| 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 |
| AREA | Automated En Route Air Traffic Control |
| 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 |
| AMIC | Area Manager in Charge |
| AMIS | Aircraft Management Information System |
| AMCC | Air Route Traffic Control Center Maintenance Control Center |
| 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 |
| 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 |
| BFO | Blazing Flash of the Obvious (DOD) |
| BRITE | Bright Radar Indicator Tower Equipment |
| BUEC | Backup Emergency Communications |
| CA | Conflict Alert |
| CAASD | Center for Advanced Aviation System Development |
| CATTS | Computerized Air Traffic Training System |
| CAD | Computer Aided Drawing |
| CAEG | Computer Aided Engineering Graphics |
| CAMI | Civil Aeronautical Medical Institute |
| CAP | Civil Air Patrol |
| CARF | Central Altitude Reservation Function |
| CASA | Controller Automated Spacing Aid |
| CBI | Computer Based Instruction |
| CD | Common Digitizer |
| CDC | Computer Display Channel |
| CDM | Collaborative Decision Making |
| CDS | Central Dispatch System |
| CDT | Controlled Departure Time |
| CDTI | Cockpit Display of Traffic |
| CDV | Compressed Digital Video |
| CENRAP | Center Radar Arts Presentation |
| CERAP | Center Radar Approach Control |
| CFR | Code of Federal Regulations |
| CHI | Computer Human Interface |
| CIP | Capital Investment Plan |
| CNS | Communications, Navigation, and Surveillance |
| COTR | Contracting Officer's Technical Representative |
| COTS | Commercial-Off-The-Shelf |
| CP | Conflict Probe |
| CPDLC | Controller Pilot Data Link Communications |
| CRA | Conflict Resolution Advisory |
| CRDA | Converging Runway Display Aid |
| CTAS | Center TRACON Automation System |
| CWP | Central Weather Processor |
| DARC | Direct Access Radar Channel |
| DARP | Dynamic Aircraft Route Planning |
| DASI | Direct Altimeter Setting Indicator |
| DB | Decibel |
| DBRITE | Digital Bright Radar Indicator Tower Equipment |
| DCC | Direct Channel Complex |
| DF | Direction Finder |
| DGNSS | Differential Global Navigation Satellite System |
| DGPS | Differential Global Positioning System |
| DIA | Denver International Airport |
| DLAP | Data Link Applications Processor |
| DME | Distance Measuring Equipment |
| DOD | Department of Defense |
| DOT | Department of Transportation |
| DOTS | Dynamic Ocean Track System |
| DOVE | DSR Oceanic VSCS En Route Implementation Working Group |
| DSP | Departure Sequencing Program |
| DSR | Display System Replacement |
| DSS | Decision Support System |
| DUATS | Direct User Access Terminal System |
| DVOR | Doppler Very High Frequency Omni Directional Range |
| DVRS | Digital Voice Recorder System |
| EARS | En Route Analysis and Reporting System |
| EARTS | En Route Automated Radar Tracking System |
| EDC | Early Display Configuration |
| EDCT | Estimated Departure Control Time |
| EDI | Electronic Data Interchange |
| EDMS | Electronic Document Management Systems |
| EPA | Environmental Protection Agency |
| ERM | En Route Spacing Program |
| ESP | Enroute Sequencing Program |
| ETMS | Enhanced Traffic management Systems |
| EVCS | Emergency Voice Communications Systems |
| EVFR | Electronic Visual Flight Rules |
| FAATC | Federal Aviation Administration Technical Center |
| FAATSAT | Federal Aviation Administration Telecommunications Satellite |
| FADE | FAA/Airline Data Exchange |
| FANS | Future Air Navigation System |
| FARM | Fielded Automation Requirements Management |
| FAST | Final Approach Spacing Tool |
| FCC | Federal Communications Commission |
| FCM | Flight Schedule Monitor |
| FCT | Federal Contract Tower |
| FDP/RDP | Flight Data Processing/Radar Data Processing |
| FIAO | Flight Inspection Area Office |
| FIR | Flight Information Region |
| FIS | Flight Information Services |
| FLIP | Flight Information Publication |
| FLTCK | Flight Check |
| FONSI | Finding of No Significant Impact |
| FMA | Final Monitor Aid |
| FMS | Flight Management System |
| FPL | Full Performance Level |
| FPS | Military Primary Radar |
| FSDPS | Flight Service Data Processing System |
| FSM | Flight Schedule Monitor |
| FTS | Federal Telecommunications System |
| GA | General Aviation |
| GAO | General Accounting Office |
| GDE | Ground Delay Enhancements |
| GDP | Ground Delay Program |
| GENOT | General Notice |
| GETS | Government Emergency Telecommunications Service |
| GLONASS | Global Orbiting Navigational Satellite System |
| GMCC | General National Airspace System Maintenance Control Center |
| GNAS | General National Airspace System |
| GNSS | Global Navigation Satellite System |
| GOMP | Gulf of Mexico Program |
| GPS | Global Positioning System |
| GSA | General Services Administration |
| GUI | Graphic User Interface |
| GWDS | Graphic Weather Display System |
| HCS | Host Computer System |
| HID | Host Interface Display |
| HID/NAS/LAN | Host Interface Device/National Airspace System/Local Area Network |
| HUD | Heads Up Display |
| I&I | Impact and Implementation |
| IAPA | Instrument Approach Procedures Automation |
| IATA | International Air Transport Association |
| ICAO | International Civil Aviation Organization |
| ICSS | Integrated Communications Switching System |
| IFR | Instrument Flight Rules |
| ILS | Instrument Landing System |
| IMC | Instrument Meteorological Conditions |
| INM | Integrated Noise Model |
| IOC | Initial Operating Capability |
| IOT&E | Independent Operational Test and Evaluation |
| IPT | Integrated Product Team |
| ISC | Initial System Capability |
| ITC | In-Trail Climb |
| ITD | In-Trail Descent |
| ITWS | Integrated Terminal Weather System |
| IVT | Interactive Video Teletraining |
| IWGDS | Interim Weather Graphic-Display System |
| JAI | Joint Acceptance Inspection |
| JSS | Joint Surveillance System |
| kHz | Kilohertz |
| LAAS | Local Area Augmentation System |
| LABS | Los Angeles Basin Study |
| LAGPS | Local Area Global Positioning System |
| LAN | Local Area Network |
| LAHSO | Land and Hold Short Operations |
| LAWRS | Limited Aviation Weather Reporting Service |
| LCC | Life Cycle Cost |
| LFME | Local Flow Management Enhancements |
| LINCS | Leased Interfacility National Airspace System Communications System |
| LLWAS | Low-Level Windshear Alert System |
| LOA | Letter of Agreement |
| LOB | Line Of Business |
| LOC | Localizer |
| LOM | Locator Outer Marker |
| LORAN | Long-Range Navigation |
| LRR | Long Range Radar |
| M1FC | Model 1 Full Capacity |
| MALSR | Medium-Intensity Approach Lighting System With Runway Alignment Indicator |
| MAP | Missed Approach Procedure |
| MARSA | Military Assumes Responsibility for Separation |
| MCI | Mode C Intruder |
| METAR | Aviation Routine Weather Report |
| mGz | Megahertz |
| MLS | Microwave Landing System |
| MNPS | Minimum Navigation Performance Specification |
| MNS | Mission Needs Statement |
| MOA | Military Operations Area |
| MODE C | Altitude Reporting Mode of Secondary Radar |
| MODE S | Mode Select; Discrete Addressable Secondary Radar System With Data Link |
| MODEM | Modulator-Demodulator |
| MOU | Memorandum of Understanding |
| MSA | Minimum Safe Altitude |
| MSAW | Minimum Safe Altitude Warning |
| MTD | Moving Target Detection |
| MTR | Military Training Route |
| MWP | Meteorological Weather Processor |
| NADIN | National Airspace Data Interchange Network |
| NAILS | National Airspace Integrated Logistics Support |
| NAPRS | National Airspace Performance Reporting System |
| NAR | National Airspace Review |
| NARACS | National Radio Communications System |
| NAS | National Airspace System |
| NASDAC | National Aviation Safety Data Analysis Center |
| NATCA | National Air Traffic Controllers Association |
| NATS | National Air Traffic Service |
| NAVAIDS | Navigational Aids |
| NBAA | National Business Aircraft Association |
| NBCAP | National Beacon Code Allocation Plan |
| NCP | NAS Change Proposal |
| NEXRAD | Next-Generation Weather Radar |
| NFP | NIMS Premier Facility |
| NICS | National Airspace System Interfacility Communications System |
| NIMS | NAS Infrastructure Management System |
| NIST | National Institute of Standards and Technologies |
| NM | Nautical Mile |
| NMCC | National Maintenance Control Center |
| NOAA | National Oceanic and Atmospheric Administration |
| NOM | NAS Operations Manager |
| NOREP | National Oceanic Review and Enhancement Program |
| NOTAM | Notice to Airmen |
| NPIAS | National Plan for Integrated Airport Systems |
| NPM | NAS Program Manager/Management |
| NPR | National Performance Review |
| NPRM | Notice of Proposed Rule Making |
| NRP | National Route Program |
| NTSB | National Transportation Safety Board |
| NWS | National Weather Service |
| OAMP | Off-Line Aircraft Management Program |
| OAP | Oceanic Automation Program |
| OAS | Oceanic Automation System |
| OASIS | Operational and Supportability Implementation System |
| OATS | Office Automation Technology Services |
| OCA | Oceanic Control Area |
| OCC | Operations Control Center |
| ODALS | Omnidirectional Approach Lighting Systems |
| ODAPS | Oceanic Display and Planning System |
| ODL | Oceanic Data Link |
| OE/AAA | Obstruction Evaluation/Airport Airspace Analysis |
| OMB | Office of Management and Budget |
| OMEGA | Very Low Radio Navigation System |
| OPI | Office of Primary Interest |
| OPSNET | Operations Network |
| ORD | Operational Readiness Demonstration |
| OS | Operating System |
| OS | Operational Shakedown & Cutover |
| OSRWG | Oceanic Separation Reduction Working Group |
| OSDS | Oceanic System Development and Support |
| OSHA | Occupational Safety and Health Administration |
| OT&E | Operational Test and Evaluation |
| OTPS | Oceanic Traffic Planning System |
| PAMRI | Peripheral Adapter Module Replacement Item |
| PAPI | Precision Approach Path Indicator |
| PAR | Precision Approach Radar |
| PASS | Professional Airway Systems Specialists |
| PATS | Precision Approach Tracking System |
| PCS | Power Conditioning System |
| PDC | Pre-Departure Clearance |
| PFAST | Passive Final Approach Spacing Tool |
| PIP | Program Implementation Plan |
| PIREP | Pilot Weather Report |
| PM | Preventive Maintenance |
| POC | Point Of Contact |
| PRM | Precision Runway Monitor |
| PSL | Projected Service Life |
| PTR | Program Technical/Trouble Report |
| PVD | Plan View Display |
| PWI | Proximity Warning Indicator |
| P2R2 | Preferred Route Reduction Program |
| QA | Quality Assurance |
| R& D | Research and Development |
| R,E&D | Research, Engineering and Development |
| RAPCON | Radar Approach Control |
| RAT | Risk Assessment Team |
| RCAG | Remote Communications Air/Ground |
| RCE | Radio Control Equipment |
| RCF | Remote Communications Facility |
| RCO | Remote Communications Outlet |
| REGIS | Regional Information System |
| REIL | Runway End Identification Lights |
| RFI | Radio Frequency Interference |
| RFI | Return on Future Investment |
| RIAP | Runway Incursion Action Plan |
| RIAT | Runway Incursion Action Team |
| RIP | Runway Incursion Program |
| RML | Radar Microwave Link |
| RMM | Remote Maintenance Monitoring |
| RMMS | Remote Maintenance Monitoring Systems |
| RNAV | Area Navigation |
| RNP-10 | Required Navigation Performance |
| RPV | Remotely Piloted Vehicle |
| RSL | Runway Status Light |
| RTCA | Radio Technical Commission for Aeronautics |
| RTE | RTE |
| RTR | Remote Transmitter/Receiver |
| RTS | Return to Service |
| RVR | Runway Visual Range |
| RVSM | Reduced Vertical Separation Minima |
| RX | Receiver |
| SAMS | Special Use Airspace Management System |
| SAR | Search and Rescue |
| SAWRS | Supplemental Aviation Weather Reporting Service |
| SCAT | Southern California Area TRACON ( Metroplex) |
| SECRA | Secondary Radar |
| SETA | System Engineering and Technical Assistance |
| SID | Standard Instrument Departure |
| SIAP | Standard Instrument Flight Procedures |
| SIGMET | Significant Meteorological Information |
| SIMMOD | Airspace and Airport Simulation Model |
| SPIFR | Single Pilot IFR |
| SMA | Surface Monitor Aid |
| SMA | Surface Movement Advisor |
| SMMC | System Maintenance Monitor Console |
| SMGCS | Surface Movement Guidance and Control System |
| SOC | Service Operations Center |
| SOP | Standard Operating Practice |
| SPA | Society for the Prevention of Acronyms |
| SSC | System Support Center |
| SST | System Shakedown Testing |
| STAR | Standard Terminal Arrival Route |
| STARS | Standard Terminal Area Radar System |
| STARS | Standard Terminal Automation Replacement System |
| STMP | Special Traffic Management Program |
| STOL | Short Take - Off and Landing |
| STT | Staffing to Traffic |
| STVS | Small Tower Voice Switch |
| SUA | Special Use Airspace |
| SUPCOM | Supervisors Committee (AAT AND AAF) |
| SUPS | Suspected Unapproved Parts System |
| SVFR | Special Visual Flight Rules |
| SWAP | Severe Weather Avoidance Procedure/Program |
| TAC | Tactical Air Command (USAF) |
| TACAN | Tactical Air Navigation |
| TATCA | Terminal Air Traffic Control Automation |
| TCAP | Traffic Count Automation Program |
| TCAS | Traffic Alert and Collision Avoidance System |
| TCCC | Tower Control Computer Complex |
| TCVR | Transceiver |
| TDLS | Tower Data-Link Services |
| TDWR | Terminal Doppler Weather Radar |
| TERP | Terminal Instrument Procedures |
| TFM | Traffic Flow Management |
| TFR | Temporary Flight Restriction |
| TMA | Traffic Management Advisor |
| TMI | Traffic Management Initiatives |
| TMS | Traffic Management System |
| TMU | Traffic Management Unit |
| TOC | Technical Operations Center |
| TP | Telecommunication Processor |
| TRACON | Terminal Radar Approach Control |
| TSSC | Terminal Support Services Contract |
| TSARTS | Terminal Stand-Alone Radar Training System |
| TVSR | Terminal Voice Switch Replacement |
| TWIP | Terminal Weather Information for Pilots |
| TX | Transmitter |
| UBA | User Benefits Applications |
| UBI | User Benefits Infrastructure |
| UHF | Ultra High Frequency |
| UPR | User Preferred Route |
| UPS | Uninterruptable Power Supply |
| UPT | User Preferred Trajectory |
| URET | User Request Evaluation Tool |
| USAF | United States Air Force |
| USCG | United States Coast Guard |
| USNS | United States Notices to Airmen System |
| UTC | Coordinated Universal Time (ZULU) |
| VASI | Visual Approach Slope Indicator |
| VDL | Very High Frequency Data Link |
| VEARS | VSCS Emergency Access Radio System |
| VFR | Visual Flight Rules |
| VHF | Very High Frequency |
| VMC | Visual Meteorological Conditions |
| VOR | Very High Frequency Omnidirectional Range |
| VOR/DME | Very High Frequency Omnidirectional Range Colocated with Distance Measuring Equipment |
| VORTAC | Very High Frequency
Omnidirectional Range Colocated Tactical Air Navigation |
| VRRP | Voice Recorder Replacement Program |
| VSCS | Voice Switching Communications System |
| VTOL | Vertical Take-Off and Landing |
| WAAS | Wide Area Augmentation System |
| WADGPS | Wide Area Differential Global Positioning System |
| WAN | Wide Area Network |
| WARP | Weather and Radar Processor |
| WMSCR | Weather Message Switching Center Replacement |
| WRS | Wide Area Augmentation System Reference Station |
| WSR | Weather Surveillance Radar |
| WX | Weather |
| ZAB | Albuquerque ARTCC |
| ZAN | Anchorage ARTCC |
| ZAU | Chicago ARTCC |
| ZBW | Boston ARTCC |
| ZDC | Washington ARTCC |
| ZDV | Denver ARTCC |
| ZFW | Fort Worth ARTCC |
| ZHU | Houston ARTCC |
| ZID | Indianapolis ARTCC |
| ZJX | Jacksonville ARTCC |
| ZKC | Kansas City ARTCC |
| ZLA | Los Angeles ARTCC |
| ZLC | Salt Lake City ARTCC |
| ZMA | Miami ARTCC |
| ZME | Memphis ARTCC |
| ZMP |