12/2/21 

Pilot/Controller Glossary 

A 

AAR

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(See AIRPORT ARRIVAL RATE.) 

ABBREVIATED IFR FLIGHT PLANS

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 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 VFR­on­top. 

(See VFR-ON-TOP.) 
(Refer to AIM.) 

ABEAM

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  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

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  To terminate a preplanned aircraft 

maneuver; e.g., an aborted takeoff. 

ABRR

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(See AIRBORNE REROUTE) 

ACC [ICAO]

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(See ICAO term AREA CONTROL CENTER.) 

ACCELERATE­STOP  DISTANCE  AVAILABLE

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The runway plus stopway length declared available 
and suitable for the acceleration and deceleration of 
an airplane aborting a takeoff. 

ACCELERATE­STOP DISTANCE AVAILABLE 
[ICAO]

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 The length of the take­off run available plus 

the length of the stopway if provided. 

ACDO

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(See AIR CARRIER DISTRICT OFFICE.) 

ACKNOWLEDGE

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  Let me know that you have 

received and understood this message. 

ACL

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(See AIRCRAFT LIST.) 

ACLS

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(See AUTOMATIC CARRIER LANDING 

SYSTEM.) 

ACROBATIC FLIGHT

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 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]

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 Maneuvers inten­

tionally performed by an aircraft involving an abrupt 
change in its attitude, an abnormal attitude, or an 
abnormal variation in speed. 

ACTIVE RUNWAY

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(See RUNWAY IN USE/ACTIVE RUNWAY/DUTY 

RUNWAY.) 

ACTUAL NAVIGATION PERFORMANCE 
(ANP)

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(See REQUIRED NAVIGATION 

PERFORMANCE.) 

ADDITIONAL SERVICES

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 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 ser­

vices 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 

PCG A

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