*Abbreviations marked with an asterisk (*) are either different from or are not contained in ICAO Doc 8400
| 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 | |
| ...C | Centre (preceded by runway designation number to identify a parallel runway) |
| 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 | |
| A | Amber |
| A/A | Air-to-air |
| A/G | Air-to-ground |
| AAL | Above aerodrome level |
| ABM | Abeam |
| ABN | Aerodrome deacon |
| ABT | About |
| AC | Altocumulus |
| ACAS | Airborne collision avoidance system |
| ACC | Area control centre or area control |
| ACCID | Notification of an aircraft accident |
| ACFT | Aircraft |
| ACK | Acknowledge |
| ACL | Altimeter check location |
| 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-B | Automatic dependent surveillance-broadcast |
| ADS-C | Automatic dependent surveillance-contract |
| ADSU | Automatic dependent surveillance unit |
| 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 |
| AGA | Aerodromes, air routes and ground aids |
| AGL | Above ground level |
| AGN | Again |
| AIC | Aeronautical information circular |
| 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) |
| ALS | Approach lighting system |
| ALT | Altitude |
| ALTN | Alternate or alternating (light alternates in colour) |
| ALTN | Alternate (aerodrome) |
| AMA | Area minimum altitude |
| 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) |
| ANS | Answer |
| AOC | Aerodrome obstacle chart |
| AP | Airport |
| 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 |
| 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 |
| ASC | Ascend to or ascending to |
| ASDA | Accelerate-stop distance available |
| ASE | Altimetry system error |
| ASPH | Asphalt |
| ATA | Actual time of arrival |
| ATC | Air traffic control (in general) |
| ATCSMAC... | Air traffic control surveillance minimum altitude chart (followed by name/title) |
| ATD | Actual time of departure |
| ATFM | Air traffic flow management |
| ATIS | Automatic terminal information service |
| ATM | Air traffic management |
| ATN | Aeronautical telecommunication network |
| ATP... | At…(followed by time or place) |
| 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 |
| 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 | |
| B | Blue |
| BA | Braking action |
| BASE | Cloud base |
| BCFG | Fog patches |
| BCN | Beacon (aeronautical ground light) |
| BCST | Broadcast |
| BDRY | Boundary |
| BFR | Before |
| BKN | Broken |
| BLDG | Building |
| BLO | Below clouds |
| BLW... | Below… |
| BOMB | Bombing |
| BR | Mist |
| BRF | Short (used to indicate the type of approach desired or required) |
| BRG | Bearing |
| BRKG | Braking |
| BS | Commercial broadcasting station |
| BTL | Between layers |
| BTN | Between |
| BUFR | Binary universal form for the representation of meteorological data |
| . - 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 | Degrees Celsius (Centigrade) |
| CA | Course to an altitude |
| CAAT | The Civil Aviation Authority of Thailand |
| 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 |
| CD | Candela |
| CDN | Coordination (message type designator) |
| CF | Change frequency to… |
| CF | Course to a fix |
| CGL | Circling guidance light(s) |
| CH | Channel |
| CHEM | Chemical |
| CHG | Modification (message type designator) |
| CI | Cirrus |
| CIDIN | Common ICAO data interchange network |
| CIT | Near or over large towns |
| 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 |
| 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 | Continuous |
| COM | Communications |
| CONC | Concrete |
| COND | Condition |
| CONS | Continuous |
| CONST | Construction or constructed |
| CONT | Continue or continued |
| COOR | Coordinate or coordination |
| 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 |
| CRZ | Cruise |
| CS | Call sign |
| CS | Cirrostratus |
| CTA | Control area |
| CTAM | Climb to and maintain |
| CTC | Contact |
| CTL | Control |
| CTN | Caution |
| CTR | Control zone |
| CU | Cumulus |
| CUF | Cumuliform |
| CUST | Customs |
| 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 | |
| D-ATIS | (to be pronounced “DEE-ATIS”) Data link automatic terminal information service |
| D-VOLMET | Data link VOLMET |
| D... | Danger area (followed by identification) |
| DA | Decision Altitude |
| 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) |
| DEC | December |
| DEG | Degrees |
| DEP | Depart or departure |
| 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 touchdown indicator |
| DH | Decision height |
| DIF | Diffuse |
| DIST | Distance |
| DIV | Divert or diverting |
| DLA | Delay (message type designator) |
| DLA | Delay or delayed |
| DLIC | Data link initiation capability |
| DLY | Daily |
| DME | Distance measuring equipment |
| DNG | Danger or dangerous |
| DOM | Domestic |
| DP | Dew point temperature |
| DPT | Depth |
| DR | Dead reckoning |
| DRG | During |
| DS | Duststorm |
| DSB | Double sideband |
| 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 |
| DUR | Duration |
| DVOR | Doppler VOR |
| DW | Dual wheels |
| DX* | Duplex |
| 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 |
| EB | Eastbound |
| EDA | Elevation differential area |
| EET | Estimated elapsed time |
| EFC | Expect further clearance |
| EHF | Extremely high frequency [30 000 to 300 000 MHz] |
| ELBA | Emergency location beacon-aircraft |
| ELEV | Elevation |
| ELR | Extra long range |
| ELT | Emergency locator transmitter |
| EM | Emission |
| EMBD | Embedded in layer (to indicate Cumulonimbus embedded in layer 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 |
| 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 |
| 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 |
| 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 |
| F | Fixed |
| FA | Course from a fix to an altitude |
| FAC | Facilities |
| FAF | Final approach fix |
| FAL | Facilitation of international air transport |
| FAP | Final approach point |
| FAS | Final approach segment |
| FATO | Final approach and take-off |
| FAX | Facsimile transmission |
| FBL | Light (used to qualify icing, turbulence, interference or static reports) |
| FC | Funnel cloud |
| FCST | Forecast |
| FCT | Friction coefficient |
| FDPS | Flight data processing system |
| FEB | February |
| 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 |
| FNA | Final approach |
| FPL | Filed flight plan (message type designator) |
| FPM | Feet per minute |
| FPR | Flight plan route |
| FR | Fuel remaining |
| 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 |
| FTE | Flight technical error |
| FTP | Fictitious threshold point |
| FTT | Flight technical tolerance |
| 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 | Green |
| 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 |
| GBAS | (to be pronounced “GEE-BAS”) Ground-based augmentation system |
| GCA | Ground controlled approach system or ground controlled approach |
| 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 |
| GP | Glide path |
| GPA | Glide path angle |
| GPIP | Glide path intercept point |
| GPS | Global positioning system |
| GPWS | Ground proximity warning system |
| GR | Hail |
| GRAS | (to be pronounced “GRASS”) Ground-based regional augmentation system |
| GRASS | Grass landing area |
| 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 | High pressure area or the centre of high pressure |
| H24 | Continuous day and night service |
| HA | Holding/racetrack to an altitude |
| HAPI | Helicopter approach path indicator |
| HBN | Hazard beacon |
| HDF | High frequency direction-finding station |
| HDG | Heading |
| HEL | Helicopter |
| HF | High frequency [3 000 to 30 0000 kHz] |
| HF | Holding/racetrack to a fix |
| HGT | Height or height above |
| HJ | Sunrise to sunset |
| HLDG | Holding |
| HM | Holding/racetrack to a manual termination |
| HN | Sunset to sunrise |
| HO | Service available to meet operational requirement |
| HOL | Holiday |
| HOSP | Hospital aircraft |
| HPA | Hectopascal |
| HR | Hours |
| HS | Service available during hours of scheduled operations |
| HUD | Head-up display |
| HURCN | Hurricane |
| HVDF | High and very high frequency direction-finding stations (at the same location) |
| HVY | Heavy |
| 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 | |
| IAC | Instrument approach chart (followed by name/title) |
| IAF | Initial approach fix |
| IAO | In and out of clouds |
| IAP | Instrument approach procedure |
| IAR | Intersection of air routes |
| IAS | Indicated airspeed |
| IBN | Identification beacon |
| ICAO | International Civil Aviation Organisation |
| ICE | Icing |
| ID | Identifier or identify |
| IDENT | Identification |
| IF | Intermediate approach fix |
| IFF | Identification friend/foe |
| IFR | Instrument flight rules |
| IGA | International general aviation |
| ILS | Instrument landing system |
| IM | Inner marker |
| IMC | Instrument meteorological conditions |
| IMG | Immigration |
| IMPR | Improve or improving |
| IMT | Immediate or immediately |
| INA | Initial approach |
| INBD | Inbound |
| INC | In cloud |
| INCERFA | Uncertainty phase |
| INFO | Information |
| INOP | Inoperative |
| INP | If not possible |
| INPR | In progress |
| INS | Inches (dimensional unit) |
| INS | Inertial navigation system |
| INSTL | Install or installed or installation |
| INSTR | Instrument |
| INT | Intersection |
| INTER* | Intermittent |
| 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 |
| ITC* | International aeronautical fixed Telecommunication centre |
| 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 | |
| JAN | January |
| 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 | |
| KG | Kilograms |
| KHZ | Kilohertz |
| KIAS | Knots indicated airspeed |
| KM | Kilometres |
| KMH | Kilometres per hour |
| KPA | Kilopascal |
| KT | Knots |
| KW | Kilowatts |
| … - 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 | Low pressure area or the centre of low pressure |
| LAM | Logical acknowledgment (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 |
| LIH | Light intensity high |
| LIL | Light intensity low |
| LIM | Light intensity medium |
| 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 | Loran (long range air navigation system) |
| LOSS | Airspeed or headwind loss |
| LPV | Localizer performance with vertical guidance |
| LRG | Long range |
| LTD | Limited |
| LTP | Landing threshold point |
| LTT | Landline teletypewriter |
| LV | Light and variable (relating to wind) |
| LVE | Leave or leaving |
| LVL | Level |
| LYR | Layer or layered |
| … - 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/W* | Microwave |
| MAA | Maximum authorized altitude |
| MAG | Magnetic |
| MAHF | Missed approach holding fix |
| MAINT | Maintenance |
| MAP | Aeronautical maps and charts |
| MAPT | Missed approach point |
| MAR | At sea |
| MAR | March |
| MAS | Manual A1 Simplex |
| MATF | Missed approach turning fix |
| MAX | Maximum |
| MAY | May |
| MBST | Microburst |
| MCA | Minimum crossing altitude |
| MCW | Modulated continuous wave |
| MDA | Minimum descent altitude |
| MDF | Medium frequency direction-finding station |
| MDH | Minimum descent height |
| MEA | Minimum en-route altitude |
| MEHT | Minimum eye height over threshold (for visual approach slope indicator system) |
| MET | Meteorological or meteorology |
| METAR | Aerodrome routine meteorological report (in meteorological code) |
| MF | Medium frequency [300 to 3000 kHz] |
| 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 |
| MLS | Microwave landing system |
| MM | Middle marker |
| 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”) Multi-functional transport satellite (MTSAT) |
| MSAW | Minimum safe altitude warning |
| MSG | Message |
| MSL | Mean sea level |
| MT | Mountain |
| MTU | Metric units |
| MTW | Mountain waves |
| 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 | |
| M… | Mach number (followed by figures) |
| M… | Minimum value of runway visual range (followed by figures in METAR/SPECI) |
| N | No distinct tendency (in RVR during previous 10 minutes) |
| N | North or northern latitude |
| NAT | North Atlantic |
| NAV | Navigation |
| NB | Northbound |
| NBFR | Not before |
| NC | No change |
| NDB | Non-directional radio beacon |
| NE | North-east |
| NEB | North-eastbound |
| NEG | No or negative or permission not granted or that is not correct |
| NGT | Night |
| NIL | None or l have nothing to send to you |
| NM | Nautical miles |
| NML | Normal |
| NN | No name, unnamed |
| NNE | North-north-east |
| NNW | North-north-west |
| NOF | International NOTAM office |
| 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 |
| NOV | November |
| NR | Number |
| NRH | No reply heard |
| NS | Nimbostratus |
| NSC | Nil significant cloud |
| NSE | Navigation system error |
| 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 | |
| O/R | On request |
| OAC | Oceanic area control center |
| OAS | Obstacle assessment surface |
| OBS | Observe or observed or observation |
| OBSC | Obscure or obscured or obscuring |
| OBST | Obstacle |
| OCA | Obstacle Clearance Altitude or Height |
| OCA | Oceanic control area |
| OCC | Occulting (light) |
| OCH | Obstacle Clearance Height |
| OCL | Obstacle clearance limit |
| OCNL | Occasional or occasionally |
| OCS | Obstacle clearance surface |
| OCT | October |
| OFZ | Obstacle free zone |
| OHD | Overhead |
| OIS | Obstacle identification surface |
| OLDI | On-line data interchange |
| OM | Outer marker |
| OPA | Opaque, white type of ice formation |
| OPC | The 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 |
| ORD | Indication of an 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 | |
| PA | Precision approach |
| PACT… | Precision approach terrain chart (followed by name/title) |
| PALS | Precision approach lighting system (specify category) |
| PANS | Procedures for air navigation services |
| PAPI | Precision approach path indicator |
| PAR | Precision approach radar |
| PARL | Parallel |
| PAX | Passenger(s) |
| PBN | Performance-based navigation |
| PCD | Proceed or proceeding |
| PCL | Pilot-controlled lighting |
| PCN | Pavement classification number |
| PDC | Pre-departure clearance |
| PDG | Procedure design gradient |
| PER | Performance |
| PERM | Permanent |
| PIB | Pre-flight information bulletin |
| PJE | Parachute jumping exercise |
| PL | Ice pellets |
| PLA | Practice low approach |
| PLN | Flight plan |
| PLVL | Present level |
| PN | Prior notice required |
| PNR | Point of no return |
| PO | Dust devils |
| POB | Persons on board |
| POSS | Possible |
| PPI | Plan position indicator |
| PPR | Prior permission required |
| PPSN | Present position |
| PRFG | Aerodrome partially covered by fog |
| PRI | Primary |
| PRKG | Parking |
| PROB | Probability |
| PROC | Procedure |
| PROV | Provisional |
| 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 | |
| P… | Prohibited area (followed by identification) |
| 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 |
| QUAD | Quadrant |
| … - 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 | Rate of turn |
| R | Red |
| RA | Rain |
| RA | Resolution advisory |
| RAC | Rules of the air and air traffic services |
| RAG | Ragged |
| RAG | Runway arresting gear |
| RAI | Runway alignment indicator |
| RAIM | Receiver autonomous integrity monitoring |
| RAPCON* | Radar approach control |
| RASC | Regional AIS system centre |
| RASS | Remote altimeter setting source |
| RB | Rescue boat |
| RCA | Reach cruising altitude |
| RCAG* | Remote control air ground |
| RCC | Rescue co-ordination centre |
| RCF | Radio communication failure (message type designator) |
| RCH | Reach or reaching |
| RCL | Runway centre line |
| RCLL | Runway centre line light(s) |
| RCLR | Recleared |
| RCP | Required communication performance |
| RDH | Reference datum height (for ILS) |
| RDL | Radial |
| RDO | Radio |
| RE | Recent (used to qualify weather phenomena such as rain, e.g. recent rain = RERA) |
| REC | Receive or receiver |
| REDL | Runway edge light(s) |
| REF | Reference to…or refer to… |
| REG | Registration |
| REIL* | Runway end identifier light(s) |
| 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 |
| RG | Range (lights) |
| RHC | Right-hand circuit |
| RIF | Reclearance in flight |
| RITE | Right (direction of turn) |
| RL | Report leaving |
| RLA | Relay to |
| RLCE | Request level change en route |
| RLLS | Runway lead-in lighting system |
| RMK | Remark |
| 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 |
| RQNMTS | Requirements |
| 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 |
| RSR | En-route surveillance radar |
| RTAF* | Royal Thai Air Force |
| 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 |
| RTN* | Royal Thai Navy |
| RTODAH | Rejected take-off distance available, helicopter |
| RTS | Return to service |
| RTT | Radio teletype writer |
| RTZL | Runway touchdown zone light(s) |
| RUT | Standard regional route transmitting frequencies |
| RV | Rescue vessel |
| 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 | |
| R… | Restricted area (followed by identification) |
| R… | Runway (followed by figures in METAR/SPECI) |
| S | South or southern latitude |
| SA | Sand |
| SALS | Simple approach lighting system |
| SAN | Sanitary |
| SAP | As soon as possible |
| SAR | Search and rescue |
| SARPS | Standard and Recommended Practices (ICAO) |
| SAT | Saturday |
| SATCOM | Satellite communication |
| SB | Southbound |
| SBAS | (to be pronounced “ESS-BAS”) Satellite-based augmentation system |
| SC | Stratocumulus |
| SCT | Scattered |
| SD | Standard deviation |
| SDBY | Stand by |
| SDF | Standard deviation Stepdown fix |
| SE | South-east |
| SEB | South-eastbound |
| SEC | Seconds |
| SECN | Section |
| 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 |
| SGL | Signal |
| SHF | Super high frequency [3 000 to 30 000 MHz] |
| SH… | Shower (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) |
| SI | International system of units |
| SID | Standard instrument departure |
| SIF | Selective identification feature |
| SIGMET | Information concerning en-route weather phenomena which may affect the safety of aircraft operations |
| SIMUL | Simultaneous or simultaneously |
| SIWL | Single isolated wheel load |
| SKED | Schedule or scheduled |
| SLP | Speed limiting point |
| SLW | Slow |
| 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 | Aviation selected special weather report (in aeronautical meteorological (code) |
| SPECIAL | 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 |
| SR | Sunrise |
| SRA | Surveillance radar approach |
| SRE | Surveillance radar element of precision approach radar system |
| SRG | Short range |
| SRR | Search and rescue region |
| SRY | Secondary |
| SS | Sandstorm |
| SS | Sunset |
| SSB | Single sideband |
| SSE | South-south-east |
| SSR | Secondary surveillance radar |
| SST | Supersonic transport |
| SSW | South-south-west |
| ST | Stratus |
| STA | Straight in approach |
| 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 |
| SUPPS | Regional supplementary procedures |
| SVC | Service message |
| SVCBL | Serviceable |
| SW | South-west |
| SWB | South-westbound |
| SWY | Stopway |
| SX* | Simplex |
| 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 | |
| S… | State of the sea (followed by figures in METAR/SPECI) |
| T | Temperature |
| T-VASIS | (to be pronounced”TEE-VASIS”) T visual approach slope indicator system |
| TA | Traffic advisory |
| TA | Transition altitude |
| TA/H | Turn at an altitude/height |
| TAA | Terminal arrival altitude |
| TACAN | UHF tactical air navigation aid |
| TAF | Aerodrome forecast |
| TAIL | Tail wind |
| TAR | Terminal area surveillance radar |
| TAS | True airspeed |
| TAX | Taxiing or taxi |
| TC | Tropical cyclone |
| TCAC | Tropical cyclone advisory centre |
| TCAS RA | (to be pronounced “TEE-CAS-AR-AY” Traffic alert and collision avoidance system resolution advisory |
| TCH | Threshold crossing height |
| TCU | Towering cumulus |
| 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 |
| TGS | Taxiing guidance system |
| THR | Threshold |
| THRU | Through |
| THU | Thursday |
| TIL | Until |
| TIP | Until past…(followed by place) |
| TKOF | Take-off |
| TLOF | Touchdown and lift-off area |
| TL… | Till (followed by time be which weather change is forecast to end) |
| TMA | Terminal control area |
| TNA | Turn altitude |
| TNH | Turn height |
| TN… | Minimum temperature (followed be figures in TAF) |
| 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 |
| TO… | To…(followed by place) |
| TP | Turning point |
| TR | Track |
| TRA | Temporary reserved airspace |
| TRANS | Transmits or transmitter |
| TRL | Transition level |
| TROP | Tropopause |
| TS | Thunderstorm (in aerodrome reports and forecasts, TS used alone means thunder heard but no precipitation at the aerodrome) |
| TSUNAMI | Tsunami (used in aerodrome warnings) |
| 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. TSRANSN=thunderstorm with rain and snow) |
| TT | Teletypewriter |
| TUE | Tuesday |
| TURB | Turbulence |
| TVOR | Terminal VOR |
| TWR | Aerodrome control tower or aerodrome control |
| TWY | Taxiway |
| TWYL | Taxiway-link |
| TX… | Maximum temperature (followed by figures in TAF) |
| 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 |
| 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 |
| ULR | Ultra long range |
| UNA | Unable |
| UNAP | Unable to approve |
| UNL | Unlimited |
| UNREL | Unreliable |
| UP | Unidentified precipitation (used in automated METAR/SPECI) |
| UTA | Upper control area |
| UTC | Coordinated Universal Time |
| … - 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 | |
| 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 |
| VCY | Vicinity |
| 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=dust storm, SS=sandstorm, TS=thunderstorm or VA=volcanic ash, e.g. VCFG=vicinity fog) |
| VDF | Very high frequency direction-finding station |
| VER | Vertical |
| VFR | Visual flight rules |
| VHF | Very high frequency [30 to 300 MHz] |
| 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 pronounce VEE-NAV) Vertical navigation |
| 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 |
| VRB | Variable |
| VSA | By visual reference to the ground |
| VSP | Vertical speed |
| VTF | Vector to final |
| VTOL | Vertical take-off and landing |
| VV… | Vertical visibility (followed by figures in METAR/SPECI and TAF) |
| 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 |
| 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 |
| WAFC | World area forecast centre |
| WB | Westbound |
| WBAR | Wing bar lights |
| WBI | Wind direction indicator |
| WDSPR | Widespread |
| WED | Wednesday |
| WEF | With effect from or effective from |
| WGS-84 | World Geodetic System-1984 |
| WI | Within |
| WID | Width |
| WIE | With immediate effect or effective immediately |
| WILCO | Will comply |
| WIP | Work in progress |
| WKN | Weaken or weakening |
| WNW | West-north-west |
| WO | Without |
| WPT | Way-point |
| WRNG | Warning |
| WS | Wind shear |
| WSPD | Wind speed |
| WSW | West-south-west |
| WT | Weight |
| WTSPT | Waterspout |
| WWW | Worldwide web |
| WX | Weather |
| 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) |
| 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 | |
| Y | Yellow |
| YCZ | Yellow caution zone (runway lighting) |
| 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 | |
| Z | Coordinated Universal Time (in meteorological messages) |
| …L | Left (preceded by runway designation number to identify a parallel runway) |
| 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 | |
| …M | Metres (preceded by figures) |
| 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 | |
| …R | Right (preceded by runway designation number to identify a parallel runway) |
| 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 | |
| …V… | Variations from the mean wind direction (preceded and followed by figures in METAR/SPECI, e.g. 350V070) |
| 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 | |