+: Abbreviations annotated by "+" are not included in ICAO Doc 8400.
†: When radiotelephony is used, the abbreviations and terms annotated by "†", are transmitted as spoken words.
: When radiotelephony is used, the abbreviations and terms are transmitted using the individual letters in non-phonetic form.
“*” Signal is also available for use in communicating with stations of the maritime mobile service.
“# “Signal for use in the teletypewriter service only.
| 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 GLOSSARY OF TERMS | |
| A | Amber |
| AAA | (Or AAB, AAC... etc. in sequence) Amended meteorological message (message type designator) |
| A/A | Air-to-air |
| AAD | Assigned altitude deviation |
| AAIM | Aircraft autonomous integrity monitoring |
| AAL | Above aerodrome level |
| AAR | Air to air refuelling |
| A2A | +Amplitude modulation, Designation of emissions |
| A3E | +Amplitude modulation, Designation of emissions |
| A8W | +Amplitude modulation, Designation of emissions |
| A9W | +Amplitude modulation, Designation of emissions |
| ABI | Advance boundary information |
| ABM | Abeam |
| ABN | Aerodrome beacon |
| ABT | About |
| ABV | Above |
| AC | Altocumulus |
| ACARS | †(to be pronounced ”AY-CARS”) Aircraft communication addressing and reporting system |
| ACAS | †Airborne collision avoidance system |
| ACC | Area control centre or area control |
| ACCC | +Air Command and Control Centre |
| ACCID | Notification of an aircraft accident |
| ACFT | Aircraft |
| ACK | Acknowledge |
| ACL | Altimeter check location |
| ACL | +ATC clearances and instructions |
| ACM | +ATC communications management |
| 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 |
| ADIZ | †(to be pronounced “AY-DIZ”) Air defence identification zone |
| ADJ | Adjacent |
| ADO | Aerodrome office (specify service) |
| ADR | Advisory route |
| ADS | +Automatic dependent surveillance |
| ADS | *The address (when this abbreviation is used to request a repetition, the question mark (IMI) precedes the abbreviation, e.g. IMI ADS) (to be used in AFS as a procedure signal) |
| ADS-B | ‡Automatic dependent surveillance — broadcast |
| ADS-C | ‡Automatic dependent surveillance — contract |
| ADSU | Automatic dependent surveillance unit |
| ADQ | +Aeronautical Data Quality |
| ADVS | Advisory service |
| ADZ | Advise |
| AES | Aircraft earth station |
| AFIL | Flight plan filed in the air |
| AFIS | Aerodrome flight information service |
| AFM | Yes or affirm or affirmative or that is correct |
| AFS | Aeronautical fixed service |
| AFT | After ... (time or place) |
| AFTN | Aeronautical fixed telecommunication network |
| A/G | Air-to-ground |
| AGA | Aerodromes, air routes and ground aids |
| AGL | Above ground level |
| AGN | Again |
| AIC | Aeronautical information circular |
| AIDC | Air traffic services interfacility data communications |
| AIM | Aeronautical information management |
| AIP | Aeronautical information publication |
| AIRAC | Aeronautical information regulation and control |
| AIREP | †Air-report |
| AIRMET | †Information concerning en-route weather phenomena which may affect the safety of low-level aircraft operations |
| AIS | Aeronautical information services |
| ALA | Alighting area |
| ALERFA | †Alert phase |
| ALR | Alerting (message type designator) |
| ALRS | Alerting service |
| ALS | Approach lighting system |
| ALT | Altitude |
| ALTN | Alternate or alternating (light alternates in colour) |
| ALTN | Alternate (aerodrome) |
| AMA | Area minimum altitude |
| AMC | +ATC microphone check |
| AMC | +Acceptable Means of Compliance |
| 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 |
| ANC | Aeronautical Chart - 1:500 000 ... (followed by name/title) |
| ANCS | Aeronautical Navigation Chart Small Scale ... (followed by name/title and scale) |
| ANS | Answer |
| AO | +Aircraft Operators |
| AOC | Aerodrome obstacle chart ... (followed by type and name / title) |
| AOC | +Air Operation Centre |
| AOC | +Air Operator Certificate – according to EC Regulation 965/2012 |
| AOCC | +Airport Operations Control Centre |
| AOO | +Airfield Operations Officer |
| AOR | +Area of responsibility |
| AP | Airport |
| APAPI | †(to be pronounced “AY-PAPI”) Abbreviated precision approach path indicator |
| APCH | Approach |
| APDC | Aircraft parking/docking chart ... (followed by name/title) |
| APN | Apron |
| APP | Approach control office or approach control or approach control service |
| APR | April |
| APRX | Approximate or approximately |
| APSG | After passing |
| APU | Auxiliary Power Unit |
| APV | Approach procedure with vertical guidance |
| APV | +Approve or approved or approval |
| ARC | Area chart |
| ARNG | Arrange |
| ARO | Air traffic services reporting office |
| ARP | Aerodrome reference point |
| ARP | Air-report (message type designator) |
| ARQ | Automatic error correction |
| ARR | Arrive or arrival |
| ARR | Arrival (message type designator) |
| ARS | Special air-report (message type designator) |
| ARST | Arresting (specify (part of) aircraft arresting equipment) |
| AS | Altostratus |
| ASAP | As soon as possible |
| ASARAS | +Air Search and Rescue Alert Service |
| ASC | Ascend to or ascending to |
| ASDA | Accelerate-stop distance available |
| ASE | Altimetry system error |
| ASHTAM | A 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 |
| ASMGCS | +Advanced Surface Movement Guidance and Control System |
| ASPEEDL | +Airspeed loss |
| 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) |
| ATCC | +Air Traffic Control Centre |
| ATCSMAC | Air Traffic Control Surveillance Minimum Altitude Chart ... (followed by name/title) |
| ATD | Actual time of departure |
| ATFCM | +Air traffic flow and capacity management |
| ATFM | Air traffic flow management |
| ATFMP | +Air traffic flow management position |
| ATFMU | +Air traffic flow management unit |
| ATIS | †(to be pronounced “AY-TIS”) Automatic terminal information service |
| ATM | Air traffic management |
| ATN | Aeronautical telecommunication network |
| ATP | +Allied Tactical Publication |
| ATP | At ... (time or place) |
| ATS | Air traffic services |
| ATSU | +Air traffic service unit |
| ATTN | Attention |
| AT-VASIS | †(to be pronounced “AY-TEE-VASIS”) Abbreviated T visual approach slope indicator system |
| ATZ | Aerodrome traffic zone |
| AUG | August |
| AUTH | Authorized or authorization |
| AUTO | Automatic |
| AUW | All up weight |
| AUX | Auxiliary |
| AVBL | Available or availability |
| AVG | Average |
| AVGAS | †Aviation gasoline |
| AWOS | Automated weather observation system |
| AWTA | Advise at what time able |
| 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 GLOSSARY OF TERMS | |
| B | Blue |
| BA | Braking action |
| BARO-VNAV | †(to be pronounced “BAA-RO-VEENAV”) Barometric vertical navigation |
| BASE | †Cloud base |
| BCFG | Fog patches |
| BCN | Beacon (aeronautical ground light) |
| BCST | Broadcast |
| BDRY | Boundary |
| BECMG | Becoming |
| BFR | Before |
| BIP | +Border Inspection Point |
| BKN | Broken |
| BL | Blowing ... (followed by DU = dust, SA = sand or SN = snow) |
| BLDG | Building |
| BLO | Below clouds |
| BLW | Below... |
| BOMB | Bombing |
| BoMCT | +Beginning of morning civil twilight |
| BR | Mist |
| BRF | Short (used to indicate the type of approach desired or required) |
| BRG | Bearing |
| BRKG | Braking |
| B-RNAV | +Basic area navigation |
| BS | Commercial broadcasting station |
| BSRF | +Bird Strike Reporting Form |
| BTL | Between layers |
| BTN | Between |
| BUFR | Binary universal form for the representation of meteorological data |
| 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 GLOSSARY OF TERMS | |
| C | ... Centre (preceded by runway designation number to identify a parallel runway) |
| C | Degrees Celsius (centigrade) |
| CA | Course to an altitude |
| CAA | Civil Aviation Authority or civil aviation administration |
| CAT | Category |
| CAT | Clear air turbulence |
| CAVOK | †(to be pronounced "KAV-OH-KAY") Visibility, cloud and present weather better than prescribed values or conditions |
| CB | ‡(to be pronounced “CEE-BEE”) Cumulonimbus |
| CC | Cirrocumulus |
| CC | +Condition Code |
| CCA | (or CCB, CCC... etc., in sequence) Corrected meteorological message (message type designator) |
| CCO | Continuous climb operations |
| CD | Candela |
| CDN | Coordination (message type designator) |
| CDO | Continuous descent operations |
| CDR | Conditional Route |
| CEATS | +Central European Air Traffic Services |
| CET | +Central European Time |
| CF | Change frequency to... |
| CF | Course to a fix |
| CFM | *Confirm or I confirm (to be used in AFS as a procedure signal) |
| CGL | Circling guidance light(s) |
| CH | Channel |
| CH | #This is a channel – continuity - check of transmission to permit comparison of your record of channel-sequence numbers of messages received on the channel (to be used in AFS as a procedure signal) |
| CHEM | Chemical |
| CHG | Modification (message type designator) |
| CI | Cirrus |
| CIDIN | †Common ICAO data interchange network |
| CIT | +Near or over large towns |
| CITES | +Convention on International Trade in Endangered Species of Wild Fauna and Flora |
| CIV | Civil |
| CK | Check |
| 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 (used in METAR/SPECI) |
| CLSD | Close or closed or closing |
| CM | Centimetre |
| CMB | Climb to or climbing to |
| CMPL | Completion or completed or complete |
| CNL | Cancel or cancelled |
| CNL | Flight plan cancellation (message type designator) |
| CNS | Communications, navigation and surveillance |
| COM | Communications |
| CONC | Concrete |
| COND | Condition |
| CONS | Continuous |
| CONST | Construction or constructed |
| CONT | Continue(s) or continued |
| COOR | Coordinate or coordination |
| COORD | Coordinates |
| COP | Change-over point |
| COR | Correct or correction or corrected (used to indicate corrected meteorological message; message type designator) |
| COT | At the coast |
| COV | Cover or covered or covering |
| CPDLC | ‡Controller-pilot data link communications |
| CPL | Current flight plan (message type designator) |
| CRC | Cyclic redundancy check |
| CRM | Collision risk model |
| CRP | Compulsory reporting point |
| CRZ | Cruise |
| CS | Cirrostratus |
| CS | Call sign |
| CTA | Control area |
| CTAM | Climb to and maintain |
| CTC | Contact |
| CTL | Control |
| CTN | Caution |
| CTOT | +Calculated take-off time |
| CTR | Control zone |
| CU | Cumulus |
| CUF | Cumuliform |
| CUST | Customs |
| CVR | Cockpit voice recorder |
| CW | Continuous wave |
| 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 GLOSSARY OF TERMS | |
| D | Downward (tendency in RVR during previous 10 minutes) |
| D | Danger area ... (followed by identification) |
| DA | Decision altitude |
| DAM | +Duty Airside Manager |
| DAP | +Downlinked Aircraft Parameter |
| D - ATIS | †(to be pronounced “DEE – ATIS”) Data link automatic terminal information service |
| D - VOLMET | Data link VOLMET |
| DCD | Double channel duplex |
| DCKG | Docking |
| DCP | Datum crossing point |
| DCPC | Direct controller-pilot communications |
| DCS | Double channel simplex |
| DCT | Direct (in relation to flight plan clearances and type of approach) |
| DE | *From (used to precede the call sign of the calling station) (to be used in AFS as a procedure signal) |
| DEC | December |
| DEG | Degrees |
| DEP | Depart or departure |
| DEP | Departure (message type designator) |
| DEPO | Deposition |
| DER | Departure end of the runway |
| DES | Descend to or descending to |
| DEST | Destination |
| DETRESFA | †Distress phase |
| DEV | Deviation or deviating |
| DF | Direction finding |
| DFDR | Digital flight data recorder |
| DFTI | Distance from touch down indicator |
| DGCA | +Director General of Civil Aviation |
| DH | Decision height |
| DHDG | +Downlinked Magnetic Heading |
| DIAS | +Downlinked Indicated Air Speed |
| DIF | Diffuse |
| DIST | Distance |
| DIV | Divert or diverting |
| DLA | Delay or delayed |
| DLA | Delay (message type designator) |
| DLIC | Data link initiation capability |
| DLY | Daily |
| DMACH | +Downlinked Mach Number |
| DME | Distance measuring equipment |
| DNG | Danger or dangerous |
| DOF | Date of flight |
| DOM | Domestic |
| DP | Dew point temperature |
| DPT | Depth |
| DR | Dead reckoning |
| DR | Low drifting ... (followed by DU = dust, SA = sand or SN = snow |
| DRC | +Downlinked Rate of Climb/Descend |
| DRG | During |
| DS | Duststorm |
| DSB | Double sideband |
| DSFL | +Downlinked Selected Flight Level |
| DTAM | Descend to and maintain |
| DTG | Date-time group |
| DTHR | Displaced runway threshold |
| DTRT | Deteriorate or deteriorating |
| DTW | Dual tandem wheels |
| DU | Dust |
| DUC | Dense upper cloud |
| DUPE | #This is a duplicate message (to be used in AFS as a procedure signal) |
| DUR | Duration |
| DVD | +Digital Versatile Disc |
| DVOR | Doppler VOR |
| DW | Dual wheels |
| 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 GLOSSARY OF TERMS | |
| E | East or eastern longitude |
| EASA | +European Aviation Safety Agency |
| EAT | Expected approach time |
| EB | Eastbound |
| ECAA | +European Common Aviation Area |
| EDA | Elevation differential area |
| EDTO | Extended diversion time operations |
| EEE | #Error (to be used in AFS as a procedure signal) |
| EET | Estimated elapsed time |
| EFC | Expect further clearance |
| EFIS | †(to be pronounced “EE-FIS”) Electronic flight instrument system |
| eFPL | Filed flight plan exchanged via flight and flow — information for a collaborative environment (FF-ICE) services |
| EFTA | +European Free Trade Association |
| EGM | +Earth Gravitational Model 1996 |
| EGNOS | (to be pronounced “EGG-NOS”) European geostationary navigation overlay service |
| EHF | Extremely high frequency (30 000 to 300 000 MHZ) |
| EHS | +Enhanced Surveillance |
| ELBA | Emergency location beacon — aircraft |
| ELEV | Elevation |
| ELR | Extra long range |
| ELS | +Elementary Surveillance |
| ELT | Emergency locator transmitter |
| EM | Emission |
| 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 |
| ENRC | En route chart ... (followed by name/title) |
| EOBT | Estimated off-block time |
| EoECT | +End of evening civil twilight |
| EQN | Equatorial latitudes northern hemisphere |
| EQPT | Equipment |
| EQS | Equatorial latitudes southern hemisphere |
| ER | *Here...or herewith |
| ESE | East-south-east |
| EST | Estimate or estimated or estimation (message type designator) |
| ETA | *Estimated time of arrival or estimating arrival |
| ETD | Estimated time of departure or estimating departure |
| ETO | Estimated time over significant point |
| EU | +European Union |
| EUR | +Euros |
| EUR RODEX | European regional OPMET data exchange |
| EV | Every |
| EVS | Enhanced vision system |
| EXC | Except |
| EXER | Exercises or exercising or to exercise |
| EXP | Expect or expected or expecting |
| EXTD | Extend or extending or extended |
| 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 GLOSSARY OF TERMS | |
| F | Fixed |
| FA | Course from a fix to an altitude |
| FAC | Facilities |
| FAF | Final approach fix |
| FAL | Facilitation of international air transport |
| FANS | +Future Data Link |
| FAP | Final approach point |
| FAS | Final approach segment |
| FATO | Final approach and take-off area |
| FAX | Facsimile transmission |
| FAWP | +Final approach waypoint |
| FBL | Light (used to indicate the intensity of weather phenomena, interference or static reports, e.g. FBLRA = light rain) |
| FC | Funnel cloud (tornado or waterspout) |
| FCST | Forecast |
| FCT | Friction coefficient |
| FDPS | Flight data processing system |
| FEB | February |
| FEW | Few |
| FFR | +Flood, Fire, Relief |
| FG | Fog |
| FIC | Flight information centre |
| FIR | Flight information region |
| FIS | Flight information service |
| FISA | Automated flight information service |
| FL | Flight level |
| FLD | Field |
| FLG | Flashing |
| FLR | Flares |
| FLT | Flight |
| FLTCK | Flight check |
| FLUC | Fluctuating or fluctuation or fluctuated |
| FLW | Follow(s) or following |
| FLY | Fly or flying |
| FM | Course from a fix to manual termination (used in navigation database coding) |
| FM | From |
| FM | From ... (followed by time at which weather change is forecast to begin) |
| FMP | +Flow management position |
| FMC | Flight management computer |
| FMS | ‡Flight management system |
| FMU | Flow management unit |
| FNA | Final approach |
| FOD | +Foreign Object Debris |
| FPAP | Flight path alignment point |
| FPL | Filed flight plan exchanged via aeronautical fixed service (AFS) |
| FPM | Feet per minute |
| FPR | Flight plan route |
| FR | Fuel remaining |
| FRA | +Free Route Airspace |
| FREQ | Frequency |
| FRI | Friday |
| FRNG | Firing |
| FRONT | †Front (relating to weather) |
| FROST | †Frost (used in aerodrome warnings) |
| FRQ | Frequent |
| FSL | Full stop landing |
| FSS | Flight service station |
| FST | First |
| FT | Feet (dimensional unit) |
| FTE | Flight technical error |
| FTP | Fictitious threshold point |
| FTT | Flight technical tolerance |
| FU | Smoke |
| FUA | +Flexible use of airspace |
| 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 GLOSSARY OF TERMS | |
| G | Green |
| G | Variations from the mean wind speed (gusts) ... (followed by figures in METAR/SPECI and TAF) |
| GA | General aviation |
| GA | Go ahead, resume sending (to be used in AFS as a procedure signal) |
| G/A | Ground-to-air |
| G/A/G | Ground-to-air and air-to-ground |
| GAGAN | GPS and geostationary earth orbit augmented navigation |
| GAIN | Airspeed or headwind gain |
| GAMET | Area forecast for low-level flights |
| GARP | GBAS azimuth reference point |
| GAT | +General air traffic |
| GBAS | (to be pronounced “GEE-BAS”) Ground-based augmentation system |
| GCA | Ground controlled approach system or ground controlled approach |
| GDCA | +General Directorate of Civil Aviation |
| GEN | General |
| GEO | Geographic or true |
| GES | Ground earth station |
| GLD | Glider |
| GLONASS | †(to be pronounced “GLO-NAS”) Global orbiting navigation satellite system |
| GLS | GBAS landing system |
| GMC | Ground movement chart ... (followed by name/title) |
| GND | Ground |
| GNDCK | Ground check |
| GNSS | ‡Global navigation satellite system |
| GOV | Government |
| 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 | (to be pronounced “GRASS”) Ground-based regional augmentation system |
| GRASS | Grass landing area |
| GRF | +Global Reporting Format |
| GRIB | Processed meteorological data in the form of grid point values expressed in binary form (meteorological code) |
| GRN | +Green |
| 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 GLOSSARY OF TERMS | |
| H | High pressure area or the centre of high pressure |
| H | Significant wave height ... (followed by figures in METAR/SPECI) |
| H24 | Continuous day and night service |
| HA | Holding/racetrack to an altitude |
| HAPI | Helicopter approach path indicator |
| HBN | Hazard beacon |
| HCH | Heliport crossing height |
| HDF | High frequency direction-finding station |
| HDFC | +Hungarian Defence Forces Command |
| HDG | Heading |
| HEL | Helicopter |
| HF | Holding/racetrack to a fix |
| HF | High frequency (3 000 to 30 000 KHZ) |
| HGT | Height or height above |
| HIAL | +High intensity approach lights |
| HIRL | +High intensity runway lights |
| HJ | Sunrise to sunset |
| HLDG | Holding |
| HLP | Heliport |
| HLS | Helicopter landing site |
| HM | Holding/racetrack to a manual termination |
| HN | Sunset to sunrise |
| HNG | +Hungarian or Hungary |
| HNH | High latitudes northern hemisphere |
| HO | Service available to meet operational requirements |
| HOL | Holiday |
| HOSP | Hospital aircraft |
| HPA | Hectopascal |
| HR | Hours |
| HRP | Heliport reference point |
| HS | Service available during hours of scheduled operations |
| HSH | High latitudes southern hemisphere |
| HU | +Hungarian |
| HUD | Head-up display |
| HUF | +Hungarian Forints |
| HUM | Humanitarian |
| HURCN | Hurricane |
| HVDF | High and very high frequency direction-finding stations (at the same location) |
| HVY | Heavy |
| HVY | Heavy (used to indicate the intensity of weather phenomena, e.g. HVYRA = heavy rain) |
| HWS | +Horizontal wind shear |
| HX | No specific working hours |
| HYR | Higher |
| 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 GLOSSARY OF TERMS | |
| IAC | Instrument approach chart ... (followed by name/title) |
| IAF | Initial approach fix |
| IAIP | +Integrated Aeronautical Information Package |
| IAO | In and out of clouds |
| IAP | Instrument approach procedure |
| IAR | Intersection of air routes |
| IAS | Indicated airspeed |
| IATA | +International Air Transport Association |
| IBN | Identification beacon |
| IC | +Ice crystals (very small ice crystals in suspension, also known as diamond dust) |
| ICAO | International Civil Aviation Organization |
| ICE | Icing |
| ID | Identifier or identify |
| IDENT | †Identification |
| IF | Intermediate approach fix |
| IFF | Identification friend/foe |
| IFPS | +Integrated initial flight plan processing system |
| IFR | Instrument flight rules |
| IGA | International general aviation |
| ILS | Instrument landing system |
| IM | Inner marker |
| IMC | Instrument meteorological conditions |
| IMG | Immigration |
| IMI | *Interrogation sign (question mark) (to be used in AFS as a procedure signal) |
| IMPR | Improve or improving |
| IMT | Immediate or immediately |
| INA | Initial approach |
| INBD | Inbound |
| INC | In cloud |
| INCERFA | †Uncertainty phase |
| INCORP | Incorporated |
| INFO | †Information |
| INOP | Inoperative |
| INP | If not possible |
| INPR | In progress |
| INS | Inertial navigation system |
| INS | +Inches |
| 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 |
| IRS | Inertial reference system |
| ISA | International standard atmosphere |
| ISB | Independent sideband |
| ISOL | Isolated |
| 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 GLOSSARY OF TERMS | |
| JAA | +Joint Aviation Authorities |
| JAN | January |
| JFC | +Joint Forces Command |
| JTST | Jet stream |
| JUL | July |
| JUN | June |
| 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 GLOSSARY OF TERMS | |
| 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 GLOSSARY OF TERMS | |
| L | ... Left (preceded by runway designation number to identify a parallel runway) |
| L | Litre |
| L | Locator |
| L | Low pressure area or the centre of low pressure |
| LAM | Logical acknowledgement (message type designator) |
| LAN | Inland |
| LAT | Latitude |
| LCA | Local or locally or location or located |
| LDA | Landing distance available |
| LDAH | Landing distance available, helicopter |
| LDG | Landing |
| LDI | Landing direction indicator |
| LEN | Length |
| LF | Low frequency (30 to 300 KHZ) |
| LGT | Light or lighting |
| LGTD | Lighted |
| LI | +Locator inner |
| LIH | Light intensity high |
| LIL | Light intensity low |
| LIM | Light intensity medium |
| LINE | Line (used in SIGMET) |
| LLZ | +Localizer |
| LM | Locator, middle |
| LMT | Local mean time |
| LNAV | †(to be pronounced “EL-NAV”) Lateral navigation |
| LNG | Long (used to indicate the type of approach desired or required) |
| LO | Locator, outer |
| LOC | Localizer |
| LONG | Longitude |
| LORAN | Long range air navigation system |
| LOSS | Airspeed or headwind loss |
| LPV | Localizer performance with vertical guidance |
| LR | Last message received by me was ….(to be used in AFS as a procedure signal) |
| LRG | Long range |
| LS | Last message sent by me was … or Last message was... (to be used in AFS as a procedure signal) |
| LT | +Local Time |
| LTA | Lower control area |
| LTD | Limited |
| LTF | +Land line telephone |
| LTP | Landing threshold point |
| LTT | +Landline teletypewriter |
| LV | Light and variable (relating to wind) |
| LVE | Leave or leaving |
| LVL | Level |
| LVP | Low Visibility Procedures |
| LYR | Layer or layered |
| 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 GLOSSARY OF TERMS | |
| M | ... Metres (preceded by figures) |
| M | Mach number ... (followed by figures) |
| M | Minimum value of runway visual range ... (followed by figures in METAR/SPECI) |
| MAA | Maximum authorized altitude |
| MAG | Magnetic |
| MAHF | Missed approach holding fix |
| MAINT | Maintenance |
| MAP | Aeronautical maps and charts |
| MAPT | Missed approach point |
| MAR | March |
| MAR | At sea |
| MAS | +Manual A1 simplex |
| MATF | Missed approach turning fix |
| MATZ | Military aerodrome traffic zone |
| MAX | Maximum |
| MAY | May |
| MBST | Microburst |
| MCA | Minimum crossing altitude |
| MCTR | Military control zone |
| MCW | Modulated continuous wave |
| MDA | Minimum descent altitude |
| MDD | +Main Duty Department |
| MDF | Medium frequency direction-finding station |
| MDH | Minimum descent height |
| MEA | Minimum en route altitude |
| MEDEVAC | Medical evacuation flight |
| MEHT | Minimum eye-height over threshold (for visual approach slope indicator systems) |
| MET | †Meteorological or meteorology |
| METAR | †Aerodrome routine meteorological report (in meteorological code) |
| MET REPORT | Local routine meteorological report (in abbreviated plain language) |
| MF | Medium frequency (300 to 3 000 KHZ) |
| MHA | Minimum holding 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 |
| MI | +Ministry of the Interior |
| MID | Mid-point (related to RVR) |
| MIFG | Shallow fog |
| MIL | Military |
| MIN | *Minutes |
| MIS | Missing … (transmission identification) (to be used in AFS as a procedure signal) |
| MKR | Marker radio beacon |
| MLS | Microwave landing system |
| MM | Middle marker |
| MNH | Middle latitudes northern hemisphere |
| MMO | +Main Meteorological Office |
| MNM | Minimum |
| MNPS | Minimum navigation performance specifications |
| MNT | Monitor or monitoring or monitored |
| MNTN | Maintain |
| MOA | Military operating area |
| MOC | Minimum obstacle clearance (required) |
| MOCA | Minimum obstacle clearance altitude |
| MOD | Moderate (used to indicate the intensity of weather phenomena, interference or static reports e.g. MODRA = moderate rain) |
| MON | Above mountains |
| MON | Monday |
| MOPS | †Minimum operational performance standards |
| MOV | Move or moving or movement |
| MPS | Metres per second |
| MRA | Minimum reception altitude |
| MRG | Medium range |
| MRP | ATS MET reporting point |
| MS | Minus |
| MSA | Minimum sector altitude |
| MSAS | (to be pronounced “EM-SAS”) Multifunctional transport satellite (MTSAT) satellite-based augmentation system |
| MSAW | Minimum safe altitude warning |
| MSG | Message |
| MSH | Middle latitudes southern hemisphere |
| 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 |
| MT | Mountain |
| MTOM | Maximum take-off mass |
| MTMA | +Military TMA |
| MTOW | +Maximum take-off weight |
| MTSAT | +Multifunctional transport satellite |
| MTU | Metric units |
| MTW | Mountain waves |
| MVA | +Minimum vectoring altitude |
| MVDF | Medium and very high frequency direction-finding stations (at the same location) |
| MWO | Meteorological watch office |
| 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 GLOSSARY OF TERMS | |
| N | No distinct tendency (in RVR during previous 10 minutes) |
| N | North or Northern latitude |
| NADP | Noise Abatement Departure Procedure |
| NAS | +National Ambulance Service |
| NASARS | +National Air Search and Rescue System |
| NASC | †National AIS system centre |
| NAT | North Atlantic |
| NATO | +North Atlantic Treaty Organisation |
| NAV | Navigation |
| NAVAID | Navigation aid |
| NB | Northbound |
| NBFR | Not before |
| NC | No change |
| NCD | No cloud detected (used in automated METAR/SPECI) |
| NDB | Non-directional radio beacon |
| NDGDM | +National Directorate General for Disaster Management |
| NDV | No directional variations available (used 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 to you |
| NLA | +National Light Aviation |
| NM | Nautical miles |
| NML | Normal |
| NN | No name, unnamed |
| NNE | North-north-east |
| NNW | North-north-west |
| NO | No (negative) (to be used in AFS as a procedure signal) |
| NOF | International NOTAM office |
| NON | +Designation of non-modulated |
| NPH | +National Police Headquarters |
| NONSTD | Non-standard |
| NOSIG | †No significant change (used in trend-type landing forecasts) |
| NONFUA | +Not subject to Flexible use of airspace |
| NOTAM | †A 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 |
| NOZ | ‡Normal operating zone |
| NPA | Non-precision approach |
| NPZ | +Non-standard Planning Zone |
| NR | Number |
| NRH | No reply heard |
| NS | Nimbostratus |
| NS | +Non-Scheduled |
| NSC | Nil significant cloud |
| NSE | Navigation system error |
| NSW | Nil significant weather |
| NTL | National |
| NTZ | ‡No transgression zone |
| NW | North-west |
| NWB | North-westbound |
| 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 GLOSSARY OF TERMS | |
| OAC | Oceanic area control centre |
| OAS | Obstacle assessment surface |
| OAT | +Operational Air Traffic |
| 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 |
| OCNL | Occasional or occasionally |
| OCS | Obstacle clearance surface |
| OCT | October |
| OFZ | Obstacle free zone |
| OGN | Originate (to be used in AFS as a procedure signal) |
| OHD | Overhead |
| OIS | Obstacle identification surface |
| OK | *We agree or It is correct (to be used in AFS as a procedure signal) |
| OL | +Operating License - according to EC Regulation 1008/2008 |
| OLDI | †On-line data interchange |
| OM | Outer marker |
| OPA | Opaque, white type of ice formation |
| OPC | Control indicated is operational control |
| OPMET | †Operational meteorological (information) |
| OPN | Open or opening or opened |
| OPR | Operator or operate or operative or operating or operational |
| OPS | †Operations |
| O/R | On request |
| ORD | Order |
| OSV | Ocean station vessel |
| OTP | On top |
| OTS | Organized track system |
| OUBD | Outbound |
| 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 GLOSSARY OF TERMS | |
| P | Maximum value of wind speed or runway visual range ... (followed by figures in METAR/SPECI and TAF) |
| P | +Private |
| P | Prohibited area ... (followed by identification) |
| 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 ... (followed by name/title) |
| PAX | Passenger(s) |
| PBC | Performance-based communication |
| PBN | Performance-based navigation |
| PBS | Performance-based surveillance |
| PCD | Proceed or proceeding |
| PCL | Pilot-controlled lighting |
| PCN | Pavement classification number |
| PCT | Per cent |
| PDC | ‡Pre-departure clearance |
| PDC | +Parking and Docking Chart |
| +Portable Document Format | |
| PDG | Procedure design gradient |
| PER | Performance |
| PERM | Permanent |
| PFP | Preliminary flight plan |
| PIB | Pre-flight information bulletin |
| PJE | Parachute jumping exercise |
| PL | Ice pellets |
| PLA | Practice low approach |
| PLVL | Present level |
| PN | Prior notice required |
| PNR | Point of no return |
| PO | Dust/sand whirls (dust devils) |
| P2 | +Prognostic chart for 200 HPA |
| P3 | +Prognostic chart for 300 HPA |
| P5 | +Prognostic chart for 500 HPA |
| P7 | +Prognostic chart for 700 HPA |
| P85 | +Prognostic chart for 850 HPA |
| Psw | +Prognostic chart of significant weather |
| PTrVM | +Prognostic tropopause and maximum wind chart |
| POB | Persons on board |
| PON | +Pulse modulation, designation of emissions |
| POSS | Possible |
| PPI | Plan position indicator |
| PPR | Prior permission required |
| PPSN | Present position |
| PRFG | Aerodrome partially covered by fog |
| PRI | Primary |
| PRKG | Parking |
| PRM | +Persons with reduced mobility |
| PROB | †Probability |
| PROC | Procedure |
| PROP | Propeller |
| PROV | Provisional |
| PRP | Point-in-space reference point |
| PS | Plus |
| PSG | Passing |
| PSN | Position |
| PSP | Pierced steel plank |
| PSR | ‡Primary surveillance radar |
| PSYS | Pressure system(s) |
| PTN | Procedure turn |
| PTS | Polar track structure |
| 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 GLOSSARY OF TERMS | |
| QDL | Do you intend to to ask me for a series of bearings? or I intend to ask for a series of bearings (to be used in radiotelegraphy as a Q Code) |
| 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) |
| QJH | Shall I run my test tape/a test sentence? or Run your test tape/a test sentence (to be used in AFS as a Q Code) |
| QNH | Altimeter sub-scale setting to obtain elevation when on the ground |
| QSP | Will you relay to … free of charge? or I will relay to … free of charge (to be used in AFS as a Q Code) |
| QTA | Shall I cancel telegram number … ? or Cancel telegram number … (to be used in AFS as a Q Code) |
| QTE | True bearing |
| QTF | Will you give me the position of my station according to the bearings taken by the D/F stations which you control? or The position of your station according to the bearings taken by the D/F stations that I control was … latitude …longitude (or other indication of position), class … at … hours (to be used in radiotelegraphy as a Q Code) |
| QUAD | Quadrant |
| QUJ | Will you indicate the TRUE track to reach you? or The TRUE track to reach me is … degrees at … hours (to be used in radiotelegraphy as a Q Code) |
| 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 GLOSSARY OF TERMS | |
| R | ... Right (preceded by runway designator number to identify a parallel runway) |
| R | Rate of turn |
| R | Red |
| R | Radial from VOR ... (followed by three figures) |
| R | Restricted area ... (followed by identification) |
| R | Runway ... (followed by figures in the METAR/SPECI) |
| R | *Received (acknowledgement of receipt) (to be used in AFS as a procedure signal) |
| RA | Rain |
| RA | Resolution advisory |
| RAC | Rules of the air and air traffic services |
| RAD | +Route Availability Document |
| RAG | Ragged |
| RAG | Runway arresting gear |
| RAI | Runway alignment indicator |
| RAIM | †Receiver autonomous integrity monitoring |
| RASC | †Regional AIS system centre |
| RASS | Remote altimeter setting source |
| RB | Rescue boat |
| RCA | Reach cruising altitude |
| RCC | Rescue coordination centre |
| RCF | Radiocommunication failure (message type designator) |
| RCH | Reach or reaching |
| RCL | Runway centre line |
| RCLL | Runway centre line light(s) |
| RCLR | Recleared |
| RCP | ‡Required communication performance |
| RCR | +Runway Condition Report |
| RDH | Reference datum height |
| RDL | Radial |
| RDO | Radio |
| RDOACT | Radioactive |
| RE | Recent (used to qualify weather phenomena e.g. RERA = recent rain) |
| REA | +Ready message |
| 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 |
| RERTE | Re-route |
| RESA | Runway end safety area |
| RF | Constant radius arc to a fix |
| RFC | +Radio facility chart |
| RFFS | Rescue and fire fighting services |
| RFP | +Replacement Flight Plan |
| RG | Range (lights) |
| RHC | Right-hand circuit |
| RIF | Reclearance in flight |
| RIME | †Rime (used in aerodrome warnings) |
| RITE | +Right (direction of turn) |
| RL | Report leaving |
| RLA | Relay to |
| RLCE | Request level change en route |
| RLLS | Runway lead-in lighting system |
| RLNA | Request level not available |
| RMAC | +Radar minimum altitude chart |
| RMK | Remark |
| RMZ | +Radio Mandatory Zone |
| RNAV | †(to be pronounced "AR-NAV") Area navigation |
| RNG | Radio range |
| RNP | ‡Required navigation performance |
| ROBEX | †Regional OPMET bulletin exchange (scheme) |
| ROC | Rate of climb |
| ROD | Rate of descent |
| RON | Receiving only |
| RPDS | Reference path data selector |
| RPI | ‡Radar position indicator |
| RPL | Repetitive flight plan |
| RPLC | Replace or replaced |
| RPS | Radar position symbol |
| RPT | *Repeat or I repeat (to be used in AFS as a procedure signal) |
| RQ | *Request (to be used in AFS as a procedure signal) |
| RQMNTS | Requirements |
| RQP | Request flight plan (message type designator) |
| RQS | Request supplementary flight plan (message type designator) |
| RR | Report reaching |
| RRA | (or RRB, RRC... etc. in sequence) Delayed meteorological message (message type designator) |
| RSC | Rescue sub-centre |
| RSCD | Runway surface condition |
| RSP | Responder beacon |
| RSP | ‡Required surveillance performance |
| RSR | En-route surveillance radar |
| RSS | Root sum square |
| RTD | Delayed (used to indicate delayed meteorological message; message type designator) |
| RTE | Route |
| RTF | Radiotelephone |
| RTG | Radiotelegraph |
| RTHL | Runway threshold light(s) |
| RTN | Return or returned or returning |
| RTODAH | Rejected take-off distance available, helicopter |
| RTS | Return to service |
| RTT | Radioteletypewriter |
| RTZL | Runway touchdown zone light(s) |
| RUT | Standard regional route transmitting frequencies |
| RV | Rescue vessel |
| RVA | Radar vectoring area |
| RVR | Runway visual range |
| RVSM | Reduced vertical separation minimum (300 m (1 000 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 GLOSSARY OF TERMS | |
| S | +Scheduled |
| S | South or Southern latitude |
| S | State of the sea ... (followed by figures in METAR/SPECI) |
| S6 | +6-hourly surface synoptic chart |
| SA | Sand |
| SALS | Simple approach lighting system |
| SAN | Sanitary |
| 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) |
| SATVOICE | †Satellite voice communication |
| SB | Southbound |
| SBAS | (to be pronounced “ESS-BAS”) Satellite-based augmentation system |
| SC | Stratocumulus |
| SCR | +Schedule Clearance Request |
| SCT | Scattered |
| SD | Standard deviation |
| SDBY | Stand by |
| SDF | Step down fix |
| SE | South-east |
| SEA | Sea (used in connection with sea-surface temperature and state of the sea) |
| SEB | South-eastbound |
| SEC | Seconds |
| SECN | Section |
| SECT | Sector |
| SECSI FRA | +South East Common Sky Initiative Free Route Airspace |
| SEE FRA | +South-East Europe Free Route Airspace |
| SELCAL | †Selective calling system |
| SEP | September |
| SER | Service or servicing or served |
| SERA | +Standardised European Rules of the Air |
| SEV | Severe (used to qualify icing and turbulence reports) |
| SFC | Surface |
| SFT | +Surface Friction Tester |
| 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 (3 000 to 30 000 MHZ) |
| SI | International system of units |
| SID | Standard instrument departure |
| SIF | Selective identification feature |
| SIG | Significant |
| SIGMET | †Information concerning en-route weather and other phenomena in the atmosphere that may affect the safety of aircraft operations |
| SIMUL | Simultaneous or simultaneously |
| SIWL | Single isolated wheel load |
| SKED | Schedule or scheduled |
| SLAP | +Slot allocation procedure |
| SLP | Speed limiting point |
| SLT | +Slot allocation message |
| SLW | Slow |
| SMA | +Schedule Movement Advice |
| 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 |
| SOC | Start of climb |
| SPECI | †Aerodrome special meteorological report (in meteorological code) |
| SPECIAL | †Local special meteorological report (in abbreviated plain language) |
| SPI | Special position indicator |
| SPL | Supplementary flight plan (message type designator) |
| SPOC | SAR point of contact |
| SPOT | †Spot wind |
| SQ | Squall |
| SQL | Squall line |
| SR | Sunrise |
| SRA | Surveillance radar approach |
| SRE | Surveillance radar element of precision approach radar system |
| SRG | Short range |
| SRR | Search and rescue region |
| SRQ | +Slot request message |
| SRY | Secondary |
| SS | Sandstorm |
| SS | Sunset |
| SSB | Single sideband |
| SSE | South-south-east |
| SSIM | +Standard Schedules Information Manual |
| SSR | Secondary surveillance radar |
| SST | Supersonic transport |
| SSW | South-south-west |
| ST | Stratus |
| STA | Straight-in approach |
| STANAG | +Standardization Agreement |
| STAR | †Standard instrument arrival |
| STD | Standard |
| STF | Stratiform |
| STN | Station |
| STNR | Stationary |
| STOL | Short take-off and landing |
| STS | Status |
| STWL | Stopway light(s) |
| SUBJ | Subject to |
| SUN | Sunday |
| SUP | Supplement (AIP supplement) |
| SUPPS | Regional supplementary procedures |
| SVC | Service (message type only) |
| SVCBL | Serviceable |
| SW | South-west |
| SWB | South-westbound |
| SWH | +High Level Significant Weather Chart (FL 250 - FL 450) |
| SWL | +Low Level Significant Weather Chart (Surface - FL 100) |
| SWM | +Medium Level Significant Weather Chart (FL 100 - FL 250) |
| SWX | Space weather |
| SWXC | Space weather centre |
| 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 GLOSSARY OF TERMS | |
| T | Temperature |
| T | ... True (preceded by a bearing to indicate reference to True North) |
| TA | Traffic advisory |
| TA | Transition altitude |
| TAA | Terminal arrival altitude |
| TACAN | †UHF tactical air navigation aid |
| TAF | †Aerodrome forecast (in meteorological code) |
| TA/H | Turn at an altitude/height |
| TAIL | †Tail wind |
| TAR | Terminal area surveillance radar |
| TAS | True airspeed |
| TAX | Taxiing or taxi |
| TC | Tropical cyclone |
| TCA | +Area of responsibility of TMA sector |
| TCAC | Tropical cyclone advisory centre |
| TCAS | +Traffic Collision Avoidance System |
| TCAS RA | †(to be pronounced “TEE-CAS-AR-AY”) Traffic alert and collision avoidance system resolution advisory |
| TCH | Threshold crossing height |
| TCO | +Third Country Operators |
| TCP | +Transfer of control point |
| TCU | Towering cumulus |
| TDA | +Area or responsibility of BUDAPEST DIRECTOR |
| TDO | Tornado |
| TDZ | Touchdown zone |
| TECR | Technical reason |
| TEL | Telephone |
| TEMPO | †Temporary or temporarily |
| TF | Track to fix |
| TFC | Traffic |
| TGL | Touch-and-go landing |
| TGL | +Temporary Guidance Leaflet |
| TGS | Taxiing guidance system |
| THR | Threshold |
| THRU | Through |
| THU | Thursday |
| TIBA | †Traffic information broadcast by aircraft |
| TIL | †Until |
| TIP | Until past ... (followed by place) |
| TIZ | +Traffic Information Zone |
| TKOF | Take-off |
| TL | Till ... (followed by time by which weather change is forecast to end) |
| 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 ... (followed by place) |
| TOBT | +Target Off Block Time |
| TOC | Top of climb |
| TODA | Take-off distance available |
| TODAH | Take-off distance available, helicopter |
| TOP | †Cloud top |
| TORA | Take-off run available |
| TOX | Toxic |
| TP | Turning point |
| TR | Track |
| TRA | Temporary Reserved Airspace |
| TRANS | Transmits or transmitter |
| TREND | †Trend forecast |
| TRCC | +Terminal Radar Control Centre |
| TRG | Training |
| 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 |
| TSB | +Transportation Safety Bureau |
| TSUNAMI | †Tsunami (used in aerodrome warnings) |
| TT | Teletypewriter |
| TUE | Tuesday |
| TURB | Turbulence |
| T-VASIS | †(to be pronounced “TEE –VASIS”) T visual approach slope indicator system |
| TVOR | Terminal VOR |
| TWR | Aerodrome control tower or aerodrome control |
| TWY | Taxiway |
| TWYL | +Taxiway-link |
| TX | Maximum temperature ... (followed by figures in TAF) |
| TXL | Taxilane |
| TXT | *Text (when the abbreviation is used to request a repetition, 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 GLOSSARY OF TERMS | |
| U | Upward (tendency in RVR during previous 10 minutes) |
| U/S | Unserviceable |
| U2 | +200 HPA chart |
| U25 | +250 HPA chart |
| U3 | +300 HPA chart |
| U4 | +400 HPA chart |
| U5 | +500 HPA chart |
| U7 | +700 HPA chart |
| U85 | +850 HPA chart |
| UA | Unmanned aircraft |
| UAB | Until advised by... |
| UAC | Upper area control centre |
| UAR | Upper air route |
| UAS | Unmanned aircraft system |
| UDF | Ultra high frequency direction-finding station |
| UFN | Until further notice |
| UHDT | Unable higher due traffic |
| UHF | Ultra high frequency (300 to 3 000 MHZ) |
| UIC | Upper information centre |
| UIR | Upper flight information region |
| ULM | Ultra light motorized aircraft |
| ULR | Ultra long range |
| UNA | Unable |
| UNAP | Unable to approve |
| UNL | Unlimited |
| UNREL | Unreliable |
| UP | Unidentified precipitation (used in automated METAR/SPECI) |
| USD | +US dollars |
| UTA | Upper control area |
| UTC | Coordinated Universal Time |
| UTM | +Universal Transverse Mercator |
| 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 GLOSSARY OF TERMS | |
| V | ... Variations from the mean wind direction ... (preceded and followed by figures in METAR/SPECI, e.g. 350V070) |
| VA | Heading to an altitude |
| VA | Volcanic ash |
| VAAC | Volcanic ash advisory centre |
| VAC | Visual approach chart ... (followed by name/title) |
| VAL | In valleys |
| VAN | Runway control van |
| VAR | Magnetic variation |
| VAR | Visual-aural radio range |
| VASIS | Visual approach slope indicator systems |
| VAT | +Value-added tax |
| VC | Vicinity of the aerodrome ... (followed by FG = fog, FC = funnel cloud, SH = shower, 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. VC FG = vicinity fog) |
| VCY | Vicinity |
| VDF | Very high frequency direction-finding station |
| VDL | +VHF Data Link |
| VER | Vertical |
| VFR | Visual flight rules |
| VHF | Very high frequency (30 to 300 MHZ) |
| VHO | +Veterinary Hygiene Office |
| VI | Heading to an intercept |
| VIP | Very important person |
| VIS | Visibility |
| VLF | Very low frequency (3 to 30 KHZ) |
| VLR | Very long range |
| VM | Heading to a manual termination |
| VMC | Visual meteorological conditions |
| VNAV | †(to be pronounced “VEE-NAV”) Vertical navigation |
| VOL | Volume ... (followed by I, II ...) |
| VOLMET | †Meteorological information for aircraft in flight |
| VOR | VHF omnidirectional radio range |
| VORTAC | VOR and TACAN combination |
| VOT | VOR airborne equipment test facility |
| VPA | Vertical path angle |
| VPT | Visual manoeuvre with prescribed track |
| VRB | Variable |
| VSA | By visual reference to the ground |
| VSP | Vertical speed |
| VSS | +Visual segment surface |
| VTF | Vector to final |
| 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 GLOSSARY OF TERMS | |
| W | West or western longitude |
| W | White |
| W | Sea-surface temperature (followed by figures in METAR/SPECI) |
| WAAS | Wide area augmentation system |
| WAC | World Aeronautical Chart – ICAO 1 : 1 000 000 ... (followed by name/title) |
| WAFC | World area forecast centre |
| WB | Westbound |
| WBAR | Wing bar lights |
| WD | +Working day |
| WDI | Wind direction indicator |
| WDSPR | Widespread |
| WE | +Weekend |
| WED | Wednesday |
| WEF | With effect from or effective from |
| WGS-84 | World Geodetic System - 1984 |
| WHI | +White |
| WI | Within |
| WID | Width or wide |
| WIE | With immediate effect or effective immediately |
| WILCO | †Will comply |
| WIND | Wind |
| WIP | Work in progress |
| WKN | Weaken or weakening |
| WMO | +World Meteorological Organization |
| WNW | West-north-west |
| WO | Without |
| WPT | Way-point |
| WRNG | Warning |
| WS | Wind shear |
| WSG | +Worldwide Slot Guidelines |
| WSPD | Wind speed |
| WSW | West-south-west |
| WT | Weight |
| WTSPT | Waterspout |
| WWW | Worldwide 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 GLOSSARY OF TERMS | |
| X | Cross |
| XBAR | Crossbar (of approach lighting system) |
| XNG | Crossing |
| XS | Atmospherics |
| 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 GLOSSARY OF TERMS | |
| Y | Yellow |
| YCZ | Yellow caution zone (runway lighting) |
| YEL | +Yellow |
| YES | *Yes (affirmative) (to be used in AFS as a procedure signal) |
| YR | Your |
| 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 GLOSSARY OF TERMS | |
| Z | Coordinated Universal Time (in meteorological messages) |