| 1. | A | Alfa |
| 2. | AAAE | American Association of Airport Executives |
| 3. | AAI | Arrival Aircraft Interval |
| 4. | AAM | Air-to-Air Missile |
| 5. | AAR | Airport Acceptance Rate |
| 6. | AAS | Airport Advisory Service |
| 7. | AB | Afterburner |
| 8. | ABC | After Bottom Center |
| 9. | ABS | AbsoluteAUTO BRAKE SYSTEM |
| 10. | AC | Air ConditioningAIRCRAFT |
| 11. | AC | Alternating Current - Advisory Circular |
| 12. | ACARS | ARINC Communication Addressing and Reporting System |
| 13. | ACAS | Airborne Collision and Avoidance System |
| 14. | ACC | Area Control Center - Active Clearance Control |
| 15. | ACCEL | Acceleration |
| 16. | ACDO | Air Carrier District Office |
| 17. | ACESS | Advanced Cabin Entertainment and Service System |
| 18. | ACLS | Automatic Carrier Landing System |
| 19. | ACLT | Actual Calculated Landing Time |
| 20. | ACM | Air Cycle Machine |
