The abbreviations used in AIS publications are as specified in Doc 8400, ICAO Abbreviations and Codes and Doc 8126, Aeronautical Information Services. Additional abbreviations are used to provide for local requirements. Abbreviations marked by an asterisk(*) are either different from or 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 | |
| A | Amber |
| A-CDM | Airport collaborative decision making |
| A/A | Air-to-air |
| A/G | Air-to-ground |
| AAD | Assigned altitude deviation |
| AAL | Above aerodrome level |
| ABM | Abeam |
| ABN | Aerodrome beacon |
| ABT | About |
| ABV | Above |
| AC | Altocumulus |
| ACARS | Aircraft communication addressing and reporting system |
| ACAS | Airborne collision avoidance system |
| ACC | Area control center |
| 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, 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 | Air defence identification zone |
| ADJ | Adjacent |
| ADP | ATFM daily plan |
| ADR | Advisory route |
| ADS | Automatic dependent surveillance |
| ADSU | Automatic dependent surveillance unit |
| ADVS | Advisory service |
| ADZ | Advise |
| AES | Aircraft earth station |
| AFFF** | Aqueous Film Forming Foam |
| AFIL | Flight plan filed in the air |
| AFIS | Aerodrome flight information service |
| AFM | Yes or affirm or affirmative or that is correct |
| AFP | Airspace flow program |
| AFS | Aeronautical fixed service |
| AFT | After.......(time or place) ... |
| AFTN | Aeronautical fixed telecommunication network |
| AGA | Aerodrome, air routes and ground aids |
| AGL | Above ground level |
| AGN | Again |
| AIC | Aeronautical information circular |
| AIDC | Air traffic services inter-facility data communication |
| AIP | Aeronautical information publication |
| AIRAC | Aeronautical information regulation and control |
| AIREP | Air-report |
| AIRMET | Information concerning enroute 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 |
| 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 byname/title and scale) |
| 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 | Approach procedure with vertical guidance |
| APV | Approve or approved or approval |
| ARC | Area chart |
| ARFOR | Area forecast (in aeronautical meteorological code) |
| 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 |
| AT | At (followed by time at which weather change is forecast to occur) |
| AT-VASIS | Abbreviated T visual approach slope indicator system |
| 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 |
| ATP | At... (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 |
| 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 | |
| B | Blue |
| BA | Braking action |
| BARO-VNAV | Barometric Vertical Navigation |
| 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) |
| 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 |
| 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) |
| CAT | Category |
| CAT | Clear air turbulance |
| 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 |
| CCA | (or CCB, CCC...etc. in sequence) Corrected meteorological message (message type designator) |
| CCW* | Counterclockwise |
| CD | Candela |
| CDM | Collaborative decision making meeting |
| CDN | Coordination |
| CF | Change frequency to ... |
| CF(Path Descriptor) | Course to a Fix |
| CG** | Climb gradient |
| CGL | Circling guidance light |
| CH | Channel |
| CHG | Modification (message type designator) |
| CI | Cirrus |
| CIDIN | Common ICAO data interchange network |
| CIT | Near or over large town |
| CIV | Civil |
| CK | Check |
| CL | Centre line |
| CLA | Clear type of ice formation |
| CLBR | Calibration |
| CLD | Cloud |
| CLDT | Calculated landing time |
| CLR | Clear(s) or cleared to ... or clearance |
| CLSD | Close or closed or closing |
| CM | Centimeter |
| 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 |
| COBT | Calculated off-block time |
| COM | Communications |
| CONC | Concrete |
| COND | Condition |
| CONS | Continuous |
| CONST | Construction or constructed |
| CONT | Continue or continued |
| COOR | Coordinate or coordination |
| COORD | Coordinates |
| COP | Change-over-point |
| COR | Correct or corrected or correction(used to indicate corrected meterological message : message type designator) |
| COT | At the coast |
| COV | Cover or covered or covering |
| CPL | Current flight plan (message type designator) |
| CRC | Cyclic redundancy check |
| CRM | Collision risk model |
| CRZ | Cruise |
| CS | Cirrostratus |
| CS | Call sign |
| CTA | Control area |
| CTAM | Climb to and maintain |
| CTC | Contact |
| CTL | Control |
| CTN | Caution |
| CTO | Calculated time over |
| CTOT | Calculated take-off time |
| CTR | Control zone |
| CU | Cumulus |
| CUF | Cumuliform |
| CUST | Customs |
| CVR | Cockpit voice recorder |
| CW | Continuous wave |
| CW* | Clockwise |
| 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 | Downward (tendency in RVR during previous 10 minutes) |
| 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 |
| 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 |
| DENEB | Fog dispersal operations |
| DEP | Depart or departure |
| DEP | Departure (message type designator) |
| DER* | Departure end of the runway |
| DES | Descend to or descending to |
| DEST | Destination |
| DETRESFA | Distress phase |
| DEV | Deviation or deviating |
| DFDR | Digital flight data recorder |
| DFTI | Distance from touchdown indicator |
| DH | Decision height |
| DIF | Diffuse |
| DIST | Distance |
| DIV | Divert or diverting |
| DLA | Delay or delayed or Delay (message type designator) |
| DLA | Delay or delayed |
| DLVRY** | Delivery |
| DME | Distance measuring equipment |
| DNG | Danger or dangerous |
| DOM | Domestic |
| DP | Dew point temperature |
| DPT | Depth |
| DR | Dead reckoning |
| DR... | Low drifting (followed by DU=dust, SA=sand or SN=snow) |
| DRG | During |
| DS | Dust storm |
| 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 |
| 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 | East bound |
| EET | Estimated elapsed time |
| EFC | Expect further clearance |
| EHF | Extremely high frequency (30 000 to 300 000 Mhz) |
| ELBA | Emergency location beacon-aircraft |
| ELDT | Estimated landing time |
| ELEV | Elevation |
| ELR | Extra long range |
| ELT | Emergency locator transmitter |
| EM | Emission |
| EMBD | Embedded in a layer (to indicate cumulonimbus embedded in layers of other clouds) |
| EMERG | Emergency |
| END | Stop-end (related to RVR) |
| ENE | East north east |
| ENG | Engine |
| ENR | En route |
| ENRC | Enroute chart (followed by name/title) |
| 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 |
| ETO | Estimated time over significant point |
| ETOT | Estimated take-off time |
| EV | Every |
| EXC | Except |
| EXER | Exercise 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 | Fixed |
| FAC | Facilities |
| FAF | Final approach fix |
| FAL | Facilitation of international air transport |
| FAP | Final approach point |
| FATO | Final approach and take-off area |
| FAX | Facsimile transmission |
| FBL | Light (used to indicate the intensity of weather phenomena, interference or static reports, e.g. FBL RA=light rain) |
| FC | Funnel cloud(tornado or water spout) |
| FCST | Forecast |
| FCT | Friction coefficient |
| FDPS | Flight data processing system |
| FDR | Flight data recorder |
| FEB | February |
| FEW | Few |
| 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 | From |
| FM | From (Followed by time weather change is forecast to begin) |
| FMC | Flight management computer |
| FMS | Flight management system |
| FMU | Flow management unit |
| 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) |
| FRQ | Frequent |
| FSL | Full stop landing |
| FSS | Flight service station |
| FST | First |
| 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 | Green |
| G/A | Ground-to-air |
| G/A/G | Ground-to-air and air-to-ground |
| GA | Go ahead, resume sending to be used in AFS as a procedure signal |
| GAMET | Area forecast for low-level flights |
| GCA | Ground controlled approach system or ground controlled approach |
| GDP | Ground delay program |
| GEN | General |
| GEO | Geographic or true |
| GES | Ground earth station |
| GLD | Glider |
| GLONASS | Global orbiting navigation satellite system(to be pronounced "GLO-NAS") |
| GMC | Ground movement chart (followed by name/title) |
| GND | Ground |
| GNDCK | Ground check |
| GNSS | Global navigation satellite system |
| GP | Glide path |
| GPS | Global positioning system |
| GR | Hail |
| GRASS | Grass landing area |
| GRF | Global reporting format for assessing and reporting runway surface condition |
| GRID | Processed meteorological data in the form of grid point values expressed in binary form(meteological code) |
| GRVL | Gravel |
| GS | Ground speed |
| GS | Ground stop |
| 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 | |
| H24 | Continuous day and night service |
| HAPI | Helicopter approach path indicator |
| HBN | Hazard beacon |
| HCH | Heliport crossing height |
| HDF | High frequency direction-finding station |
| HDG | Heading |
| HEL | Helicopter |
| HF | High frequency(3 000 to 30 000 kHz) |
| HGT | Height or height above |
| HJ | Sunrise to sunset |
| HLDG | Holding |
| HM(Path Descriptor) | 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 |
| HRP | Heliport reference point |
| HS | Service available during hours of scheduled operations |
| 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. HVY RA=heavy rain) |
| 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 |
| IAR | Intersection of air routes |
| IAS | Indicated air speed |
| IBN | Identification beacon |
| 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 |
| IF*(Path Descriptor) | Initial Fix |
| IFF | Identification friend/foe |
| IFR | Instrument flight rule |
| 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 | Inertial navigation system |
| INSTL | Install or installed or installation |
| INSTR | Instrument |
| INT | Intersection |
| INTL | International |
| INTRG | Interrogator |
| INTRP | Interrupt or interruption or interrupted |
| INTSF | Intensify or intensifying |
| INTST | Intensity |
| IR | Ice on runway |
| ISA | International standard atmosphere |
| 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 | |
| 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 | kilometers |
| KMH | Kilometers per hour |
| KPA | Kilopascal |
| KST | Korean standard time |
| 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 | Left(preceded by runway designation number to identify a parallel runway) |
| L | Locator(see LM, LO) |
| LAM | Logical acknowledgement(message type designator) |
| LAN | Inland |
| LAT | Latitude |
| LDA | Landing distance available |
| LDAH | Landing distance available, helicopter |
| LDG | Landing |
| LDI | Landing direction indicator |
| LEN | Length |
| LF | Low frequency(30 to 300Khz) |
| 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 | 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) |
| LPV | Localizer performance with vertical guidance |
| LR* | Lead radial |
| LRG | Long range |
| LSQ | Line squall |
| LTD | Limited |
| LTT | Landing teletypewriter |
| LV | Light and variable(relating to wind) |
| LVE | Leave or leaving |
| LVL | Level |
| 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 | |
| ...M | Meters(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 |
| MAINT | Maintenance |
| MAP | Aeronautical maps and charts |
| MAPT | Missed approach point |
| MAR | At sea |
| MAR | March |
| MAS | Manual Al simplex |
| MAX | Maximum |
| MAY | May |
| 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 systems) |
| MET | Meteorological or Meteorology |
| METAR | Aerodrome routine meteorological report(in meteorological code) |
| MF | Medium frequency(300 to 3 000 kHz) |
| MHDF | Medium and high frequency direction-finding stations(at the same location) |
| MHVDF | Medium, high and very high frequency direction-finding station(at the same location) |
| MHZ | Megahertz |
| MID | Mid-point(related to RVR) |
| MIFG | Shallow fog |
| MIL | Military |
| MIN | Minute |
| MINT | Minute in trail |
| MIT | Miles in trail |
| 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 | Meters per second |
| MRA | Minimum reception altitude |
| MRG | Medium range |
| MRP | ATS/MET reporting point |
| MS | Minus |
| MSA | Minimum sector altitude |
| MSG | Message |
| MSL | Mean sea level |
| MSSR | Monopulse secondary surveillance radar |
| 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 | |
| N | North or northern latitude |
| N | No distinct tendency(in RVR during previous 10 minutes) |
| NASC | National AIS system center |
| NAT | North Atlantic |
| NAV | Navigation |
| NB | Northbound |
| NBFR | Not before |
| NC | No change |
| NDB | Non-directional radio beacon |
| NE | North-east |
| NEB | North-east bound |
| NEG | No or negative or permission not granted or that is not correct |
| NGT | Night |
| NIL | None or I have nothing to send you |
| NM | Nautical miles |
| NML | Normal |
| NNE | North north east |
| NNW | North north west |
| NOF | International NOTAM office |
| NOSIG | No significant change (Used in trend-type landing forecasts) |
| NOTAM | 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 |
| NOV | November |
| NOZ | Normal operating zone |
| NR | Number |
| NRH | NO reply heard |
| NS | Nimbostratus |
| NSC | Nil significant cloud |
| NSW | Nil significant weather |
| NTL | National |
| NTZ | No transgression zone |
| NW | North west |
| NWB | North west bound |
| 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 | |
| OAS | Obstacle assessment surface |
| OBS | Observe or observed or observation |
| OBSC | Obscure or obscured or obscuring |
| OBST | Obstacle |
| OCA | Obstacle clearance altitude |
| OCC | Occulting(light) |
| OCH | Obstacle clearance height |
| OCNL | Occasional or occasionally |
| OCS | Obstacle clearance surface |
| OCT | October |
| OFZ | Obstacle free zone |
| OHD | Overhead |
| OLDI | On-line data interchange |
| OM | Outer marker |
| OPA | Opaque, white type of ice formation |
| OPMET | Operational meteorological(information) |
| OPN | Open or opening or opened |
| OPR | Operater or operate or operative or operating or operational |
| OPS | Operations |
| O/R | On request |
| OTLK | Outlook(used in SIGMET message for valcanic ash and tropical cyclones) |
| OTP | On top |
| 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 | |
| P... | Prohibited area(followed by identification) |
| PALS | Precision approach lighting system(specify category) |
| PANS | Procedures for air navigation services |
| PAPI | Precision approach path indictor |
| PAR | Precisoin 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 |
| PE | Ice pellets |
| 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/sand whirls(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 | |
| 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 |
| 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 | Red |
| R... | Restricted area(followed by identification) |
| R... | Right(preceded by runway designation number to identify a parallel runway) |
| R... | Runway(followed by figures in METAR/SPECI) |
| RA | Rain |
| RAC | Rules of the air and air traffic services |
| RAFC | Regional area forecast center |
| RAG | Runway arresting gear |
| RAI | Runway alignment indicator |
| RAIM | Receiver autonomous integrity monitoring |
| RASC | Regional AIS system center |
| RB | Rescue boat |
| RCA | Reach cruising altitude |
| RCAM | Runway condition assessment matrix |
| RCC | Rescue coordination center |
| RCF | Radiocommunication failure(message type designator) |
| RCH | Reach or reaching |
| RCL | Runway center line |
| RCLL | Runway center line light(s) |
| RCLR | Recleared |
| RCR | Runway condition report |
| RDH | Reference datum height |
| 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 |
| RENL | Runway end light(s) |
| REP | Report or reporting or reporting point |
| REQ | Request or requested |
| RERTE | Re-route |
| RESA | Runway end safety area |
| 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 |
| RLNA | Request level not available |
| RMK | Remark |
| RNAV | Area navigation |
| RNG | Radio range |
| RNP | Required navigation performance |
| ROBEX | Regional OPMET bulletin exchange (scheme) |
| ROC | Rate of climb |
| ROD | Rate of descent |
| ROFOR | Route forecast(in meteorological code) |
| RON | Receiving only |
| RPI | Radar position indicator |
| RPL | Repetitive flight plan |
| RPLC | Replace or replaced |
| RPS | Radar positon symbol |
| RQMNTS | Requirements |
| RQP | Request flight plan(message type designator) |
| RQS | Request supplementary flight plan(message type designator) |
| RR | Report reaching |
| RRA | Delayed meteorological message (message type designator) |
| RSCD | Runway surface condition |
| RSP | Responder beacon |
| RSR | En-route surveillance radar |
| 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 |
| RVR | Runway visual range |
| RVSM | Reduced vertical seperation minimum(300 m(1 000 ft) between FL290 and FL410) |
| RWY | Runway |
| RWYCC | Runway condition code |
| RX | Receiver |
| 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 | South or Southern latitude |
| SA | Sand |
| SALS | Simple approach lighting system |
| SAN | Sanitary |
| SAP | As soon as possible |
| SAR | Search and rescue |
| SARPS | Standards and Recommended Practices(ICAO) |
| SAT | Saturday |
| SATCOM | Satellite communication |
| SB | Southbound |
| SBAS | Satellite-based augmentation system |
| SC | Stratocumulus |
| SCT | Scattered |
| SDBY | Stand by |
| SDF | Step down Fix |
| SE | South-east |
| SEB | South-east bound |
| SEC | Seconds |
| SECT | Sector |
| SELCAL | Selective calling system |
| SEP | September |
| SER | Service or servicing or served |
| SEV | Severe(used e.g. to qualify icing and turbulence reports) |
| SFC | Surface |
| SG | Snow grains |
| 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) |
| SID | Standard instrument departure |
| SIF | Selective identification feature |
| SIG | Significant |
| SIGMET | Information concerning en-route weather phenomena which may affect the safety of aircraft operation |
| SIGWX | Significant weather |
| SIMUL | Simultaneous or simultaneously |
| SIWL | Single isolated wheel load |
| SKC | Sky clear |
| SKED | Schedule or scheduled |
| SLP | Speed limiting point |
| SLW | Slow |
| SMC | Surface movement control |
| SMR | Surface movement radar |
| SN | Snow |
| SNOWTAM | 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 |
| SPD* | Speed |
| SPECI | Aerodrome special meteorological report(in meteorological code) |
| SPECIAL | Special meteorological report(in abbreviated plan language) |
| SPL | Supplementary flight plan(message type designator) |
| SPOC | SAR point of contact |
| 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 |
| SRY | Secondary |
| SS | Sunset |
| SS | Sandstorm |
| 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 |
| SUP | Supplement(AIP Supplement) |
| SUPPS | Regional supplementary procedure |
| SVC | Service message |
| SVCBL | Serviceable |
| SW | South-west |
| SW | South-westbound |
| 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 |
| TA | Transition altitude |
| TACAN | UHF tactical air navigation aid |
| TAF | Aerodrome forecast(in meteorological code) |
| TAIL | Tail wind |
| TAR | Terminal area surveillance radar |
| TAS | True airspeed |
| TAX | Taxiing or taxi |
| TC | Tropical cyclone |
| TCH | Threshold crossing height |
| TCU | Towering cumulus |
| TDO | Tornado |
| TDZ | Touchdown zone |
| TECR | Technical reason |
| TEL | Telephone |
| TEMPO | Temporary or temporarily |
| TEND | Trend forecast |
| TF(Path Descriptor) | Track to a Fix |
| TFC | Traffic |
| TGL | Touch-and-go landing |
| TGS | Taxiing guidance system |
| THR | Threshold |
| THRU | Through |
| THU | Thursday |
| TIBA | Traffic information broadcast by aircraft |
| TIL | Until |
| TIP | Until past...(place) |
| TKOF | Take off |
| TL... | Till(followed by time by which weather change is forest to end) |
| TLOF | Touchdown and lift-off area |
| TMA | Terminal control area |
| 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 |
| TRL | Transition level |
| TROP | Tropopause |
| TS | Thunderstorm (in aerodrome reports and forecasts, TS used alone means thunder heard but no precipitation as the aerodrome) |
| TS... | Thunderstorm (followed by RA=rain, SN=snow, PE=ice pellets, GR=hail, GS=small hail and/or snow pellets or combinations thereof, e.g. TSRASN=thunderstorm with rain and snow) |
| TT | Teletypewriter |
| TUE | Tuesday |
| TURB | Turbulence |
| T-VASIS | T visual approach slope indicator system |
| TVOR | Terminal VOR |
| TWR | Aerodrome control tower or aerodrome control |
| TWY | Taxiway |
| TWYL | Taxiway-link |
| TX | Transmitter |
| TXL | Taxilane |
| 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 |
| UAB | Until advised by... |
| UAC | Upper area control center |
| UAR | Upper air route |
| 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 fight information region |
| ULR | Ultra long range |
| UNA | Unable |
| UNAP | Unable to approve |
| UNL | Unlimited |
| UNREL | Unreliable |
| 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 | |
| VA | Volcanic ash |
| VAC | Visual approach chart(followed by name/title) |
| VAL | In valleys |
| VAL | Visual approach and landing chart |
| VAN | Runway control van |
| VAR | Magnetic variation |
| VAR | Visual-aural radio range |
| VASIS | Visual approach slope indicator system |
| 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. VCFG = vicinity fog) |
| VCY | Vicinity |
| VDF | Very high frequency direction-finding station |
| VER | Vertical |
| VFR | Visual flight rules |
| VHF | Very high frequency(30 to 300 MHz) |
| VIP | Very important person |
| VIS | Visibility |
| VLF | Very low frequency(3 to 30 kHz) |
| VLR | Very long range |
| VMC | Visual meteorological conditions |
| 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 |
| VTOL | Vertical take-off and landing |
| 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 |
| WAC | World Aeronautical Chart ICAO-1:1,000,000(followed by name/title) |
| WAFC | World area forecast center |
| WB | Westbound |
| WBAR | Wing bar lights |
| WDI | 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 |
| WIND | Wind |
| WINTEM | Forecast upper wind and temperature for aviation |
| 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 | World wide 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 message) |