| A | B |
|---|
| AAE | above aerodrome elevation |
| ACAS | airborne collision avoidance system |
| ACC | area control centre |
| AD | airworthiniess directive |
| ADF | automatic direction finder |
| ADIZ | air defence identification zone |
| AGL | above ground level |
| AIRMET | short-term meterological information |
| AME | aircraft maintenance engineer |
| APU | auxiliary power unit |
| ARCAL | aircraft radio control of aerodrome lighting |
| ASDA | accelerate stop distance available |
| ASI | airspeed indicator |
| ASL | above sea level |
| ASR | airport surveillance radar |
| ATC | air traffic control |
| ATF | aerodrome trafffic frequency |
| ATIS | automatic terminal information service |
| ATPL | airline transport pilot licence |
| ATS | air traffic services |
