A/C Aircraft
AC Advisory Circular Alternative Current
ACD Airworthiness Compliance Document
ACJ Advisory Circular-Joint
ACL ATC Clearance
ACM ATC Communication Management
ACT Additional Center Tank
ADIRU Air Data Inertial Reference Unit
ADR Air Data Reference
ADS-B Automatic Dependent Surveillance-Broadcast
ADS-C Automatic Dependent Surveillance-Contract
AEO All Engines Operative
AFM Airplane Flight Manual
AGL Above Ground Level
AIME Autonomous Integrity Monitoring Extrapolation
ALD Actual Landing Distance
AMC ATC Microphone Check Acceptable Means of Compliance
AMJ Advisory Material-Joint
AMM Aircraft Maintenance Manual
AOA Angle of Attack
AOC Airlines Operational Control
AP Autopilot
APU Auxiliary Power Unit
AR Authorization Required
ARINC Aeronautical Radio INC
ASD Accelerate Stop Distance
ASDA Accelerate Stop Distance Available
ASI Air Speed Indicator
ATA Air Transport Association
ATC Air Traffic Control
ATS Air Traffic Service
ATSA-AIRB Air Traffic Situational Awareness - Airborne
ATSA-ITP Air Traffic Situational Awareness - In Trail Procedures
ATSA-VSA Air Traffic Situational Awareness - Visual Separation on Approach

ATSAW Airborne Traffic Situational Awareness
ATSU Air Traffic Service Unit
AWO All Weather Operations

BC Back Course
BSCU Braking and Steering Control Unit

C/B Circuit Breaker
CAA Civil Aviation Authority