| AAF | Airway Facilities Service |
| AAI | FAA Office of Accident Investigation |
| AAP | Advanced Automation Program |
| AAR | Airport Acceptance Rate |
| AAS | Advanced Automation System |
| AAT | Associate Administrator for Air Traffic |
| AC | Advisory Circular |
| ACAA | Air Carrier Association of America |
| ACDO | Air Carrier District Office |
| ACEP | Airport Capacity Enhancement Plan |
| ADAP | Airport Development Aid Program |
| ADAS | Automated Weather Observing System Data Acquisition System |
| ADC | Air Defense Command |
| ADIC | ATS Interfacility Data Communications |
| ADL | Aeronautical Data Link |
| ADO | Airline Dispatch Office |
| ADO | Airport District Office |
| ADS | Automatic Dependent Surveillance |
| ADSIM | Airfield Delay Simulation Model |
| AEE | FAA Office of Environment and Energy |
| AEEC | Airlines Electronic Engineering Committee |
| AF | Air Force |
| AFMS | Automatic Flight Management System |
| AFS | Airways Facilities Sector |
| AFSS | Automated Flight Service Station |
| AGI | FAA Office of Government and Industry Affairs |
| AILS | Automatic Instrument Landing System |
| AIM | Aeronautical Information Manual |
| AIP | Airport Improvement Program |
| AIRPAC | Advisor for the Intelligent Resolution of Predicted Aircraft |
| AIS | Aeronautical Information System |
| ALPA | Airlines Pilots Association |
| ALSF | Approach Lighting System With Sequenced Flashing Lights |
| ALTRV | Altitude Reservation |
| AMASS | Airport Movement Area Safety System |
| AMCC | Air Route Traffic Control Center Maintenance Control Center |
| AMIC | Area Manager in Charge |
| AMIS | Aircraft Management Information System |
| AND | Associate Administrator for NAS Development |
| ANM | Northwest Mountain Region |
| ANS | NAS Transitions and Implementation |
| AO | Acronymic Obfuscation |
| AOA | FAA Office of the Administrator |
| AOAS | Advanced Oceanic Automation System |
| AOC | Airline Operational Control Center |
| AOP | NAS Operations |
| AOPA | Aircraft Owners and Pilots Association |
| AOS | Operational Support Service |
| APM | Approach Path Monitor |
| ARC | Administrator's Review Committee |
| ARC | Airlines Reporting Corporation |
| ARC | Aviation Review Committee |
| AREA | Automated En Route Air Traffic Control |
| ARINC | Aeronautical Radio Incorporated |
| ARSR | Air Route Surveillance Radar |
| ARTCC | Air Route Traffic Control Center |
| ARTS | Automated Radar Terminal System |
| ASAS | Aviation Safety Analysis System |
| ASD | Aircraft Situation Display |
| ASDE | Airport Surface Detection Equipment |
| ASOS | Automated Surface Observing System |
| ASP | Arrival Sequencing Program |
| ASR | Airport Surveillance Radar |
| ASR | Airways Facilities Spectrum Policy and Management |
| ATA | Airline Transport Association |
| ATC | Air Traffic Control |
| ATCA | Air Traffic Control Association |
| ATCAA | ATC Assigned Airspace |
| ATCRBS | Air Traffic Control Radar Beacon System |
| ATCSCC | Air Traffic Control Systems Command Center |
| ATCT | Airport Traffic Control Tower |
| ATIDS | Airport Surface Target Identification System |
| ATIS | Automated Terminal Information Service |
| ATM | Air Traffic Manager |
| ATMS | Automated Training Management System |
| ATN | Aeronautical Telecommunications Network |
| ATO | Air Traffic Operations |
| ATOMS | Air Traffic Management Operations Management Systems |
| ATS | Air Traffic Services |
| AVN | Aviation System Standards |
| AWOS | Automated Weather Observing System |
| AWP | Aviation Weather Processor |
| AWP | Western Pacific Region |
