Capsule expands or contracts in response to changes in
pressure.
ANC Air Navigation Commission
ANP Actual Navigation Performance
ANPRM Advance Notice of Public Rule Making
ANS (1) Area Navigation System
(2) Ambient Noise Sensor
ANSI American National Standards Institute
ANT Antenna
ANTC Advanced Networking Test Center
AOA Angle Of Attack
AOC (1) Airport Operational Communications
(2) Air/Oil Cooler
(3) Aeronautical Operational Control
(4) Airport Obstruction Chart
(5) Aircraft Operational Control
AOCC Airline Operation Control Center
AODC Age of Data,Clock (GPS term)
AODE Age of Data,Ephemeris (GPS term)
AOG Aircraft On Ground
8
AOHE Air/Oil Heat Exchanger
AOPA Aircraft Owners and Pilots Association
AOPG Aerodrome Operations Group
AOR Atlantic Ocean Region
A/P Autopilot. A computer commanded system for con-
trolling aircraft control surfaces.
APA Autopilot Amplifier
APALS Autonomous Precision Approach and Landing System
APANGPRIG ICAO Asia/Pacific Air Navigation Planning and
Implementation Regional Group
APB Auxiliary Power Breaker
APC (1) Autopilot Computer
(2) Aeronautical Public Correspondence
APEX IMA Application/Executive Software Interface
APP Approach Control
APPR Approach
APU Auxiliary Power Unit
APUC Auxiliary Power Unit Controller
AQP Avionics Qualification Procedure
A-QPSK Aeronautical Quadrature Phase Shift Keying
AQS Advanced Quality System
ARA FAA Research and Acquisitions
ARES Advanced Railroad Electronics System
ARINC Aeronautical Radio,Inc.
ARF Airline Risk Factor
ARP Air Data Reference Panel
ARS Automated Radar Summary chart. These are hourly
generated charts showing location and intensity of
radar echoes.
ARSR Air Route Surveillance Radar
ART Automatic Reserve Thrust
ARTCC Air-Route Traffic Control Center. Approximately 20
centers cover the air traffic routes in the United
States using numerous radars and radio communica-
tion sets.
ARTS Automated Terminal Radar System
ASA (1) Autoland Status Annunciator (AFDS)
(2) Aircraft Separation Assurance
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