processing, en route flight advisories, search and rescue services, and assistance to lost aircraft and aircraft in
emergency situations. FSS also relay ATC clearances, process Notices to Airmen, and broadcast aviation
weather and aeronautical information. In Alaska, FSS provide Airport Advisory Services.
(See FLIGHT PLAN AREA.)
(See TIE-IN FACILITY.)
FLIGHT STANDARDS DISTRICT OFFICE− An FAA field office serving an assigned geographical area and
staffed with Flight Standards personnel who serve the aviation industry and the general public on matters relating
to the certification and operation of air carrier and general aviation aircraft. Activities include general
surveillance of operational safety, certification of airmen and aircraft, accident prevention, investigation,
enforcement, etc.
FLIGHT TERMINATION− The intentional and deliberate process of terminating the flight of a UA in the event
of an unrecoverable lost link, loss of control, or other failure that compromises the safety of flight.
FLIGHT TEST− A flight for the purpose of:
a. Investigating the operation/flight characteristics of an aircraft or aircraft component.
b. Evaluating an applicant for a pilot certificate or rating.
FLIGHT VISIBILITY−
(See VISIBILITY.)
FLIP−
(See DoD FLIP.)
FLY-BY WAYPOINT− A fly-by waypoint requires the use of turn anticipation to avoid overshoot of the next
flight segment.
FLY HEADING (DEGREES)− Informs the pilot of the heading he/she should fly. The pilot may have to turn
to, or continue on, a specific compass direction in order to comply with the instructions. The pilot is expected
to turn in the shorter direction to the heading unless otherwise instructed by ATC.
FLY-OVER WAYPOINT− A fly-over waypoint precludes any turn until the waypoint is overflown and is
followed by an intercept maneuver of the next flight segment.
FLY VISUAL TO AIRPORT−
(See PUBLISHED INSTRUMENT APPROACH PROCEDURE VISUAL SEGMENT.)
FLYAWAY− When the pilot is unable to effect control of the aircraft and, as a result, the UA is not operating
in a predictable or planned manner.
FMA−
(See FINAL MONITOR AID.)
FMS−
(See FLIGHT MANAGEMENT SYSTEM.)
FORMATION FLIGHT− More than one aircraft which, by prior arrangement between the pilots, operate as a
single aircraft with regard to navigation and position reporting. Separation between aircraft within the formation
is the responsibility of the flight leader and the pilots of the other aircraft in the flight. This includes transition
periods when aircraft within the formation are maneuvering to attain separation from each other to effect
individual control and during join-up and breakaway.
a. A standard formation is one in which a proximity of no more than 1 mile laterally or longitudinally and
within 100 feet vertically from the flight leader is maintained by each wingman.
8/7/25 Pilot/Controller Glossary
Pilot/Controller Glossary 2/20/25
PCG F−6
b. Nonstandard formations are those operating under any of the following conditions:
1. When the flight leader has requested and ATC has approved other than standard formation dimensions.
2. When operating within an authorized altitude reservation (ALTRV) or under the provisions of a letter
of agreement.
3. When the operations are conducted in airspace specifically designed for a special activity.
(See ALTITUDE RESERVATION.)
(Refer to 14 CFR part 91.)
FRC−
(See REQUEST FULL ROUTE CLEARANCE.)
FREEZE/FROZEN− Terms used in referring to arrivals which have been assigned ACLTs and to the lists in
which they are displayed.
FREEZE HORIZON− The time or point at which an aircraft’s STA becomes fixed and no longer fluctuates with
each radar update. This setting ensures a constant time for each aircraft, necessary for the metering controller
to plan his/her delay technique. This setting can be either in distance from the meter fix or a prescribed flying
time to the meter fix.
FREEZE SPEED PARAMETER− A speed adapted for each aircraft to determine fast and slow aircraft. Fast
aircraft freeze on parameter FCLT and slow aircraft freeze on parameter MLDI.
FRIA−
(See FAA−RECOGNIZED IDENTIFICATION AREA.)
FRICTION MEASUREMENT− A measurement of the friction characteristics of the runway pavement surface
using continuous self-watering friction measurement equipment in accordance with the specifications,
procedures and schedules contained in AC 150/5320−12, Measurement, Construction, and Maintenance of Skid
Resistant Airport Pavement Surfaces.
FSDO−
(See FLIGHT STANDARDS DISTRICT OFFICE.)
FSPD−
(See FREEZE SPEED PARAMETER.)
FSS−
(See FLIGHT SERVICE STATION.)
FUEL DUMPING− Airborne release of usable fuel. This does not include the dropping of fuel tanks.
(See JETTISONING OF EXTERNAL STORES.)
FUEL REMAINING− A phrase used by either pilots or controllers when relating to the fuel remaining on board
until actual fuel exhaustion. When transmitting such information in response to either a controller question or
pilot initiated cautionary advisory to air traffic control, pilots will state the APPROXIMATE NUMBER OF
MINUTES the flight can continue with the fuel remaining. All reserve fuel SHOULD BE INCLUDED in the
time stated, as should an allowance for established fuel gauge system error.
FUEL SIPHONING− Unintentional release of fuel caused by overflow, puncture, loose cap, etc.
FUEL VENTING−
(See FUEL SIPHONING.)
FUSED TARGET-
(See DIGITAL TARGET)
FUSION [STARS]- the combination of all available surveillance sources (airport surveillance radar [ASR], air
route surveillance radar [ARSR], ADS-B, etc.) into the display of a single tracked target for air traffic control
separation services. FUSION is the equivalent of the current single-sensor radar display. FUSION performance
Pilot/Controller Glossary2/20/25
PCG F−7
is characteristic of a single-sensor radar display system. Terminal areas use mono-pulse secondary surveillance
radar (ASR 9, Mode S or ASR 11, MSSR).
Pilot/Controller Glossary2/20/25
PCG G−1
GATE HOLD PROCEDURES− Procedures at selected airports to hold aircraft at the gate or other ground
location whenever departure delays exceed or are anticipated to exceed 15 minutes. The sequence for departure
will be maintained in accordance with initial call−up unless modified by flow control restrictions. Pilots should
monitor the ground control/clearance delivery frequency for engine start/taxi advisories or new proposed
start/taxi time if the delay changes.
GCA−
(See GROUND CONTROLLED APPROACH.)
GDP−
(See GROUND DELAY PROGRAM.)
GENERAL A VIATION− That portion of civil aviation that does not include scheduled or unscheduled air
carriers or commercial space operations.
(See ICAO term GENERAL AVIATION.)
GENERAL A VIATION [ICAO] − All civil aviation operations other than scheduled air services and
nonscheduled air transport operations for remuneration or hire.
GEO MAP− The digitized map markings associated with the ASR-9 Radar System.
GLIDEPATH−
(See GLIDESLOPE.)
GLIDEPATH [ICAO]− A descent profile determined for vertical guidance during a final approach.
GLIDEPATH INTERCEPT ALTITUDE−
(See GLIDESLOPE INTERCEPT ALTITUDE.)
GLIDESLOPE− Provides vertical guidance for aircraft during approach and landing. The glideslope/glidepath
is based on the following:
a. Electronic components emitting signals which provide vertical guidance by reference to airborne
instruments during instrument approaches such as ILS; or,
b. Visual ground aids, such as V ASI, which provide vertical guidance for a VFR approach or for the visual
portion of an instrument approach and landing.
c. PAR. Used by ATC to inform an aircraft making a PAR approach of its vertical position (elevation) relative
to the descent profile.
(See ICAO term GLIDEPATH.)
GLIDESLOPE INTERCEPT ALTITUDE− The published minimum altitude to intercept the glideslope in the
intermediate segment of an instrument approach. Government charts use the lightning bolt symbol to identify
this intercept point. This intersection is called the Precise Final Approach fix (PFAF). ATC directs a higher
altitude, the resultant intercept becomes the PFAF.
(See FINAL APPROACH FIX.)
(See SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE.)
GLOBAL NA VIGA TION SATELLITE SYSTEM (GNSS)− GNSS refers collectively to the worldwide
positioning, navigation, and timing determination capability available from one or more satellite constellations.
A GNSS constellation may be augmented by ground stations and/or geostationary satellites to improve integrity
and position accuracy.
(See GROUND−BASED AUGMENTATION SYSTEM.)
(See SATELLITE−BASED AUGMENTATION SYSTEM.)
Pilot/Controller Glossary 2/20/25
PCG G−2
GLOBAL NA VIGA TION SATELLITE SYSTEM MINIMUM EN ROUTE IFR ALTITUDE (GNSS MEA)−
The minimum en route IFR altitude on a published ATS route or route segment which assures acceptable Global
Navigation Satellite System reception and meets obstacle clearance requirements.
(Refer to 14 CFR part 91.)
(Refer to 14 CFR part 95.)
GLOBAL POSITIONING SYSTEM (GPS)− GPS refers to the worldwide positioning, navigation and timing
determination capability available from the U.S. satellite constellation. The service provided by GPS for civil
use is defined in the GPS Standard Positioning System Performance Standard. GPS is composed of space,
control, and user elements.
GNSS [ICAO]−
(See GLOBAL NAVIGATION SATELLITE SYSTEM.)
GNSS MEA−
(See GLOBAL NAVIGATION SATELLITE SYSTEM MINIMUM EN ROUTE IFR ALTITUDE.)
GO AHEAD− Proceed with your message. Not to be used for any other purpose.
GO AROUND− Instructions for a pilot to abandon his/her approach to landing. Additional instructions may
follow. Unless otherwise advised by ATC, a VFR aircraft or an aircraft conducting visual approach should
overfly the runway while climbing to traffic pattern altitude and enter the traffic pattern via the crosswind leg.
A pilot on an IFR flight plan making an instrument approach should execute the published missed approach
procedure or proceed as instructed by ATC; e.g., “Go around” (additional instructions if required).
(See LOW APPROACH.)
(See MISSED APPROACH.)
GPD−
(See GRAPHIC PLAN DISPLAY.)
GPS−
(See GLOBAL POSITIONING SYSTEM.)
GRAPHICAL AIRMEN’S METEOROLOGICAL INFORMATION− A graphical depiction of weather that
may be hazardous to aircraft, but are less severe than SIGMETs. G−AIRMETS are issued 3 hours apart for a
period of up to 12 hours into the future for the lower 48 states and coastal waters. The weather hazards depicted
can be:
a. Moderate turbulence
b. Low-level windshear
c. Strong surface winds greater than 30 knots
d. Moderate icing
e. Freezing level
f. Mountain obscuration
g. IFR
(See AIRMET.)
(See CONVECTIVE SIGMET.)
(See CWA.)
(See SAW.)
(See SIGMET.)
(Refer to AIM.)
GRAPHIC PLAN DISPLAY (GPD)− A view available with EDST that provides a graphic display of aircraft,
traffic, and notification of predicted conflicts. Graphic routes for Current Plans and Trial Plans are displayed
upon controller request.
(See EN ROUTE DECISION SUPPORT TOOL.)