GEN 2.2 ABBREVIATIONS USED
A — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| AAIM | aircraft autonomous integrity monitoring |
| AAL | above aerodrome level |
| ABI | advance boundary information |
| ABM | abeam |
| ABN | aerodrome beacon |
| ABV | above |
| AC | altocumulus |
| ACARS | aircraft communication addressing and reporting system (to be pronounced ‘AY-CARS’) |
| ACAS | airborne collision avoidance system |
| ACC | area control, a type of atc discipline |
| ACFT | aircraft |
| ACK | acknowledge |
| ACN | aircraft classification number |
| ACP | acceptance (message type designator) |
| ACPT | accept or accepted |
| ACT | active or activated or activity |
| AD | aerodrome |
| ADA | advisory area |
| ADC | aerodrome chart |
| ADDN | addition or additional |
| ADF | automatic direction finding equipment |
| ADJ | adjacent |
| ADR | advisory route |
| ADS | automatic dependent surveillance |
| ADS-B | automatic dependent surveillance – broadcast |
| ADS-C | automatic dependent surveillance – contract |
| ADSU | automatic dependent surveillance unit |
| AFIS | aerodrome flight information service |
| AFM | yes or affirm or affirmative or that is correct |
| AFTN | aeronautical fixed telecommunication network |
| AGL | above ground level |
| AGN | again |
| AIC | aeronautical information circular |
| 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) |
| ALT | altitude |
| ALTN | alternate aerodrome |
| AMD | amend or amended (used to indicate amended meteorological message; message type designator) |
| AMSL | above mean sea level |
| AP | airport |
| APAPI | abbreviated PAPI |
| APCH | approach |
| APN | apron |
| APP | approach control, a type of atc discipline |
| APU | auxiliary power unit |
| ARP | aerodrome reference point |
| AS | altostratus |
| ASC | ascent to or ascending to |
| ASDA | accelerate stop distance available |
| ASHTAM | special series NOTAM notifying, by means of a specific format, change in activity of a volcano, a volcanic eruption and/or volcanic ash cloud that is of significance to aircraft operations |
| ASPH | asphalt |
| AT | at (followed by time at which weather change is forecast to occur) |
| ATA | actual time of arrival |
| ATC | air traffic control (in general) |
| 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 |
| AUX | auxiliary |
| AVBL | available or availability |
| AVG | average |
| AVGAS | aviation gasoline |
| AWY | airway |
| AZM | azimuth |
B — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| BASE | cloud base |
| BCFG | fog patches |
| BCN | beacon (aeronautical ground light) |
| BCST | broadcast |
| BDRY | boundary |
| BECMG | becoming |
| BFR | before |
| BKN | broken |
| BL | blowing (followed by DU=dust, SA=sand or SN=snow) |
| BLW | below… |
| BR | mist |
| BTN | between |
C — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| C | centre (preceded by runway designation number to identify a parallel runway) |
| C | degrees Celsius (Centigrade) |
| CAA | Civil Avaition Authority |
| CAT | clear air turbulence |
| CAVOK | visibility, cloud and present weather better than prescribed values or conditions (to be pronounced ‘KAV-OH-KAY’) |
| CB | cumulonimbus (to be pronounced ‘CEE BEE’) |
| CC | cirrocumulus |
| CDA | continuous descent approach |
| CDN | co-ordination (message type designator) |
| CH | channel |
| CHG | modification (message type designator) |
| CI | cirrus |
| CLR | clear(s) or cleared to… or clearance |
| 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 |
| COORD | co-ordinates |
| CPDLC | controller-pilot data link communications |
| CPL | current flight plan (message type designator) |
| CRC | cyclic redundancy check |
| CS | cirrostratus |
| CS | call sign |
| CTA | control area |
| CTC | contact |
| CTL | control |
| CTOT | calculated take-off time |
| CTR | control zone |
| CU | cumulus |
| CUF | cumuliform |
| CVR | cockpit voice recorder |
| CWY | clearway |
D — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| D | danger area (followed by identification) |
| D | downward (tendency in RVR during previous 10 minutes) |
| D-ATIS | data link automatic terminal information service (to be pronounced ‘DEE-ATIS’) |
| D-VOLMET | data link VOLMET |
| DA | decision altitude |
| DCT | direct (in relation to flight plan clearances and type of approach) |
| DEG | degrees |
| DEL | clearance delivery, a type of atc discipline |
| DEP | depart or departure |
| DEST | destination |
| DETRESFA | distress phase |
| DF | direction finding |
| DFTI | distance from touchdown indicator |
| DH | decision height |
| DIST | distance |
| DIV | divert or diverting |
| DLA | delay or delayed |
| DLA | delay (message type designator) |
| DME | distance measuring equipment |
| DP | dew point temperature |
| DR | dead reckoning |
| DR | low drifting (followed by DU=dust, SA=sand or SN=snow) |
| DS | duststorm |
| DSB | double sideband |
| DTAM | descend to and maintain |
| DTHR | displaced runway threshold |
| DTRT | deteriorate or deteriorating |
| DU | dust |
| DVOR | Doppler VOR |
| DVORTAC | Doppler VOR and TACAN |
| DZ | drizzle |
E — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| E | east or eastern longitude |
| EAT | expected approach time |
| EET | estimated elapsed time |
| EFIS | electronic flight instrument system |
| EGNOS | European geostationary navigation overlay service (to be pronounced ‘EGG-NOS’) |
| EHF | extremely high frequency (30 to 300 GHz) |
| ELBA | emergency location beacon – aircraft |
| ELEV | elevation |
| ELT | emergency locator transmitter |
| EMBD | embedded in a layer (to indicate cumulonimbus 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 (as message type designator), estimated (preceded by time-group) |
| ETA | estimated time of arrival or estimating arrival |
| ETD | estimated time of departure or estimating departure |
| ETO | estimated time over significant point |
| EXP | expect or expected or expecting |
F — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| F | degrees Fahrenheit |
| FAC | facilities |
| FAF | final approach fix |
| FAP | final approach point |
| FAS | final approach segment |
| FBL | light (used to indicate the intensity of weather phenomena, interference or static reports, e.g. FBL RA=light rain) |
| FC | funnel cloud (tornado or water spout) |
| FCST | forecast |
| FCT | friction coefficient |
| FEW | few |
| FG | fog |
| FIC | flight information centre |
| FIR | flight information region |
| FIS | flight information service |
| FL | flight level |
| FLUC | fluctuating or fluctuation or fluctuated |
| FM | from (followed by time weather change is forecast to begin) |
| FMC | flight management computer |
| FMS | flight management system |
| FNA | final approach |
| FPL | filed flight plan (message type designator) |
| FPM | feet per minute |
| FREQ | frequency |
| FRONT | front (relating to weather) |
| FROST | frost (used in aerodrome warnings) |
| FSS | flight service station |
| ft | feet (dimensional unit) |
| FU | smoke |
| FZ | freezing |
| FZDZ | freezing drizzle |
| FZFG | freezing fog |
| FZRA | freezing rain |
G — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| G | variations from the mean wind speed (gusts) (followed by figures in METAR/SPECI and TAF) |
| GA | general aviation |
| GBAS | ground-based augmentation system (to be pronounced ‘GEE-BAS’) |
| GCA | ground controlled approach system or ground controlled approach |
| GEN | general |
| GHz | giga Hertz (= 1000 MHz) |
| GLONASS | global orbiting navigation satellite system (to be pronounced ‘GLO-NAS’) |
| GLS | GBAS landing system |
| GMC | ground movement chart (followed by name/title) |
| GND | ground movement control, part of aerodrome control, a type of atc discipline |
| GNSS | global navigation satellite system |
| GP | glide path |
| GPA | glide path angle |
| GPIP | glide path intercept point |
| GPS | global positioning system |
| GPU | ground power unit |
| GPWS | ground proximity warning system |
| GR | hail |
| GRAS | ground-based regional augmentation system (to be pronounced ‘GRASS’) |
| GRIB | processed meteorological data in the form of grid point values expressed in binary form (meteorological code) |
| GRVL | gravel |
| GS | ground speed |
| GS | small hail and/or snow pellets |
| GUND | geoid undulation |
H — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| H | hourly |
| h | half-hourly |
| H24 | continuous day and night service |
| HDG | heading |
| HF | high frequency (3 to 30 MHz) |
| HGT | height or height above |
| hPa | hectopascal |
| HR | hours |
| HURCN | hurricane |
| HVY | heavy |
| HVY | heavy (used to indicate the intensity of weather phenomena, e.g. HVY RA=heavy rain) |
| HZ | haze |
| Hz | Hertz (cycle per second) |
I — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| IAF | initial approach fix |
| IAP | instrument approach procedure |
| IAS | indicated air speed |
| IC | ice crystals (very small ice crystals in suspension, also known as diamond dust) |
| ICE | icing |
| ID | identifier or identify |
| IDENT | identification |
| IF | intermediate approach fix |
| IFF | identification friend/foe |
| IFR | instrument flight rules |
| ILS | instrument landing system |
| IM | inner marker |
| IMC | instrument meteorological conditions |
| INBD | inbound |
| INCERFA | uncertainty phase |
| INFO | information |
| INOP | inoperative |
| INS | inertial navigation system |
| INT | intersection |
| INTL | international |
| IR | ice on runway |
| IRS | inertial reference system |
| ISA | international standard atmosphere |
| ISB | independent sideband |
J — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
K — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| kg | kilograms |
| kHz | kilohertz |
| KIAS | knots indicated airspeed |
| km | kilometres |
| kmH | kilometres per hour |
| kPa | kilopascal |
| KT | knots |
| kW | kilowatts |
L — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| L | locator (see LM, LO) |
| L | left (preceded by runway designation number to identify a parallel runway) |
| LAT | latitude |
| lb | pounds (weight) |
| LCN | load classification number |
| LDA | landing distance available |
| LDAH | landing distance available, helicopter |
| LDI | landing direction indicator |
| LEN | length |
| LF | low frequency (30 to 300 kHz) |
| LGT | light or lighting |
| LGTD | lighted |
| LLZ | localizer (old) |
| LM | locator, middle |
| LMT | local mean time |
| LNAV | lateral navigation (FMS) |
| LO | locator, outer |
| LOC | localizer |
| LONG | longitude |
| LORAN | LORAN (long range air navigation system) |
| LV | light and variable (relating to wind) |
| LVL | level |
| LVP | low visibility procedures |
M — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| M | mach number (followed by figures) |
| M | minimum value of runway visual range (followed by figures in METAR/SPECI) |
| m | metres (preceded by figures) |
| MAG | magnetic |
| MAHF | missed approach holding fix |
| MAP | aeronautical maps and charts |
| MAPT | missed approach point |
| MATF | missed approach turning fix |
| MAX | maximum |
| MBST | microburst |
| MDA | minimum descent altitude |
| MDF | medium frequency direction finding station |
| MDH | minimum descent height |
| MEA | minimum en route altitude |
| MET | meteorological or meteorology |
| MET REPORT | local routine meteorological report (in abbreviated plain language) |
| METAR | aerodrome routine meteorological report (in meteorological code) |
| MF | medium frequency (300 to 3000 kHz) |
| MFA | minimum flight altitude |
| MHDF | medium and high frequency direction finding stations (at the same location) |
| MHVDF | medium, high and very high frequency direction finding stations (at the same location) |
| MHz | megahertz |
| MID | mid point (related to RVR) |
| MIFG | shallow fog |
| MIL | military |
| MIN | minutes |
| MKR | marker radio beacon |
| MLA | microlight aeroplane |
| MLS | microwave landing system |
| MLW | maximum certificated landing weight |
| MM | middle marker |
| MNM | minimum |
| MNPS | minimum navigation performance specifications |
| MOC | minimum obstacle clearance (required) |
| MOCA | minimum obstacle clearance altitude |
| MOD | moderate (used to indicate the intensity of weather phenomena, interference of static reports, e.g. MOD RA=moderate rain) |
| MOGAS | motor gasoline (premiumgrade or fourstar) |
| mps | metres per second |
| MRVA | minimum radar vector altitude |
| MSA | minimum sector altitude |
| MSAW | minimum safe altitude warning |
| MSG | message |
| MSL | Mean Sea Level |
| MSR | message… (transmission identification) has been misrouted (to be used in AFS as a procedure signal) |
| MSSR | monopulse secondary surveillance radar |
| MTOW | maximum take-off weight |
| MVA | minimum vectoring altitudes |
| MX | mixed type of ice formation (white and clear) |
N — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| N | no distinct tendency (in RVR during previous 10 minutes) |
| N | north or northern latitude |
| NA | not applicable |
| NADP | noise abatement departure procedure |
| NAV | navigation |
| NC | no change |
| NCD | no cloud detected (used in automated METAR/SPECI) |
| NDB | non-directional radio beacon |
| NE | north-east |
| NEG | no or negative or permission not granted or that is not correct |
| NGT | night |
| NIL | none or i have nothing to send to you |
| NM | nautical miles |
| NML | normal |
| NNE | north-north-east |
| NNW | north-north-west |
| NO | no (negative) (to be used in AFS as a procedure signal) |
| NOSIG | no significant change (used in trend-type landing forecasts) |
| NOTAM | a notice 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 |
| NPA | non-precision approach |
| NR | number |
| NS | nimbostratus |
| NSC | nil significant cloud |
| NSW | nil significant weather |
| NW | north-west |
| NXT | next |
O — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| OBS | observe or observed or observation |
| OBSC | obscure or obscured or obscuring |
| OBST | obstacle |
| OCA | obstacle clearance altitude |
| OCA | oceanic control area |
| OCC | occulting (light) |
| OCH | obstacle clearance height |
| OHD | overhead |
| OM | outer marker |
| OPA | opaque, white type of ice formation |
| OTLK | outlook (used in SIGMET messages for volcanic ash and tropical cyclones) |
| OVC | overcast |
P — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| P | prohibited area (followed by identification) |
| P | maximum value of wind speed or runway visual range (followed by figures in METAR/SPECI and TAF) |
| PA | precision approach |
| PALS | precision approach lighting system (specify category) |
| PANS | procedures for air navigation services |
| PAPI | precision approach path indicator |
| PAR | precision approach radar |
| PARL | parallel |
| PATC | precision approach terrain chart |
| PAX | passenger(s) |
| PBN | performance-based navigation |
| PCL | pilot-controlled lighting |
| PCN | pavement classification number |
| PERM | permanent |
| PIB | pre-flight information bulletin |
| PL | ice pellets |
| PLN | flight plan |
| PNR | point of no return |
| PO | dust/sand whirls (dust devils) |
| POB | persons on board |
| PRFG | aerodrome partially covered by fog |
| PRI | primary |
| PRKG | parking |
| PROB | probability |
| PROC | procedure |
| PSN | position |
| PSR | primary surveillance radar |
| PTN | procedure turn |
| PWR | power |
Q — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| QDM | magnetic heading (zero wind) |
| QDR | magnetic bearing |
| QFE | atmospheric pressure at aerodrome elevation (or at runway threshold) |
| QFU | magnetic orientation of runway |
| QGE | what is my distance to your station? or your distance to my station is
(distance figures and units) (to be used in radiotelegraphy as a Q code) |
| QNH | altimeter sub-scale setting to obtain elevation when on the ground |
| QTE | true bearing |
R — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| R | right (preceded by runway designation number to identify a parallel runway) |
| R | restricted area (followed by identification) |
| R | runway (followed by figures in METAR/SPECI) |
| RA | rain |
| RA | resolution advisory |
| RAG | ragged |
| RAIM | receiver autonomous integrity monitoring |
| RAPCON | radar approach control |
| RCC | rescue co-ordination centre |
| RCF | radiocommunication failure (message type designator) |
| RCL | runway centre line |
| RCLL | runway centre line light(s) |
| RCLR | recleared |
| RDH | reference datum height |
| RDL | radial |
| RDO | radio |
| RE | recent (used to qualify weather phenomena e.g. RERA=recent rain) |
| REDL | runway edge light(s) |
| REG | registration |
| RENL | runway end light(s) |
| REP | report or reporting or reporting point |
| REQ | request or requested |
| RESA | runway end safety area |
| RMK | remark |
| RNAV | area navigation (to be pronounced ‘AR-NAV’) |
| RNG | radio range |
| RNP | required navigation performance |
| ROC | rate of climb |
| ROD | rate of descent |
| RPL | repetitive flight plan |
| RTE | route |
| RTF | radiotelephone |
| RTODAH | rejected take-off distance available, helicopter |
| RVR | runway visual range |
| RVSM | reduced vertical separation minimum (300 m (1000 ft)) between FL 290 and FL 410 |
| RWY | runway |
S — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| S | special meteorological report (in abbreviated plain language) |
| S | south or southern latitude |
| SA | sand |
| SALS | simple approach lighting system |
| SAR | search and rescue |
| SATCOM | satellite communication |
| SBAS | satellite-based augmentation system (to be pronounced ‘ESS-BASS’) |
| SC | stratocumulus |
| SCT | scattered |
| SDBY | stand by |
| SE | south-east |
| SEC | seconds |
| SECN | section |
| SECT | sector |
| SELCAL | selective calling system |
| SFC | surface |
| SG | snow grains |
| SGL | signal |
| 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) |
| SHF | super high frequency (3 to 30 GHz) |
| SI | international system of units |
| SID | standard instrument departure |
| SIGMET | information concerning en route weather phenomena which may affect the safety of aircraft operations |
| SIMUL | simultaneous or simultaneously |
| SKC | sky clear |
| SMC | surface movement control |
| SMR | surface movement radar |
| SN | snow |
| SNOCLO | aerodrome closed due to snow (used in METAR/SPECI) |
| SNOWTAM | a special series NOTAM notifying the presence or removal of hazardous conditions due to snow, ice, slush or standing water associated with snow, slush and ice on the movement area, by means of a specific format |
| SPECI | aerodrome special meteorological report (in meteorological code) |
| SQ | squall |
| SQL | squall line |
| SRA | special rules area |
| SS | sandstorm |
| SSB | single sideband |
| SSR | secondary surveillance radar |
| SST | supersonic transport |
| SSW | south-south-west |
| ST | stratus |
| STAR | standard instrument arrival |
| STD | standard |
| STOL | short take-off and landing |
| STS | status |
| STWL | stopway light(s) |
| SUP | supplement (AIP supplement) |
| SUPPS | regional supplementary procedures |
| SVC | service message |
| SW | south-west |
| SWC | significant weather chart |
| SWY | stopway |
T — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| T | temperature |
| T | true (preceded by a bearing to indicate reference to true north) |
| T-VASIS | T visual approach slope indicator system (to be pronounced ‘TEE-VASIS’) |
| TA | traffic advisory |
| TA | transition altitude |
| TACAN | UHF tactical air navigation aid |
| TAF | aerodrome forecast (in meteorological code) |
| TAS | true airspeed |
| TC | tropical cyclone |
| TCAS RA | traffic alert and collision avoidance system resolution advisory (to be pronounced “TEE-CAS-AR-AY”) |
| TCH | threshold crossing height |
| TCP | transfer of control point, a point (fix/VOR/NDB or airspace boundary), where control of an aircraft is transferred from one ATC to another |
| TCU | towering cumulus |
| TDO | tornado |
| TDZ | touchdown zone |
| TEMPO | temporary or temporarily |
| TFC | traffic |
| TG | touch-and-go |
| THR | threshold |
| TIBA | traffic information broadcast by aircraft |
| TIL | until |
| TKOF | take-off |
| TL | till (followed by time by which weather change is forecast to end) |
| TL | transition level |
| TLOF | touchdown and lift-off area |
| TMA | terminal control area |
| TMZ | transponder mandatory zone |
| TN | minimum temperature (followed by figures in TAF) |
| TNA | turn altitude |
| TNH | turn height |
| TO | to… (place) |
| TOC | top of climb |
| TODA | take-off distance available |
| TODAH | take-off distance available, helicopter |
| TOP | cloud top |
| TORA | take-off run available |
| TP | turning point |
| TR | track |
| TRA | temporary reserved airspace |
| TRANS | transmits or transmitter |
| TREND | trend forecast |
| TRL | transition level |
| TROP | tropopause |
| TS | thunderstorm (in aerodrome reports and forecasts, TS used alone means thunder heard but no precipitation at the aerodrome) |
| 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) |
| TSA | temporary segregated area |
| TSUNAMI | tsunami (used in aerodrome warnings) |
| TURB | turbulence |
| TWR | tower control, part of aerodrome control, a type of atc discipline |
| TWY | taxiway |
| TXT | text (when the abbreviation is used to request a erpetition, the question mark (IMI) precedes the abbreviation, e.g. IMI TXT) (to be used in AFS as a procedure signal) |
| TYP | type of aircraft |
| TYPH | typhoon |
U — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| U | upward (tendency in RVR during previous 10 minutes) |
| U/S | unserviceable |
| UAC | upper area control centre |
| UDF | ultra high frequency direction finding station |
| UHF | ultra high frequency (300 to 3000 MHz) |
| UIR | upper flight information region |
| UNL | unlimited |
| UP | unidentified precipitation (used in METAR/SPECI) |
| UTA | upper control area |
| UTC | co-ordinated universal time |
V — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| V | variations from the mean wind direction (preceded and followed by figures in METAR/SPECI, e.g. 350V070) |
| VA | volcanic ash |
| VAAC | volcanic ash advisory centre |
| VAR | magnetic variation |
| VASIS | visual approach slope indicator system |
| 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) |
| VDF | very high frequency direction finding station |
| VDGS | visual docking guidance system |
| VFR | visual flight rules |
| VHF | very high frequency (30 to 300 MHz) |
| VIS | visibility |
| VLF | very low frequency (3 to 30 kHz) |
| VMC | visual meteorological conditions |
| VNAV | vertical navigation (to be pronounced “VEE-NAV”) |
| VOLMET | meteorological information for aircraft in flight |
| VOR | VHF omnidirectional radio range |
| VORTAC | VOR and TACAN combination |
| VRB | variable |
| VSP | vertical speed |
| VTOL | vertical take-off and landing |
| VV | vertical visibility (followed by figures in METAR/SPECI and TAF) |
| VWS | vertical wind shear |
W — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| W | west or western longitude |
| WAAS | wide area augmentation system |
| WAC | world aeronautical chart ICAO 1:1 000 000 |
| WBAR | wing bar lights |
| WDI | wind direction indicator |
| WGS-84 | world geodetic system – 1984 |
| WILCO | will comply |
| WINTEM | forecast upper wind and temperature for aviation |
| WIP | work in progress |
| WNW | west-north-west |
| WPT | waypoint |
| WRNG | warning |
| WS | wind shear |
| WSW | west-south-west |
| WT | weight |
| WTSPT | waterspout |
| WWW | world wide web |
| WX | weather |
| WXR | weather radar |
X — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| X | cross |
| XBAR | crossbar (of approach lighting system) |
Y — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Z — A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
| Z | co-ordinated universal time (in meteorological messages) |