AC: Advisory Circular
ADDS: Aviation Digital Data Service
ADF: Automatic Direction Finder
ADIZ: Air Defense Identification Zone
ADS-B: Automatic Dependent Surveillance Broadcast
A/FD: Airport/Facility Directory
AGL: Above Ground Level
ALS: Approach Light System
ALSF1: Approach Light System with Sequence Flashers
ALSF2: Approach Light System with Sequence Flasher II
ARFF: Aircraft Rescue and Fire Fighting
ARTCC: Air Route Traffic Control Center
ARTS: Automated Radar Terminal System
ASM: Available Seat Mile
ASOS: Automated Surface Observation System
ASR: Airport Surveillance Radar
ASRS: Aviation Safety Reporting System
ATC: Air Traffic Control
ATCT: Air Traffic Control Tower
ATIS: Automatic Terminal Information System
ATP: Airline Transport Pilot
AWOS: Automated Weather Observation System
BFR: Biennial Flight Review
CDI: Course Deviation Indicator
CFI: Certified Flight Instructor
CFI-I: Certified Flight Instructor - Instrument Rating
CFIT: Controlled Flight into Terrain
CTAF: Common Traffic Advisory Frequency
DA: Decision Altitude
DH: Decision Height
DME: Distance Measuring Equipment
DP: Departure Procedure
DUATS: Direct User Access Terminal System
EFAS: En Route Flight Advisory Service
ELT: Emergency Locator Transmitter
ETA: Estimated Time of Arrival
ETE: Estimated Time En Route
FAA: Federal Aviation Administration
FAF: Final Approach Fix
FAR/AIM: Federal Aviation Regulations and Aeronautical Information Manual
FAWP: Final Approach Waypoint
FD: Flight Director
FITS: FAA-Industry Training Standards
FMS: Flight Management System
FSDO: Flight Standards District Office
FSS: Flight Service Station
GPS: Global Positioning System
GPWS: Ground Proximity Warning System
HIRL: High Intensity Runway Lights
HIWAS: Hazardous Inflight Weather Advisory System
HUD: Heads-Up Display
IAF: Initial Approach Fix
IAP: Instrument Approach Procedure
IAS: Indicated Airspeed
IAWP: Initial Approach Waypoint
ICAO: International Civil Aviation Organization
IFR: Instrument Flight Rules
ILS: Instrument Landing System
IMC: Instrument Meteorological Conditions
IPC: Instrument Proficiency Check
LAA: Local Airport Advisory
LAAS: Local Area Augmentation System
LAHSO: Land and Hold Short Operations
LDA: Localizer Type Directional Aid
LIRL: Low Intensity Runway Lights
LLWS: Low-Level Wind Shear
LLWAS: Low Level Wind Shear Alert System
LNAV: Lateral Navigation
LOC: Localizer
LPV: Localizer Performance with Vertical Guidance
LSA: Light Sport Aircraft
MAHWP: Missed Approach Holding Waypoint
MAP: Missed Approach Point
MAWP: Missed Approach Waypoint
MDA: Minimum Descent Altitude
MEA: Minimum En Route Altitude
METAR: Aviation Routine Weather Report
MIRL: Medium Intensity Runway Lights
MOA: Military Operations Area
MOCA: Minimum Obstruction Clearance Altitude
MRA: Minimum Reception Altitude
MSA: Minimum Safe Altitude
MSL: Mean Sea Level
MTOW: Maximum Takeoff Weight
MTR: Military Training Route
NAS: National Airspace System
NDB: Nondirectional Radio Beacon
NOTAM: Notice to Airmen
NM: Nautical Mile
NSA: National Security Area
PAPI: Precision Approach Path Indicator
PAR: Precision Approach Radar
PIREP: Pilot Report
RA: Resolution Advisory
RAIM: Receiver Autonomous Integrity Monitoring
REIL: Runway End Identifier Lights
RMI: Radio Magnetic Indicator
RNAV: Area Navigation
RNP: Required Navigation Performance
RVR: Runway Visual Range
RVSM: Reduced Visual Separation Minimums
SID: Standard Instrument Departure
SM: Statute Mile
SOP: Standard Operating Procedure
STAR: Standard Terminal Arrival Procedure
TAA: Technologically Advanced Aircraft
TAA: Terminal Arrival Area
TAF: Terminal Aerodrome Forecast
TAS: True Airspeed
TCAS: Traffic Alert and Collision Avoidance System
TDWR: Terminal Doppler Weather Radar
TDZE: Touchdown Zone Elevation
TFR: Temporary Flight Restriction
TIS: Traffic Information Service
TIS-B: Traffic Information Service Broadcast
TOLD: Takeoff and Landing Data
TRSA: Terminal Radar Service Area
VASI: Visual Approach Slope Indicator
VDP: Visual Descent Point
VFR: Visual Flight Rules
VMC: Visual Meteorological Conditions
VOR: Very-High Omni-Range Frequency
VORTAC: VOR with Tactical Air Navigation
VOT: VOR Test Facility
WAAS: Wide-Area Augmentation System
