This starter list focuses on common U.S. civil-aviation usage. Context controls the meaning; always use current FAA, NOAA/NWS or regulatory source material for operational interpretation.
Airframe and Powerplant
Maintenance & AirworthinessFAA mechanic certificate ratings commonly used when referring to certificated aircraft mechanics.
Advisory Circular
Regulations & CertificationFAA publication used to provide guidance and acceptable means of showing compliance; an AC is not itself a regulation unless incorporated by reference or otherwise made binding.
Airworthiness Directive
Maintenance & AirworthinessA legally enforceable FAA rule requiring corrective action for an unsafe condition in a product when the directive applies.
Automatic Dependent Surveillance–Broadcast
Avionics & NavigationAircraft surveillance technology that broadcasts position and other flight information; ADS-B Out requirements apply in specified airspace.
Above Ground Level
OperationsAltitude or height measured above the local ground surface.
Aeronautical Information Manual
OperationsFAA manual containing basic flight information and ATC procedures for use in the National Airspace System.
Aeronautical Information Publication
OperationsState-issued publication containing aeronautical information of lasting character essential to air navigation.
Aircraft Report
Aviation WeatherA report of actual in-flight weather conditions, often automated and commonly used on international routes.
Airmen's Meteorological Information
Aviation WeatherWeather advisory terminology for hazards generally less severe than SIGMET criteria; CONUS text AIRMETs have been replaced by G-AIRMETs.
Air Route Traffic Control Center
Airspace & ATCFAA en route facility responsible for controlling IFR traffic and providing services across a large geographic area.
Automated Surface Observing System
Aviation WeatherAutomated weather observing system used to report surface weather conditions.
Air Traffic Control
Airspace & ATCService provided by the appropriate authority to promote the safe, orderly and expeditious flow of air traffic.
Automatic Terminal Information Service
Airspace & ATCContinuous broadcast of recorded non-control terminal information at selected airports.
Airline Transport Pilot
Regulations & CertificationThe highest level of FAA pilot certificate; specific privileges and limitations are defined in 14 CFR Part 61.
Automated Weather Observing System
Aviation WeatherAutomated airport weather observation equipment with capabilities that vary by system level.
Code of Federal Regulations
Regulations & CertificationCodification of general and permanent federal regulations; aviation rules are primarily found in Title 14.
Common Traffic Advisory Frequency
Airspace & ATCFrequency designated for airport advisory practices at airports without an operating control tower or when a tower is closed.
Distance Measuring Equipment
Avionics & NavigationRadio navigation equipment that determines slant-range distance from a compatible ground station.
Emergency Locator Transmitter
Safety & EquipmentEmergency transmitter intended to aid search-and-rescue location after an accident or activation.
Federal Aviation Administration
GeneralU.S. Department of Transportation agency responsible for civil aviation safety and operation of the National Airspace System.
Full Authority Digital Engine Control
Aircraft SystemsDigital engine-control system with full authority over engine operation within its designed control logic.
Fixed Base Operator
Airports & Ground OperationsCommercial provider of airport services such as fuel, parking, hangar, passenger support or maintenance.
Flight Standards District Office
Regulations & CertificationFAA field office supporting flight standards oversight, certification and operational matters within its assigned area.
Graphical Airmen's Meteorological Information
Aviation WeatherGraphical advisory depicting weather that may be hazardous to aircraft but generally below SIGMET severity; used for the contiguous U.S.
Graphical Forecasts for Aviation
Aviation WeatherAviation Weather Center graphical forecast environment combining observations, forecasts and hazard information.
Global Navigation Satellite System
Avionics & NavigationGeneric term for satellite navigation constellations and associated services; GPS is the U.S. constellation.
Global Positioning System
Avionics & NavigationU.S. satellite-based positioning and navigation system used extensively in aviation.
International Civil Aviation Organization
GeneralUnited Nations specialized agency that develops international standards and recommended practices for civil aviation.
Instrument Flight Rules
OperationsRules governing flight when operating under an IFR clearance and the applicable instrument-flight requirements.
Instrument Landing System
Avionics & NavigationGround-based precision approach system providing lateral and vertical guidance to an equipped aircraft.
Minimum Equipment List
Maintenance & AirworthinessFAA-authorized operator-specific list and procedures that may permit operation with certain equipment inoperative under stated conditions.
Aviation Routine Weather Report
Aviation WeatherStandard coded format for routine surface aviation weather observations.
Military Operations Area
Airspace & ATCSpecial use airspace established to separate or segregate certain nonhazardous military activities from IFR traffic and identify the activity for VFR traffic.
Mean Sea Level
OperationsAltitude reference based on mean sea level.
National Airspace System
Airspace & ATCIntegrated U.S. system of airspace, navigation facilities, airports, ATC services, rules and supporting infrastructure.
Navigational Aid
Avionics & NavigationFacility or equipment used to assist aircraft navigation.
Notice to Airmen
OperationsTime-critical aeronautical information concerning the establishment, condition or change of a facility, service, procedure or hazard.
National Transportation Safety Board
SafetyIndependent U.S. agency that investigates civil aviation accidents and selected incidents and issues safety recommendations.
Performance-Based Navigation
Avionics & NavigationNavigation concept based on required system performance rather than a particular sensor or ground facility.
Pilot in Command
OperationsPilot designated as responsible for and having final authority over the operation and safety of the flight.
Pilot Report
Aviation WeatherPilot-provided report of actual in-flight weather conditions such as turbulence, icing, cloud layers or visibility.
Area Navigation
Avionics & NavigationNavigation capability allowing flight on desired paths within coverage/capability of the navigation infrastructure and onboard systems.
Required Navigation Performance
Avionics & NavigationPBN specification that includes onboard performance monitoring and alerting.
Significant Meteorological Information
Aviation WeatherWeather advisory for conditions significant to the safety of all aircraft, including specified severe hazards.
Standard Instrument Departure
Airspace & ATCPublished IFR departure procedure used to transition aircraft from the terminal area to the en route structure.
Standard Terminal Arrival Route
Airspace & ATCPublished IFR arrival route used to transition aircraft from the en route structure toward a terminal area.
Supplemental Type Certificate
Regulations & CertificationFAA approval of a major change in type design to an already type-certificated product.
Special Use Airspace
Airspace & ATCAirspace where certain activities must be confined or where limitations may be imposed on nonparticipating aircraft.
Terminal Aerodrome Forecast
Aviation WeatherCoded forecast of expected meteorological conditions at an airport during a specified valid period.
Terrain Awareness and Warning System
Safety & EquipmentAircraft system designed to provide alerts related to potentially hazardous terrain proximity.
Type Certificate
Regulations & CertificationFAA design approval showing an aircraft, engine or propeller type design meets applicable airworthiness standards.
Traffic Alert and Collision Avoidance System
Safety & EquipmentAirborne collision-avoidance system that interrogates compatible transponders and provides traffic advisories and, for appropriate systems, resolution advisories.
Temporary Flight Restriction
Airspace & ATCTemporary restriction on aircraft operations in a defined area for a specified purpose and period.
Terminal Radar Approach Control
Airspace & ATCFAA terminal facility that provides radar approach, departure and related services in busy terminal areas.
Unmanned Aircraft System
Emerging AviationUnmanned aircraft and the associated elements required for safe and efficient operation.
Coordinated Universal Time
OperationsInternational time standard used throughout aviation for weather, flight planning and operational timestamps.
Visual Flight Rules
OperationsRules governing flight conducted under visual-flight requirements and applicable weather/airspace limitations.
VHF Omnidirectional Range
Avionics & NavigationGround-based radio navigation system providing azimuth/course information.
Wide Area Augmentation System
Avionics & NavigationFAA satellite-based augmentation system that improves GPS accuracy, integrity and availability for approved aviation operations.
Weather
Aviation WeatherCommon aviation contraction for weather.