ABBR,MEANING
3P,"Perceive, Process, Perform"
5P,"Plan, Plane, Pilot, Passengers, Programming"
7500,"Transponder code for Aircraft hijacking (ICAO)"
7600,"Transponder code for Radio failure (lost communications, ICAO)"
7700,"Transponder code for Emergency (ICAO)"
A/A,Air to air TACAN function
A/C,Aircraft
A/D,Aerodrome
A/F,Autofeather
A/FD,Airport/Facility Directory
A/P,Autopilot
A/R,Altitude Rate
A-VDGS,Advanced Visual Docking Guidance System
A300,Airbus A300 twinjet
A310,Airbus A310 twinjet
A320,Airbus A320 family of twinjets
A330,Airbus A330 twinjet
A340,Airbus A340 quadjet
A350,Airbus A350 twinjet
A380,Airbus A380 quadjet
AAA,Airport Airspace Analysis
AAE,Above Aerodrome Elevation
AAF,Airway Facilities Service
AAF,Army Air Field
AAI,Arrival Aircraft Interval
AAI,Airports Authority of India
AAIB,Air Accidents Investigation Branch (UK)
AAIM,Aircraft Autonomous Integrity Monitoring
AAM,Advanced Air Mobility
AAMS,Aircraft Arrival Management System
AARTS,Army Aviation Radar Training System
AAO,Assumed Adverse Obstacle
AAS,Airport Advisory Service
AB,"Air Base, Afterburner"
ABI,Advanced Boundary Information
AC,Aircraft
ACAC,Arab Civil Aviation Conference
ACAM,Aircraft Continuing Airworthiness Monitoring
ACARS,Aircraft Communications Addressing and Reporting System
ACAS,Airborne Collision Avoidance System
ACC,Area Control Center
ACE,Airport airside Capacity Enhancement
ACI,Airports Council International
ACP,Accept
AD,Air Defence
ADAC,Abu Dhabi Airports
ADEP,Aerodrome of Departure
ADES,Aerodrome of Destination
ADF,Automatic Direction Finding
ADI,Automatic De-Ice and Inhibitor
ADIRS,Air Data and Inertial Reference System
ADIRU,Air Data Inertial Reference Unit
ADIZ,Air Defense Identification Zone
ADL,Aeronautical Data Link
ADLY,Arrival Delay
ADP,Aerodrome dé Paris (Charles de Gaulle)
ADP,Automated Data Processing
ADS,"Automated Distribution System, Automatic Dependent Surveillance, Aircraft Docking System"
ADS-B,Automatic Dependent Surveillance-Broadcast
AENA,Aeropuertos Españoles y Navegación Aérea
AEO,All Engines Operative
AERA,Automated En-Route Air Traffic Control
AEW,Airborne Early Warning
AF,Air Field
AFCS,Automatic Flight Control System
AFI,Air Force Instruction
AFIS,Aerodrome Flight Information Service
AFTN,Aeronautical Fixed Telecommunication Network
AFM,Aircraft Flight Manual
AGAS,Action Group for ATM Safety (EUROCONTROL)
AGL,Above Ground Level
AGNIS,"Azimuth Guidance for Nose-In Stand (docking system)"
AH,Acceleration Height
ahdg,alter heading
AICS,Aircraft Inventory and Charter System
AID,Airport Information Desk
AIDS,Aircraft Integrated Data System
AIG,Airbus Industries Group
AILS,Automatic Instrument Landing System
AIM,Aeronautical Information Manual
AIP,Aeronautical Information Publication
AIPA,Aeronautical Information Production Application
AIRAC,Aeronautical Information Regulation And Control
AIRMET,Airmen's Meteorological Information
AIRNAV,Airports and Navigation Aids Database System
AIRNET,Airport Network Simulation Model
AIRPAC,Advisor for the Intelligent Resolution of Predicted Aircraft
ALO,Aviation Logistics Organization
ALP,Airport Layout Plan
ALPA,Airlines Pilots Association
ALS,Approach Lighting System
ALSF,Approach Lighting System With Sequenced Flashing Lights
ALSF1,ALS with Sequenced Flashers I
ALSF2,ALS with Sequenced Flashers II
ALSIP,Approach Lighting System Improvement Plan
ALTRV,Altitude Reservation
AM,Airfield Management
AMAN,Arrival Manager
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
AMOC,Alternative Methods of Compliance
AMOS,Automated Meteorological Observation Station
AMP,ARINC Message Processor (OR) Airport Master Plan
AMS,Acquisition Management System
AMT,Aviation Maintenance Technician
AMVER,Automated Mutual Assistance Vessel Rescue System
ANA,Administration of Air Navigation
ANC,Alternate Network Connectivity
ANCA,Airport Noise and Capacity Act
ANG,Air National Guard
ANGB,Air National Guard Base
ANMS,Automated Network Monitoring System
ANSL,Air Navigation Solutions Ltd. (UK)
ANSP,Air Navigation Service Provider
AOA,"Angle of Attack, Air Operations Area, Airport Operating Area"
AOB,Airfield Operations Board
AOC,Airline Operational Control Center
AOCC,Atlantic Operations Control Center
AODR,Authorizing Official Designated Representative
AOM,Airplane Operating Manual
AOPA,Aircraft Owners and Pilots Association
AOR,Area of Responsibility
AP,Acquisition Plan
APB,Acquisition Program Baselines
APIS,Aircraft Parking and Information System
APM,Approach Path Monitor
APP,Approach
APS,Airport Planning Standard
APTS,Automated Personnel Tracking System
APU,Auxiliary Power Unit
AQAFO,Aeronautical Quality Assurance Field Office
AR,Aerial Refueling
AR,Aspect Ratio
ARAC,Army Radar Approach Control (AAF)
ARFOR,Area Forecast
ARINC,Aeronautical Radio, Inc. (USA)
ARLNO,Airline Office
ARP,Airport Reference Point
ARTCC,Air Route Traffic Control Centre
ASB,Airspace Block
ASDA,Accelerate Stop Distance Available
ASDE,Airport Surface Detection Equipment
ASDE-X,"Airport Surface Detection Equipment, model X"
ASOS,Automated Surface Observation System
ASR,Airport Surveillance Radar
ASTERIX,All Purpose Structured Eurocontrol Surveillance Information Exchange
ATA,Actual Time of Arrival
ATC,Air Traffic Control
ATCALS,Air Traffic Control and Landing Systems
ATCO,Air Traffic Control Officer
ATIS,Automatic Terminal Information Service
ATM,"Air Traffic Management, Air Traffic Manager"
ATO,Air Traffic Organization
ATPL,Airline Transport Pilot License
AURO,Autorotation (by helicopters)
AWACS,Airborne Warning And Control System
BC,Back Course
BAF,Belgian Air Force
BASH,Bird/Wildlife Aircraft Strike Hazard
BDOC,Base Defense Operations Center
BIRTAM,NOTAM on Bird Activity
BIT,Build-In Test
BITE,Build-In Test Equipment
BRNAV,Basic Area Navigation
BWB,Blended Wing Body
BWC,Bird Watch Condition
C2,Command and Control
C3,"Communication, Command and Control"
C4I,"Communication, Command, Control, Computers and Intelligence"
CAAC,Civil Aviation Administration of China
CAAS,Civil Aviation Authorization of Singapore
CAL,Computer Assisted Learning
CAMACA,Common Agreed Methodology for Airport airside Capacity Assessment
CANAC,Computer Assisted National Air Traffic Control Centre (Belgium)
CANSO,Civil Air Navigation Services Organization
CARMA,CATC Radar Simulator Allahabad
CAS,Calibrated Airspeed
CASE,Controlled Airspace Synthetic Environment (Simulator of Alenia Marconi)
CAT,"Category of Aircraft, Clear Air Turbulence"
CATC,Civil Air Traffic Control
CAVOK,Clouds And Visibility OK
C/S,Callsign
CBT,Computer-based Training
CC,Commander
CCBC,Community College Baltimore County
CCIS,Closed Circuit Information System
CCTLR,Chief Controller
CDA,Continuous Descent Approach
CDI,Course Deviation Indicator
CDM,Collaborative Decision Making
CDTI,Cockpit Display of Traffic Information
CDU,Cockpit Display Unit
CEATS,Central European Air Traffic Services
CESC,Chief Executive Standing Conference
CFIT,Controlled Flight Into Terrain
CFMU,Central Flow Management Unit
CFR,Code of Federal Regulations
COG,Center of Gravity
CON,Control
CGD,Combined Graphic Display
CISM,Critical Incident Stress Management
CLC,Course Line Computer
CLNC,Clearance
CMA,Controlled Movement Area
CMIC,Civil/Military Interface Standing Committee
CNS,"Communication, Navigation, Surveillance"
CODA,Central Office for Delay Analysis
ConOps,Concept of Operations
COPS,Changeover Point(s)
CORA,Conflict Resolution Advisory
COTS,Commercial Of-The-Shelf
CPA,Closest Point of Approach
CPDLC,Controller Pilot Data Link Communication
CPI,Crash Position Indicator
CPL,Commercial Pilot License
CRC,Control and Reporting Centre
CRDA,Converging Runway Display Aid
CREDOS,Crosswind Reduced Separations for Departure Operations
CTA,"Controlled Area, Controlled Time of Arrival"
CTAF,Common Traffic Advisory Frequency
CTOT,Calculated Take-Off Time
CTR,Control Zone or Controlled Traffic Region
CV,Vice Commander
CVFR,Controlled Visual Flight Rule (flight)
CVSM,Conventional Vertical Separation Minimum
CW,Continous Wave
CW,Cold Weather
CWS,Collision Warning System
CWP,Controller Working Position
CWY,Clearway
DA,Density Altitude
DAS,DFS Aviation Services (DFS subcompany for services outside Germany)
DCIA,Dependent Converging Instrument Approach
DECIDE,"Detect, Estimate, Choose, Identify, Do, and Evaluate"
DEL,Delivery
DER,Departure End of Runway
DFS,Deutsche Flugsicherung (ATC in Germany)
DGAC,Direction Générale de l'Aviation Civile
DLA,Defense Logistics Agency
DP,Departure Procedure
DSNA,Direction des Services de la Navigation Aérienne 
DTI,Direction Technique Innovation
DVA,Diverse Vector Area
DW,Downwind
EAS,Equivalent Airspeed
EAVA,Estonian Aviation Academy
ECAC,European Civil Aviation Conference
eCTOL,Electric Conventional Take-off and Landing
ECP,Entry Control Point
EFM,Gesellschaft für Enteisen und Flugzeugschleppen
EICAS,Engine Instrument Crew Alerting System
ELEV,Field Elevation
ELT,Emergency Locator Transmitter
EOL,Engine-off landing
ERPM,Engine Rotations per Minute
eSTOL,Electric Short Take-off and Landing
ETA,"Estimated Time of Arrival, East Transition Area"
ETL,Effective Translational Lift (for helicopters)
ETOPS,Extended-range Twin-engine Operational Performance Standards
ETVS,Electronic Terminal Voice Switch
eVTOL,Electric Vertical Take-off and Landing
FAA,U.S. Federal Aviation Administration
FAR,"Fuel Air Ratio, Federal Aviation Regulations"
FAS,Final Approach Segment
FAS,Final Approach Speed
FAST,Future Aviation Safety Team
FAT,Factory Acceptance Test (see also SAT and RAT)
FAT,Final Approach Track
FATO,Final Approach and Take-off Area
FAWP,Final Approach Waypoint
FAWS,Flight Advisory Weather Service
FBO,Fixed-Base Operator
FBW,Fly-by-Wire
FCA,Final Cruise Altitude
FCC,Federal Communications Commission (USA)
FCC,Flight Control Computer
FCI,Flight Command Indicator
FCL,Flight Crew Licensing
FCLP,Field Carrier Landing Practice
FCLT,Freeze Calculated Landing Time
FCLTP,Flight Crew Licensing and Training Panel (ICAO)
FCOM,Flight Crew Operating Manual
FCOM,Flight Crew Operations Manual
FCPC,Flight Control Primary Computer
FE,Field Elevation (highest point of an airport’s usable runways and is measured in height above mean sea level)
FIA,Flight Information Area
FIR,Flight Information Region
FIS,Federal Inspection Services
FL,Flight Level
FLIP,Flight Information Publication
FMG,Flughafen München GmbH
FMS,Flight Management System
FOD,Foreign Object Debris
FOV,Field of View
FWC,Flight Warning Computer
GA,"General Aviation, Go Around (VFR)"
GND,Ground
GP,Glide Path
GPS,Global Positioning System
GS,Ground Speed or Glideslope
HEMS,Helicopter Emergency Medical Services
HKIA,Hong Kong International Airport
HOGE,Hover Out of Ground Effect
HOTS,Higher-Order Thinking Skills
IAA,Israeli Airport Authority
IAF,Israeli Air Force
IANS,Institute of Air Navigation Services, a division of Eurocontrol
IAS,Indicated airspeed
IATA,"International Air Transport Association, HQ in Montreal, Canada"
ICA,Initial Climb Area
IFE,In-flight Emergency
IFR,Instrument Flight Rules
IG,Image Generator
IGE,In Ground Effect
IGLR,Integrated Ground Lighting and Radar
ILS,Instrument Landing System
ISA,International Standard Atmosphere
IMC,Instrument Meteorological Conditions
KAT,Kaufbeuren ATM Training (DFS subcompany)
KCAS,Calibrated AirSpeed in Knots
KIAS,Indicated Airspeed in Knots
KTAS,True AirSpeed in Knots
LAA,Lappland Aviation Academy
LDA,Landing Distance Available
LDAH,Landing Distance Available for Helicopter
LH,Lufthansa
LITAS,Low Intensity Two Colour Approach System 
LL,Lower Limit
LMUK,Lockheed Martin UK
LOD,Level of Detail
LTA,Lower Traffic Area
LUAW,Line up and wait
LVNL,Luchtverkeersleiding Nederland (Air Traffic Control the Netherlands)
LVP,Low Visibility Procedures
LWINS,Lightweight Inertial Navigation System
MA,Missed Approach (IFR)
MATS,Malta Air Traffic Services
MEA,Minimum En-route Altitude
METAR,Meteorological Aerodrome Report
MCP,Maximum Continuous Power
MGTOW,Maximum Gross Take-off Weight
MLW,Maximum Landing Weight
MMR,Multi-Mode Receiver
MSA,Minimum Safe Altitude
MSL,Median Sea Level
MSTA,Minimum Safe Turning Altitude
MTOW,Maximum Take-Off Weight
NATCA,National Air Traffic Controllers Association
NATOPS,Naval Aviation Training and Operating Procedures Standardization
NATS,National Air Traffic Services (UK)
NAVAIDS,Navigational Aids
NCOIC,Non-Commissioned Officer in Charge
NIMA,National Imagery Mapping Agency
NLFS,Night Low Flying System
NM,Nautical Mile
NORDO,No Radio
NOTAM,Notice to Airmen or Notice to Air Missions
NUAIR,Northeast UAS Airspace Integration Research (a New York based nonprofit organization)
OCS,Obstacle Clearance Surfaces
OCTA,Outside Control Areas
OEI,One Engine Inoperative
ODP,Obstacle Departure Procedure
OGE,Out of Ground Effect
OFZ,Obstacle Free Zone
OJT,On the Job Training
OODA,"Observation, Orientation, Decision, and Action"
PA,Pressure Altitude
PADS,Parallax Aircraft Docking System
PAPA,"Parallax Aircraft Parking Aid (docking system)"
PAPI,Precision Approach Path Indicator
PAR,Precision Approach Radar
PCAS,Primary Crash Alarm System
PIC,Pilot in Command
PNF,Pilot Not Flying 
POH,Pilot's Operating Handbook
PPL,Private Pilot's License
PMI,Preventative Maintenance Inspection
POFZ,Precision Obstacle Free Zone
PTAC,"Position, Turn, Altitude, Clearance (also known as Approach Clearance)"
PtF,Permit to Fly
QFE,"the altimeter setting that will cause the altimeter to read the height above a specific aerodrome or ground level, and therefore read zero on landing"
QNE,pressure altitude at the landing runway threshold
QNH,atmospheric pressure adjusted to mean sea level
RADAR,Radio Detection And Ranging
RADNET,Radar Network
RAIM,Receiver Autonomous Integrity Monitoring (GPS)
RAPCON,Radar Approach Control
RAT,Reliability Acceptance Test (see also FAT and SAT)
RAM,Royal Air Maroc
RAP,Recognised Air Picture
RASP,Recognised Air and Surveillance Picture
RB,Relative Bearing
RBI,Relative Bearing Indicator
RBAF,Royal Belgium Armed Forces
RCAF,Royal Canadian Air Force
RCC,Rescue Co-ordination Centre
RCL,Runway Centre Line Lighting
RCR,Runway Condition Reading
RCS,Radar Cross Section
RESA,Runway End Safety Area
RET,Rapid Exit Taxiways
RF,Radio Frequency
RFFS,Rescue and Fire Fighting Services
RFM,Rotorcraft Flight Manual
RIMCAS,Runway Incursion Monitoring and Conflict Alert System
RJAF,Royal Jordanian Air Force
RJC,Reject
RPI,Runway Point of Intercept
ROFZ,Runway Obstacle Free Zone
RMI,Radio Magnetic Indicator
RNAV,Area Navigation
RNP,Required Navigation Performance
ROC,Rate Of Climb
ROC,Required Obstacle Clearance
RPS,Radar Position Symbol
RRPM,Rotor Rotations per Minute
RSA,Runway Safety Area
RSAF,Republic of Singapore Air Force
RSC,Runway Surface Condition
RSI,Remote Status Indicato
RSRS,Reduced Same Runway Separation
RTCA,Radio Technical Commission for Aeronautics
RVR,Runway Visual Range
RVSM,Reduced Vertical Separation Minimum
RWR,Radar Warning Receiver
RWY,Runway
SADL,Situational Awareness Data Link
SAF,Sustainable Aviation Fuel
SAR,"Search and Rescue, Synthetic Aperture Radar"
SARPS,Standards and Recommended Practices (ICAO)
SAT,Site Acceptance Test (see also FAT and RAT)
SATCO,Senior Air Traffic Control Officer
SATCOM,Satellite Communication
SATNAV,Satellite Navigation
SATSE,State Air Traffic Services Enterprise
SCN,Secondary Crash Net
SDD,Situation Data Display
SEOL,Simulated engine-off landing
SELCAL,Selective Calling System
SES,Single European Sky
SESAME,Single European Sky ATM Master Plan
SESAR,Single European Sky ATM Research
SFL,Sequencing Flashing Light
SFO,Simulated Flameout Operation
SI,Selective Interrogation
SIAP,Standard Instrument Approach Procedure
SID,Standard Instrument Departure
SIF,Selective Identification Friend or Foe
SIGMET,Significant Meteorological (Information) Report
SILs,Sector Inbound Lists
SIM,Simulator
SKYGUIDE,Air Traffic Control of Switzerland
SL,Sea Level
SLB,Side lobe Blanking
SLC,Side lobe Cancellation
SLOC,Slovenia Control
SM,Statute Mile
SMR,Surface Movement Radar
SOF,Supervisor of Flying
SOW,Statement of Work
SRC,Safety Regulation Commission (EUROCONTROL)
SRU,Safety Regulation Unit (EUROCONTROL)
SSR,Secondary Surveillance Radar
STAR,Standard Arrival Route or Standard Terminal Arrival Route
STARS,Standard Terminal Automation Replacement System
STB,Stop Bar
STCA,Short Term Conflict Alert
STD,Synthetic Training Device
STDMA,Self-organising Time Division Multiple Access (known as VHF digital link - Mode 4)
STNA,Service Technique de la Navigation Aerienne
STO,Short Take-Off
STOVL,Short Take-Off and Vertical Landing
STOL,Short Take-Off and Landing
STRATFOR,Eurocontrol Statistics and Forecasts Service
SUA,Special Use Airspace
SV,Supervisor
SVFR,Special Visual Flight Rules
SWT,Switch
SWY,Stopway
SYSCO,System Coordination – Data Exchange and Coordination
TA,Terminal Airspace
TAA,Terminal Arrival Area
TAAM,Total Airspace and Airport Modeller
TACAN,Tactical Air Navigation (System)
TACS,Theater Air Control System
TACTICOS,Tactical Information and Command System
TAF,Terminal Aerodrome/Area Forecast
TAIS,Tactical Airspace Integration System (US Army)
TAIS,Tactical Air Intelligence System
TAP,Target Acquisition Protocol
TARMAC,Taxi and Ramp Management and Control
TAS,Terminal Airspace System
TAS,True Air Speed
TAWS,Terrain Avoidance and Warning System
TCAS,Traffic alert and Collision Avoidance System
TCDS,Type Certificate Data Sheet
TCH,Threshold Crossing Height
TCL,Thrust Control Lever or Taxi Center Lights 
TDW,Tower Display Workstation
TDZ,Runway Touchdown Zone Lighting
TDZE,Touch Down Zone Elevation
TERPS,US Standard for Terminal Instrument Procedures
TFDM,Terminal Flight Data Management
TFDPS,Tower Flight Data Processing System
TFM,Traffic Flow Management
TFR,Temporary Flight Restriction
TH,True Heading
TID,Touch Input Device
TIS,Traffic Information System
TLOF,Touchdown and Lift-off Area
TM,Traffic Management
TMA,Terminal Control Area
TOC,Top Of Climb
TOD,Top Of Descent
TODA,Take-off Distance Available
TODAH,Take-off Distance Available for Helicopter
TOP,Take-Off Power
TOR,"Terms of Reference, or Tornado aircraft"
TORA,Takeoff Run Available
TOWSIM,Tower Simulator
TRACON,Terminal Radar Approach Control
TRH,Thrust Reduction Height
TSO,Technical Standard Order
TSTC,Texas State Technical College
TT,True Track
TVOR,Terminal VOR
TWEB,Transcribed Weather Broadcast (USA for ATIS)
TWR,Control Tower or Thrust to Weight Ratio
TWY,Taxiway
TXC,Taxiway Centreline Lights
TXE,Taxiway Edge Lights
UA,Unmanned Aircraft
UAC,Upper Area Control Centre
UAM,Urban Air Mobility
UAS,Unmanned Aircraft Systems
UAT,Universal Access Transceiver
UAV,Unmanned Aerial Vehicle
UCAV,Unmanned Combat Aerial Vehicle
UDF,Ultra High Frequency Direction Finding
UEI,"Units, Equipment, Installations"
UFA,"UFA, Inc., the world's premier developer of Air Traffic Control simulation systems"
UHF,Ultra High Frequency (300MHz to 3 GHz)
UIR,Upper Flight Information Region
UKCAA,United Kingdom Civil Aviation Authority
UMASS,University of Massachusetts
URET,User Request Evaluation Tool
USAF,United States Air Force
UTA,Upper Traffic Area
V1,Decision speed, the speed beyond which takeoff should no longer be aborted
V2,Takeoff speed. The speed at which the aircraft may safely be climbed with one engine inoperative
VAR,Magnetic Variation
VASI,Visual Approach Slope Indicator
VASIS,Visual Approach Slope Indicator System 
VCS,Voice Communication System
VCCS,Voice Communication Control System
VCOA,Visual Climb Over Airport
VDF,Very High Frequency Direction Finding
VDGS,"Visual Docking Guidance System, Visual Database Generation System"
VDL-4,VHF digital link Mode 4 (see also STDMA)
VDU,Visual Display Unit
VFS,Vertical Flight Society
VFOW,Vertical Field of View
VFR,Visual Flight Rules
VHF,Very High Frequency (3 to 300MHz)
VLF,Very Low Frequency
VMC,Visual Meteorological Conditions
VMO,maximum operation speed is the air speed than should never be exceeded deliberately in normal operation, whatever the flight situation isVOR,VHF Omni-directional Range
VOLMET,Meteorological Information for Aircraft in Flight
VOR,VHF Omni-directional Receiver
VORTAC,VOR -TACAN combination
VREF,1.3 times the stalling speed of the aircraft in the stated landing configuration and at the prevailing aircraft weight
VRS,Vortex Ring State
VS,"Stall speed, defined as the minimum steady flight speed at which the airplane is controllable"
VSBY,Visibility
VSP,Vertical Speed
VSTOL,Vertical Short Take-Off and Landing
VTC,Visual Terminal Chart
VTC,Virtual Training Centre
VTOL,Vertical Take-Off and Landing
VTOSL,Vertical Take-Off and Short Landing
VTS,Vehicle Tracking System
Vtoss,Take-off safety speed
Vy,Optimimum climbing speed
Vz,Rate-of-climb
WA,Wind Angle
WAAS,Wide Area Augmentation System
WAM,Wide Area Multilateration
WBS,Work Break-down Structure
WCA,Wind Correction Angle
WDI,Wind Direction Indicator
WGS,World Geodetic System
WIAS,Wetter Informations- und Anzeigesystem (German)
WP,Waypoint
WS,Work Station
WTC,Wake Turbulence Category
WTWS,Wake Turbulence Warning System
WX,Weather
WXR,Weather Radar Transceiver