Note * Not ICAO Abbreviation
| A | |
| AAHK | Airport Authority Hong Kong* |
| AAL | Above aerodrome level |
| ABM | Abeam |
| AC | Altocumulus |
| ACAS | Airborne collision avoidance system |
| ACC | Area control centre or area control |
| ACFT | Aircraft |
| ACL | Altimeter check location |
| AD | Aerodrome |
| ADF | Automatic direction-finding equipment |
| ADS-B | Automatic dependent surveillance – broadcast |
| ADS-C | Automatic dependent surveillance – contract |
| AFIL | Flight plan filed in the air |
| AFM | Yes or affirm or affirmative or that is correct |
| AFS | Aeronautical fixed service |
| AFTN | Aeronautical fixed telecommunication network |
| AGA | Aerodromes, air routes and ground aids |
| AGL | Above ground level |
| AIC | Aeronautical information circular |
| AIMC | Aeronautical Information Management Centre* |
| AIP | Aeronautical information publication |
| AIRAC | Aeronautical information regulation and control |
| AIREP | Air-report |
| AIS | Aeronautical information services |
| ALERFA | Alert phase |
| ALR | Alerting (message type designator) |
| ALRS | Alerting service |
| ALS | Approach lighting system |
| ALT | Altitude |
| ALTN | Alternate (aerodrome) |
| AMD | Amend or amended (used to indicate amended meteorological message; message type designator) |
| AMDT | Amendment (AIP amendment) |
| AMS | Aeronautical mobile service |
| AMSL | Above mean sea level |
| AMSS | Aeronautical mobile satellite service |
| AOC | Aerodrome obstacle chart (followed by type and name/title) |
| AOM | Aerodrome Operating Minima* |
| AOR | Area of Responsibility* |
| AP | Airport |
| APCH | Approach |
| APP | Approach control office or approach control or approach control service |
| APR | April |
| APRX | Approximate or approximately |
| ARFOR | Area forecast (in aeronautical meteorological code)* |
| ARP | Aerodrome reference point |
| ARP | Air-report (message type designator) |
| AS | Altostratus |
| ASC | Ascend to or ascending to |
| ASDA | Accelerate-stop distance available |
| ASPH | Asphalt |
| ASR | Approach surveillance radar* |
| ASSR | Approach secondary surveillance radar* |
| AT | At (followed by time at which weather change is forecast to occur) |
| ATA | Actual time of arrival |
| ATC | Air traffic control (in general) |
| ATCC | Air traffic control centre* |
| ATCU | Air traffic control unit* |
| ATD | Actual time of departure |
| ATFM | Air traffic flow management |
| ATIS | Automatic terminal information service |
| ATM | Air traffic management |
| ATN | Aeronautical telecommunication network |
| ATS | Air traffic services |
| ATTN | Attention |
| ATZ | Aerodrome traffic zone |
| AUG | August |
| AUTH | Authorized or authorization |
| AUW | All up weight |
| AUX | Auxiliary |
| AVBL | Available or availability |
| AVGAS | Aviation gasoline |
| AVTUR | Aviation turbine fuel* |
| AWY | Airway |
| AZM | Azimuth |
| B | |
| BASE | Cloud base |
| BCFG | Fog patches |
| BCN | Beacon (aeronautical ground light) |
| BCST | Broadcast |
| BDRY | Boundary |
| BECMG | Becoming |
| BFR | Before |
| BKN | Broken |
| BLDG | Building |
| BLW | Below..... |
| BR | Mist |
| BRF | Short (used to indicate the type of approach desired or required) |
| BRG | Bearing |
| BRKG | Braking |
| BTN | Between |
| C | |
| C | Centre (preceded by runway designation number to identify a parallel runway) |
| C | Degrees Celsius (Centigrade) |
| CAD | Civil Aviation Department* |
| CASEVAC | Casualty evacuation* |
| CAT | Category |
| CAT | Clear air turbulence |
| CAVOK | Visibility, cloud and present weather better than prescribed values or conditions |
| CB | Cumulonimbus |
| CC | Cirrocumulus |
| CCA | (or CCB, CCC...etc., in sequence) Corrected meteorological message (message type designator) |
| CCTV | Closed circuit television* |
| CDC | Clearance delivery control* |
| CDN | Co-ordination (message type designator) |
| CH | Channel |
| CHG | Modification (message type designator) |
| CI | Cirrus |
| CIDIN | Common ICAO data interchange network |
| CL | Centre line |
| CLA | Clear type of ice formation |
| CLBR | Calibration |
| CLD | Cloud |
| CLG | Calling |
| CLIMB-OUT | Climb-out area |
| CLR | Clear(s) or cleared to... or clearance |
| CLRD | Runway/s cleared (in METAR/SPECI) |
| CLSD | Close or closed or closing |
| CM | Centimetre |
| CNL | Cancel or cancelled |
| CNL | Flight plan cancellation (message type designator) |
| CNS | Communications, navigation and surveillance |
| COM | Communications |
| CONC | Concrete |
| COND | Condition |
| CONST | Construction or constructed |
| CONT | Continue(s) or continued |
| COOR | Co-ordination |
| COP | Change-over point |
| COR | Correct or correction or corrected (used to indicate corrected meteorological message; message type designator) |
| CPL | Current flight plan (message type designator) |
| CS | Cirrostratus |
| CTA | Control area |
| CTC | Contact |
| CTL | Control |
| CTN | Caution |
| CTR | Control zone |
| CU | Cumulus |
| CUF | Cumuliform |
| CUST | Customs |
| CVSM | Conventional separation minima* |
| CWY | Clearway |
| D | |
| D | Danger area (followed by identification) |
| D | Distance* |
| DA | Decision altitude |
| DCD | Double channel duplex |
| DCP | Datum crossing point |
| DCS | Double channel simplex |
| DCT | Direct (in relation to flight plan clearances and type of approach) |
| DEC | December |
| DEG | Degrees |
| DEP | Departure (message type designator) |
| DER | Departure end of runway |
| DES | Descend to or descending to |
| DEST | Destination |
| DETRESFA | Distress phase |
| DFTI | Distance from touchdown indicator |
| DH | Decision height |
| DIAM | Diameter* |
| DIST | Distance |
| DIV | Divert or diverting |
| DLA | Delay (message type designator) |
| DME | Distance measuring equipment |
| DOF | Date of flight |
| DP | Dew point temperature |
| DR | Dead reckoning |
| DRG | During |
| DS | Dust storm |
| DTG | Date-time group |
| DU | Dust |
| DUC | Dense upper cloud |
| DUR | Duration |
| DVOR | Doppler VOR |
| DZ | Drizzle |
| E | |
| E | East or eastern longitude |
| EAT | Expected approach time |
| EDA | Elevation differential area |
| EET | Estimated elapsed time |
| EGNOS | European geostationary navigation overlay service |
| ELEV | Elevation |
| ELR | Extra long range |
| EM | Emission |
| EMBD | Embedded in layer (to indicate cumulo nimbus embedded in layers of other clouds) |
| EMERG | Emergency |
| EN | English* |
| END | Stop-end (related to RVR) |
| ENE | East north east |
| ENG | Engine |
| ENR | En-route |
| EOBT | Estimated off-block time |
| EQPT | Equipment |
| ESE | East south east |
| EST | Estimate or estimated or estimate (message type designator) |
| ETA | Estimate time of arrival or estimating arrival |
| ETD | Estimated time of departure or estimating departure |
| ETO | Estimated time over significant point |
| F | |
| FAC | Facilities |
| FAF | Final approach fix |
| FAL | Facilitation of international air transport |
| FAP | Final approach point |
| FATO | Final approach and take off area |
| FAX | Facsimile transmission |
| FBL | Light (used to indicate the intensity of weather phenomena, interference or static reports, eg FBL RA = light rain) |
| FC | Funnel cloud (tornado or water spout) |
| FCST | Forecast |
| FCT | Friction coefficient |
| FEB | February |
| FG | Fog |
| FIC | Flight information centre |
| FIR | Flight information region |
| FIS | Flight information service |
| FL | Flight level |
| FLG | Flashing |
| FLR | Flares |
| FLT | Flight |
| FLTCK | Flight check |
| FLW | Follow(s) or following |
| FM | From (followed by time weather change is forecast to begin) |
| FNA | Final approach |
| FPAP | Flight path alignment point |
| FPL | Filed flight plan exchanged via aeronautical fixed service (AFS) |
| FPM | Feet per minute |
| FREQ | Frequency |
| FRI | Friday |
| FRNG | Firing |
| FRONT | Front (relating to weather) |
| FRQ | Frequent |
| FST | First |
| FT | Feet (dimensional unit) |
| FU | Smoke |
| FZ | Freezing |
| FZDZ | Freezing drizzle |
| FZFG | Freezing fog |
| FZRA | Freezing rain |
| G | |
| G | Variations from the mean wind speed (gusts)(followed by figures in METAR/SPECI and TAF) |
| G/A | Ground-to-air |
| GA | General Aviation |
| GAGAN | GPS and Geostationary earth orbit augmented navigation |
| GARP | GBAS azimuth reference point |
| GBAS | Ground-based augmentation system |
| GEN | General |
| GEO | Geographic or true |
| GFS | Government Flying Service* |
| GMC | Ground movement control* |
| GND | Ground |
| GNDCK | Ground check |
| GNSS | Global navigation satellite system |
| GP | Glide path |
| GPS | Global positioning system |
| GR | Hail |
| GRAS | Ground-based regional augmentation system |
| GS | Ground speed |
| H | |
| H24 | Continuous day and night service |
| HBN | Hazard beacon |
| HDG | Heading |
| HEL | Helicopter |
| HF | High frequency (3 000 to 30 000 kHz) |
| HGT | Height or height above |
| HJ | Sunrise to sunset |
| HK | Hong Kong* |
| HKD | Hong Kong Dollars* |
| HKIA | Hong Kong International Airport* |
| HLDG | Holding |
| HN | Sunset to sunrise |
| HO | Service available to meet operational requirements |
| HOL | Holiday |
| HPA | Hectopascal |
| HR | Hours |
| HS | Service available during hours of scheduled operations |
| HVY | Heavy (used to indicate the intensity of weather phenomena, e.g. HVY RA = heavy rain) |
| HZ | Haze |
| HZ | Hertz (cycle per second) |
| I | |
| I/V | Instrument / visual* |
| IAC | Instrument approach chart |
| IAF | Initial approach fix |
| IAP | Instrument approach procedure |
| IAS | Indicated air speed |
| IASC | Inter-area speech circuit* |
| IBN | Identification beacon |
| IC | Illumination candles* |
| ICAO | International Civil Aviation Organization |
| ICE | Icing |
| ID | Identifier or identify |
| IDENT | Identification |
| IF | Intermediate approach fix |
| IFR | Instrument flight rules |
| ILS | Instrument landing system |
| IMC | Instrument meteorological conditions |
| IMG | Immigration |
| INA | Initial approach |
| INBD | Inbound |
| INCERFA | Uncertainty phase |
| INFO | Information |
| INOP | Inoperative |
| INPR | In progress |
| INS | Inertial navigation system |
| INSTL | Install or installed or installation |
| INSTR | Instrument |
| INT | Intersection |
| INTL | International |
| INTRG | Interrogator |
| INTRP | Interrupt or interruption or interrupted |
| INTSF | Intensify or intensifying |
| INTST | Intensity |
| IR | Ice on runway |
| ISA | International standard atmosphere |
| ISOL | Isolated |
| J | |
| JAN | January |
| JUL | July |
| JUN | June |
| K | |
| KG | Kilograms |
| KHZ | Kilohertz |
| KIAS | Knots indicated airspeed |
| KM | Kilometres |
| KT | Knots |
| KW | Kilowatts |
| L | |
| L | Left (preceded by runway designation number to identify a parallel runway) |
| LAM | Logical acknowledgement (message type designator) |
| LAT | Latitude |
| LCA | Local, locally, location or located |
| LDA | Landing distance available |
| LDG | Landing |
| LDI | Landing direction indicator |
| LGT | Light or lighting |
| LGTD | Lighted |
| LIH | Light intensity high |
| LIL | Light intensity low |
| LLZ | Localizer (progressively changed to LOC)* |
| LOC | Localizer |
| LONG | Longitude |
| LORAN | LORAN (long range air navigation system) |
| LRG | Long range |
| LTD | Limited |
| LTP | Landing threshold point |
| LV | Light and variable (relating to wind) |
| LVL | Level |
| LVP | Low visibility procedures |
| M | |
| M | Degree(s) magnetic* |
| M | Mach number (followed by figures) |
| M | Metres (preceded by figures) |
| M | Minimum value of runway visual range (followed by figures in METAR/SPECI) |
| MAINT | Maintenance |
| MAP | Aeronautical maps and charts |
| MAPT | Missed approach point |
| MAR | March |
| MAX | Maximum |
| MAY | May |
| MDA | Minimum descent altitude |
| MDH | Minimum descent height |
| MEA | Minimum en-route altitude |
| MEDEVAC | Medical evacuation flight |
| MEHT | Minimum eye height above threshold (for visual approach slope indicator systems) |
| MET | Meteorological or meteorology |
| METAR | Aerodrome routine meteorological report (in meteorological code) |
| MF | Medium frequency (300 to 3 000 kHz) |
| MHZ | Megahertz |
| MID | Mid-point (related to RVR) |
| MIFG | Shallow fog |
| MIL | Military |
| MIN | Minutes |
| MLS | Microwave landing system |
| MM | Middle marker |
| MMF | Middle marker fix* |
| MNM | Minimum |
| MNPS | Minimum navigation performance specifications |
| MNTN | Maintain |
| MOC | Minimum obstacle clearance (required) |
| MOD | Moderate (used to indicate the intensity of weather phenomena, interference or static reports, e.g. MOD RA = moderate rain) |
| MON | Monday |
| MOV | Move or moving or movement |
| MRA | Minimum reception altitude |
| MRG | Medium range |
| MRP | ATS/MET reporting point |
| MS | Minus |
| MSA | Minimum sector altitude |
| MSAS | Multi-functional satellite-based augmentation system |
| MSAW | Minimum safe altitude warning |
| MSG | Message |
| MSL | Mean sea level |
| MT | Mountain |
| MTW | Mountain waves |
| MX | Mixed type of ice information (white and clear) |
| N | |
| N | No distinct tendency (in RVR during previous 10 minutes) |
| N | North or northern latitude |
| NAV | Navigation |
| NAVAID | Navigation aid |
| NB | Northbound |
| NBFR | Not before |
| NC | No change |
| NCD | No cloud detected (In automated METAR/SPECI) |
| NDB | Non directional radio beacon |
| NDV | No directional variations available (in automated METAR/SPECI) |
| NE | North-east |
| NEB | North-eastbound |
| NEG | No or negative or permission not granted or that is not correct |
| NGT | Night |
| NIL | None or I have nothing to send |
| NM | Nautical miles |
| NML | Normal |
| NNE | North north east |
| NNW | North north west |
| NOF | International NOTAM office |
| NOSIG | No significant change (used in trend-type landing forecasts) |
| NOTAM | Notice distributed by means of telecommunication containing information concerning the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel concerned with flight operations |
| NOTAMC | Cancelling NOTAM |
| NOTAMN | New NOTAM |
| NOTAMR | Replacing NOTAM |
| NOV | November |
| NR | Number |
| NS | Nimbostratus |
| NSC | Nil significant cloud |
| NW | North-west |
| NXT | Next |
| O | |
| O/R | On request |
| OAC | Oceanic area control centre |
| OBS | Observe or observed or observation |
| OBSC | Obscure or obscured or obscuring |
| OBST | Obstacle |
| OCA | Obstacle clearance altitude |
| OCC | Occulting (light) |
| OCH | Obstacle clearance height |
| OCL | Obstacle clearance limit* |
| OCN | Oceanic control area* |
| OCNL | Occasional or occasionally |
| OCS | Obstacle clearance surface |
| OCT | October |
| OM | Outer marker |
| OMF | Outer marker fix* |
| OPMET | Operational meteorological (information) |
| OPN | Open or opening or opened |
| OPR | Operator or operate or operative or operating or operational |
| OPS | Operations |
| OVC | Overcast |
| P | |
| P | Maximum value of wind speed runway visual range (followed by figures in METAR/SPECI and TAF) |
| P | Prohibited area (followed by identification) |
| PA | Precision approach |
| PANS | Procedures for air navigation services |
| PAPI | Precision approach path indicator |
| PARA | Paragraph* |
| PAX | Passenger(s) |
| PBN | Performance-based navigation |
| PCN | Pavement classification number |
| PDC | Pre-departure clearance |
| PE | Ice pellets |
| PER | Performance |
| PERM | Permanent |
| PLVL | Present level |
| PN | Prior notice required |
| PNR | Point of no return |
| PO | Dust devils |
| POB | Persons on board |
| PPR | Prior permission required |
| PRI | Primary |
| PROB | Probability |
| PROC | Procedure |
| PS | Plus |
| PSN | Position |
| PWR | Power |
| Q | |
| QDM | Magnetic heading (zero wind) |
| QDR | Magnetic bearing |
| QFE | Atmospheric pressure at aerodrome elevation (or at runway threshold) |
| QFU | Magnetic orientation of runway |
| QNH | Altimeter sub-scale setting to obtain elevation when on the ground |
| QTE | True bearing |
| R | |
| R | Radial from VOR (followed by three figures) |
| R | Restricted area (followed by identification) |
| R | Right (preceded by runway designation number to identify a parallel runway) |
| RA | Rain |
| RAC | Rules of the air and air traffic services |
| RAD | Radar* |
| RASS | Remote altimeter setting source |
| RCC | Rescue co-ordination centre |
| RCF | Radio communication failure (message type designator) |
| RCL | Runway centre line |
| RCLL | Runway centre line light(s) |
| RDH | Reference datum height |
| RDO | Radio |
| RE | Recent (used to qualify weather phenomena, e.g. RERA = recent rain) |
| REC | Receive or receiver |
| REDL | Runway edge light(s) |
| REF | Reference to .. or refer to ... |
| REG | Registration |
| RENL | Runway end light(s) |
| REP | Report or reporting or reporting point |
| REQ | Request or requested |
| RESA | Runway end safety area |
| RETIL | Rapid Exit Taxiway Indicator Lights* |
| RLCE | Request level change en-route |
| RMAC | Radar minimum altitude chart* |
| RMK | Remark |
| RNAV | Area navigation |
| RNG | Radio range |
| RNP | Required navigation performance |
| ROC | Rate of climb |
| RPL | Repetitive flight plan |
| RQP | Request flight plan (message type designator) |
| RQS | Request supplementary flight plan (message type designator) |
| RRA | (or RRB, RRC ... etc., in sequence) Delayed meteorological message (message type designator) |
| RSR | En-route surveillance radar |
| RSSR | En-route secondary surveillance radar* |
| RTD | Delayed (used to indicate delayed meteorological message, message type designator) |
| RTE | Route |
| RTF | Radiotelephone |
| RVR | Runway visual range |
| RVSM | Reduced vertical separation minima |
| RWY | Runway |
| S | |
| S | South or southern latitude |
| SA | Sand |
| SAR | Search and rescue |
| SARPS | Standards and Recommended Practices (ICAO) |
| SAT | Saturday |
| SATCOM | Satellite communication (used only when referring generally to both voice and data satellite communication or only data satellite communication) |
| SB | Southbound |
| SBAS | Satellite-based augmentation system |
| SC | Stratocumulus |
| SCT | Scattered |
| SDBY | Stand by |
| SE | South-east |
| SEA | South East Asia* |
| SEB | South-eastbound |
| SEC | Seconds |
| SECT | Sector |
| SELCAL | Selective calling system |
| SEP | September |
| SER | Service or servicing or served |
| SEV | Severe (used e.g. to qualify icing and turbulence reports) |
| SFC | Surface |
| SG | Snow grains |
| SH | Showers (followed by RA=rain, SN=snow, PL=ice pellets, GR=hail, GS=small hail and/or snow pellets or combinations thereof, e.g. SHRASN = showers of rain and snow) |
| SID | Standard Instrument Departure |
| SIGMET | Information concerning en-route weather and other phenomena in the atmosphere that may affect the safety of aircraft operations |
| SIGWX | Significant weather* |
| SKARA | Shek Kong Aerodrome Reporting Area* |
| SKC | Sky clear* |
| SKED | Schedule or scheduled |
| SMR | Surface movement radar |
| SN | Snow |
| SNOWTAM | A special series NOTAM notifying the presence or removal of hazardous conditions due to snow, ice, slush and ice on the movement area, by means of a special format |
| SPECI | Aerodrome special meteorological report (in meteorological code) |
| SPECIAL | Special meteorological report (in abbreviated plain language) |
| SPL | Supplementary flight plan(message type designator) |
| SQ | Squall |
| SR | Sunrise |
| SRA | Surveillance radar approach |
| SRE | Surveillance radar element of precision approach radar system |
| SRY | Secondary |
| SS | Sandstorm |
| SS | Sunset |
| SSB | Single sideband |
| SSE | South south east |
| SSR | Secondary surveillance radar |
| SSW | South south west |
| ST | Stratus |
| STA | Straight in approach |
| STAR | Standard Instrument Arrival |
| STD | Standard |
| STF | Stratiform |
| STN | Station |
| STS | Status |
| STWL | Stopway light(s) |
| SUN | Sunday |
| SUP | Supplement (AIP Supplement) |
| SUPPS | Regional supplementary procedures |
| SVFR | Special visual flight rules* |
| SW | South-west |
| SWB | South-westbound |
| SWY | Stopway |
| T | |
| T | True (preceded by a bearing to indicate reference to True North) |
| TA | Transition altitude |
| TAA | Terminal arrival altitude |
| TAF | Aerodrome forecast |
| TAS | True airspeed |
| TC | Tropical cyclone |
| TCAS | Traffic alert and collision avoidance system* |
| TCAS RA | Traffic alert and collision avoidance system resolution advisory |
| TCH | Threshold crossing height* |
| TCU | Towering cumulus |
| TDWR | Terminal Doppler Weather Radar* |
| TDZ | Touchdown zone |
| TEL | Telephone |
| TEMP | Temperature* |
| TEMPO | Temporary or temporarily |
| TEND | Trend forecast* |
| TFC | Traffic |
| THR | Threshold |
| THRU | Through |
| THU | Thursday |
| TIL | Until |
| TL | Till (followed by time by which weather change is forecast to end) |
| TMA | Terminal control area |
| TN | Minimum temperature |
| TO | To ... (place) |
| TODA | Take-off distance available |
| TORA | Take-off run available |
| TR | Track |
| TRANS | Transmits or transmitter |
| TRL | Transition level |
| TROP | Tropopause |
| TS | Thunderstorm (followed by RA=Rain, SN=snow, PL=ice pellets, GR=hail, GS=small hail and/or snow pellets or combinations thereof, e.g. TSRASN = thunderstorm with rain and snow) |
| TS | Thunderstorm (in aerodrome reports and forecasts, TS used alone means thunder heard but no precipitation at the aerodrome) |
| TSR | Terminal surveillance radar* |
| TSSR | Terminal secondary surveillance radar* |
| TTR | Terminal Transition Route* |
| TUE | Tuesday |
| TURB | Turbulence |
| TVOR | Terminal VOR |
| TWR | Aerodrome control tower or aerodrome control |
| TWY | Taxiway |
| TX | Maximum temperature |
| TXL | Taxilane |
| TYP | Type of aircraft |
| TYPH | Typhoon |
| U | |
| U/S | Unserviceable |
| U/SLG | Under slung* |
| UCARA | Uncontrolled airspace reporting area* |
| UFN | Until further notice |
| ULR | Ultra long range |
| UNL | Unlimited |
| UP | Unidentified precipitation (in automated METAR/SPECI) |
| UTC | Co-ordinated Universal Time |
| V | |
| V | Variations in the mean wind direction (preceded and followed by figures in METAR/SPECI, e.g. 350V070) |
| VA | Volcanic ash |
| VAC | Visual approach chart |
| VAR | Magnetic variation |
| VC | Vicinity of the aerodrome (followed by FG=fog, FC=funnel cloud, SH=showers, PO=dust/sand whirls, BLDU=blowing dust, BLSA=blowing sand, BLSN=blowing snow, DS=duststorm, SS=sandstorm, TS=thunderstorm or VA=volcanic ash, e.g. VCFG= vicinity fog) |
| VCP | VOR check point* |
| VDF | Very high frequency direction-finding station |
| VFR | Visual flight rules |
| VHF | Very high frequency (30 - 300 MHz) |
| VIP | Very important person |
| VIS | Visibility |
| VMC | Visual meteorological conditions |
| VOL | Volume (followed by I, II...) |
| VOLMET | Meteorological information for aircraft in flight |
| VOR | VHF omnidirectional radio range |
| VORTAC | VOR and TACAN combination |
| VPA | Vertical path angle |
| VRB | Variable |
| VV | Vertical visibility |
| W | |
| W | West or western longitude |
| WAAS | Wide area augmentation system |
| WAC | World aeronautical chart - ICAO 1:1 000 000 |
| WB | Westbound |
| WBAR | Wingbar lights |
| WED | Wednesday |
| WEF | With effect from or effective from |
| WIE | With immediate effect or effective immediately |
| WILCO | Will comply |
| WINTEM | Forecast upper wind and temperature for aviation* |
| WIP | Work in progress |
| WNW | West north west |
| WPT | Way-point |
| WRNG | Warning |
| WS | Wind shear |
| WSW | West south west |
| WT | Weight |
| WTWS | Windshear and Turbulence Warning System* |
| WX | Weather |
| X | |
| X | Cross |
| XBAR | Crossbar (of approach lighting system) |
| XNG | Crossing |
| XS | Atmospherics |
| Y | |
| YCZ | Yellow caution zone (runway lighting) |
| YR | Your |
| Z | |
| Z | Co-ordinated Universal Time (in meteorological messages) |
| ZNC | Zone Control* |