Abbreviations not included in ICAO Doc. 8400 are marked with (*)
| 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 | |
| ABAS | * Aircraft Based Augmentation System |
| ABC | * Advance Booking Charter Flight |
| ABN | Aerodrome beacon |
| ACARS | (to be pronounced “AY-CARS”) Aircraft Communication addressing and Reporting System. |
| ACAS | Airborne collision avoidance system |
| ACC | Area control centre or area control |
| A-CDM | Airport Collaborative Decision Making |
| ACFT | Aircraft |
| ACK | Acknowledge |
| ACT | Active or activated or activity |
| AD | Aerodrome |
| ADC | Aerodrome chart |
| ADEP | * Airport of Departure |
| ADES | * Airport of Destination |
| ADEXP | * ATS Data Exchange Presentation |
| ADF | Automatic direction-finding equipment |
| ADIZ | (to be pronounced “AY-DIZ”) Air defence identification zone |
| ADS-B | Automatic dependent surveillance - broadcast |
| ADS-C | Automatic dependent surveillance - contract |
| AES | Aircraft earth station |
| AFIL | Flight plan filed in the air |
| AFIS | Aerodrome flight information service |
| AFN | * Air Traffic Services Facilities Notification |
| AFS | Aeronautical fixed service |
| AFTN | Aeronautical fixed telecommunication network |
| A/G | Air-to-ground |
| AGA | Aerodromes, air routes and ground aids |
| AGL | Above ground level |
| AIC | Aeronautical information circular |
| AIDC | Air traffic services inter-facility data communications |
| AIM | Aeronautical Information Management |
| AIP | Aeronautical information publication |
| AIRAC | Aeronautical information regulation and control |
| AIRMET | Information concerning en-route weather phenomena which may affect the safety of low-level aircraft operations |
| AIS | Aeronautical information services |
| ALRS | Alerting service |
| ALS | Approach lighting system |
| ALT | Altitude |
| ALTN | Alternate or alternating (light alternates in colour) |
| ALTN | Alternate (aerodrome) |
| ALTRV | * Altitude Reservation |
| AMA | Area minimum altitude |
| AMC | * Airspace Management Cell |
| AMC | * Acceptable Means of Compliance |
| AMDT | Amendment (AIP Amendment) |
| AMHS | * Aeronautical Message Handling System |
| AMO | * Aeronautical Meteorological Office |
| AMOS | * Aerodrome Meteorological Observing System |
| AMS | * Aeronautical Meteorological Station |
| AMSL | Above mean sea level |
| ANA | * Aeroportos de Portugal, SA |
| ANAC | * Autoridade Nacional da Aviação Civil (Portuguese CAA) |
| ANC | Aeronautical Chart 1:500 000 |
| ANM | * ATFM Notification Message |
| ANP | * Air Navigation Plan |
| AO | Aircraft Operator |
| AOC | Aerodrome obstacle chart (followed by type and name/title) |
| AOC | * Air operator certificate |
| APAPI | (to be pronounced “AY_PAPI”) Abbreviated precision approach path indicator |
| APCH | Approach |
| APDC | Aircraft parking/docking chart (followed by name title) |
| APIS | * Aircraft Parking and Information System |
| APP | Approach control office or approach control or approach control service |
| APR | April |
| APU | Auxiliary Power Unit |
| APV | Approach procedure with vertical guidance |
| ARC | Area chart |
| ARO | Air traffic services reporting office |
| ARP | Aerodrome reference point |
| ARP | Air-report (message type designator) |
| ARR | Arrival (message type designator) |
| ARR | Arrive or arrival |
| ART | * Article |
| AS | Altostratus |
| ASDA | Accelerate-stop distance available |
| ASE | Altimetry system error |
| ASHTAM | Special series of 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 |
| ASM | * Airspace Management |
| A-SMGCS | * Advanced Surface Movement Guidance and Control |
| ASMGL | * Aircraft Stand Manoeuvring Guidance Lights |
| ASPH | Asphalt |
| ATC | Air traffic control (in general) |
| ATCSMAC | Air traffic control surveillance minimum altitude chart |
| ATFCM | * Air Traffic Flow and Capacity Management |
| ATFM | Air traffic flow management |
| ATFMX | * ATFM Exempt Approved |
| ATIS | Automatic terminal information service |
| ATM | Air traffic management |
| ATM | * Automatic Teller Machine |
| ATN | Aeronautical telecommunication network |
| ATP | At... (time or place) |
| ATS | Air traffic services |
| ATZ | Aerodrome traffic zone |
| AUG | August |
| AUTO | Automatic |
| AVBL | Available or availability |
| A-VDGS | Advanced Visual Docking Guidance System |
| AVGAS | Aviation gasoline |
| 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 | |
| BAK | * Type of Arresting Gear |
| BARO-VNAV | Barometric vertical navigation (to be pronounced “BAA-RO - VEE-NAV “) |
| BDRY | Boundary |
| BFR | Before |
| BIRDTAM | * NOTAM Reporting Bird Hazard |
| BLW | Below |
| BP | * Breakaway point |
| BRG | Bearing |
| B-RNAV | * Basic Area Navigation |
| BTN | Between |
| BYD | * Beyond |
| 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 | Degrees Celsius (Centigrade) |
| C | * Charts |
| CA | Comando Aéreo |
| CAA | Civil Aviation Authority or Civil Aviation Administration |
| CAR | * Caribbean |
| CASA | * Computer Assisted Slot Allocation |
| CAT | Category |
| CBH | * Cloud Base Height |
| CDA | * DCL Clearance Echoback |
| CDO | Continuous Descent Operations |
| CDR | Conditional Route |
| CF | Course to a fix |
| CFMU | * Central Flow Management Unit |
| CH | Channel |
| CHCK | * Chocks |
| CHG | Modification (message type designator) |
| CIDIN | Common ICAO data interchange network |
| - 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 - 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 | |
| CL | Centre line |
| CLBR | Calibration |
| CLD | Cloud |
| CLD | * Departure clearance uplink message |
| CLR | Clear(s) or cleared to... or clearance |
| CM | Centimetre |
| CMA | * Centro de Meteorologia Aeronáutica |
| CNL | Flight plan cancellation (message type designator) |
| CODE | * ICAO Aircraft Address in alphanumerical of six hexadecimal characters format |
| COM | Communications |
| CONC | Concrete |
| CONS | Continuous |
| COORD | Coordinates |
| COP | Change-over point |
| CPDLC | Controller-pilot data link communications |
| CPL | Current flight plan (message type designator) |
| CPVM-AERO | * Centro de Previsão e Vigilância Meteorológica para a aeronáutica |
| CR | * Cross Sections |
| CR | * Change Request |
| CRC | Cyclic redundancy check |
| CRC | * Control and Reporting Centre |
| CRZ | Cruise |
| CS | Call sign |
| CSF | * Communication Support Facility |
| CTA | Control area |
| CTC | Contact |
| CTL | Control |
| CTOT | * Calculated Take-off Time |
| CTR | Control zone |
| CVR | Cockpit voice recorder |
| CWY | Clearway |
| D - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z GLOSSARY OF TERMS | |
| D... | Danger area (followed by identification) |
| DA | Decision altitude |
| DAT | * Data link |
| DCL | * Data link departure clearance |
| DCT | Direct (in relation to flight plan clearances and type of approach) |
| DCPC | Direct controller-pilot communications |
| DEC | December |
| DEG | Degrees |
| DEP | Depart or departure |
| DEP | Departure (message type designator) |
| DES | * De-suspension Message |
| DEST | Destination |
| DF | Direction finding |
| DIST | Distance |
| DLA | Delay or delayed |
| DLA | Delay (message type designator) |
| DLE | * En-route delay or holding |
| DLIC | Data link initiation capability |
| DLM | * Data link mandate |
| DME | Distance measuring equipment |
| DNM | * Directorate Network Management (EUROCONTROL) |
| DOC | * Document |
| DOF | Date of Flight (YYMMDD) |
| DTG | Date-time group |
| DVOR | Doppler VOR |
| DVORTAC | * DVOR and TACAN Combination |
| 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 |
| EAD | * European AIS Database |
| EASA | * European Aviation Safety Agency |
| EAT | Expected approach time |
| EC | * European Community |
| ECAC | * European Civil Aviation Conference |
| EET | Estimated elapsed time |
| EGNOS | European Geostationary Navigation Overlay System |
| EGPWS | * Enhanced Ground Proximity Warning System |
| ELBA | Emergency location beacon - aircraft |
| ELEV | Elevation |
| ELR | Extra long range |
| ELT | Emergency locator transmitter |
| EN | * English |
| END | Stop-end (related to RVR) |
| ENR | En route |
| ENRC | Enroute Chart |
| EOBT | Estimated off-block time |
| EPNdB | * Effective perceived noise in decibels |
| EQPT | Equipment |
| ERR | * Error Message |
| ESE | East-south-east |
| EST | Estimate or estimated or estimate (message type designator) |
| ETA | Estimated time of arrival or estimating arrival |
| ETD | Estimated time of departure or estimating departure |
| ETFMS | * Enhanced Tactical Flow Management System |
| ETO | Estimated time over significant point |
| ETOT | * Estimated Take-off Time |
| EU | * European Union |
| EUR | * European Region |
| EUROCONTROL | * European Organisation for the Safety of Air Navigation |
| EV | Every |
| 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 | |
| FA | Course from a fix to an altitude |
| FAA | * Federal Aviation Agency |
| FAF | Final approach fix |
| FAL | Facilitation of international air transport |
| FAM | * Flight Activation Monitoring |
| FANS | * Future Air Navigation Systems |
| FAP | Final approach point |
| FAP | * Força Aérea Portuguesa (Portuguese Air Force) |
| FAS | Final approach segment |
| FATO | Final approach and take-off area |
| FAX | Facsimile transmission |
| FCST | Forecast |
| FCT | Friction coefficient |
| FEB | February |
| FFR | * Fire Fighting |
| FFS | * Fire Fighting Service |
| FIC | Flight information centre |
| FIR | Flight information region |
| FIS | Flight information service |
| FL | Flight level |
| FLG | Flashing |
| FLS | * Flight Suspension Message |
| FLTCK | Flight check |
| FLW | Follow(s) or following |
| FM | * Modulated Frequency |
| FM | From |
| FMC | Flight management computer |
| FMD | * Former CFMU Flow Management Division |
| FMP | * Flow Management Position |
| FMS | Flight management system |
| FNA | Final approach |
| FPL | Flight plan |
| FOSA | * Flight Operations Safety Assessment |
| FRA | * Free Route Airspace |
| FREQ | Frequency |
| FRI | Friday |
| FROP | * Final Approach Roll-Out Point |
| FSM | * Flight system update link message |
| FSTD | * Flight Simulation Training Device |
| FT | Feet (dimensional unit) |
| 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 |
| GA | Go ahead, resume sending (to be used in AFS as a procedure signal) |
| GA | General aviation |
| - 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 - 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 | |
| GAMET | Area forecast for low-level flights |
| GAT | * General Air Traffic |
| GEN | General |
| GEO | Geographic or true |
| GH | * Ground Handling |
| GIMFA | * Grupo de Informação Meteorológica da Força Aérea (Air Force MET Information Group) |
| GMC | Ground movement chart (followed by name/title) |
| GND | Ground |
| GNSS | Global navigation satellite system |
| GP | Glide path |
| GPA | Glide path angle |
| GPIAAF | * Gabinete de Prevenção e Investigação de Acidentes com Aeronaves e de Acidentes Ferroviários |
| GPS | Global positioning system |
| GPU | Ground Power Unit |
| GPWS | Ground Proximity Warning System |
| GR | Hail |
| GRF | * Global reporting format |
| GRASS | Grass landing area |
| GS | Small hail and/or snow pellets |
| GS | Ground Speed |
| 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 | * Hour |
| H24 | Continuous day and night service |
| HAZMAT | * Hazardous Material |
| HEL | * Helicopter or Heliport |
| HEMS | * Hospital Emergency Medical Service |
| HF | High frequency [3 000 to 30 000 kHz] |
| HGT | Height or height above |
| HJ | Sunrise to sunset |
| HLA | High Level Airspace |
| HLDG | Holding |
| HM | Holding/racetrack to a manual termination |
| HN | Sunset to sunrise |
| HO | Service available to meet operational requirements |
| HOL | Holiday |
| HOSP | Hospital aircraft |
| HPA | Hectopascal |
| HR | Hours |
| HS | Service available during hours of scheduled operations |
| HUM | Humanitarian |
| HX | No specific working hours |
| 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 |
| IAP | Instrument Approach Procedure |
| IAS | Indicated airspeed |
| IATA | * International Air Transport Association |
| IBN | Identification beacon |
| ICAO | International Civil Aviation Organization |
| ID | Identifier or identify |
| IDENT | Identification |
| IF | Intermediate approach fix |
| IFPS | * Integrated Initial Flight Plan Processing System |
| IFPU | * Integrated Initial Flight Plan Processing Unit |
| IFPZ | * IFPS Zone |
| IFR | Instrument flight rules |
| ILS | Instrument landing system |
| IM | Inner marker |
| IMC | Instrument meteorological conditions |
| INA | Initial approach |
| INBD | Inbound |
| INFO | Information |
| INOP | Inoperative |
| INS | Inertial navigation system |
| INT | Intersection |
| INTL | International |
| INTST | Intensity |
| IPMA | * Instituto Português do Mar e da Atmosfera |
| IRS | Inertial reference system |
| IRU | * Inertial reference unit |
| ITC | * Inclusive Tour Charter Flight |
| 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 |
| 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 |
| KT | Knots |
| 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 identification) |
| L | Locator (see LM, LO) |
| LAT | Latitude |
| LCN | * Load Classification Number |
| LDA | Landing distance available |
| LDG | Landing |
| LDI | Landing direction indicator |
| 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 | Lateral navigation (to be pronounced “EL-NAV”) |
| LO | Locator, outer |
| LoA | * Letter of agreement |
| LOC | Localizer |
| LONG | Longitude |
| LORAN | LORAN (long range air navigation system) |
| LP | * Localizer Performance |
| LPV | Localizer performance with vertical guidance |
| LRG | Long range |
| LVL | Level |
| LVP | Low Visibility Procedures |
| LVO | * Low Visibility Operation |
| 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 | Mach number (followed by figures) |
| M | Metres (preceded by figures) |
| MAG | Magnetic |
| MAP | Aeronautical maps and charts |
| MAPT | Missed approach point |
| MAR | March |
| MARSA | * Military Assumes Responsibility for Separation of Aircraft |
| MATF | Missed approach turning fix |
| MAX | Maximum |
| MAY | May |
| MCTA | * Military Control Area |
| MCTR | Military Control Zone |
| MCW | Modulated continuous wave |
| MDA | Mínimum descent altitude |
| MEA | Mínimum enroute altitude |
| MEDEVAC | Medical Evacuation Flight |
| MEHT | Minimum, eye height over threshold (for visual approach slope indicator systems) |
| MEL | Minimum Equipment List |
| MET | Meteorological or meteorology |
| METAR | Aviation routine weather report (in aeronautical meteorological code) |
| MF | Medium frequency (300 to 3 000 khz) |
| MHA | Minimum Holding Altitude |
| MHZ | Megahertz |
| MID | Mid-point (related to RVR) |
| MIL | Military |
| MIN | Minutes |
| MLAT | * Multilateration |
| MLS | Microwave landing system |
| MM | Middle marker |
| MNM | Minimum |
| MNPS | Minimum navigation performance specifications |
| MNPSA | Minimum navigation performance specifications airspace |
| MON | Monday |
| MS | Minus |
| MSA | Minimum sector altitude |
| MSAW | Minimum Safe Altitude Warning |
| MSL | Mean sea level |
| MSSR | Monopulse secondary surveillance radar |
| MTOM | Maximum take-off mass |
| MTOW | * Maximum take-off weight |
| MWO | Meteorological watch office |
| 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 | North or northern latitude |
| N/A | * Not Applicable |
| NAC | * Navigation accuracy category |
| NAT | North Atlantic |
| NATSPG | * North Atlantic Systems Planning Group |
| NAV | Navigation |
| NAVAID | Navigation Aid |
| NDB | Non-directional radio beacon |
| NE | North-east |
| NIC | * Navigation integrity category |
| NIL | None or I have nothing to send to you |
| NM | Nautical miles |
| NNW | North-north-west |
| NOC | * National OPMET Centre |
| NOF | International NOTAM office |
| 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 |
| NPA | Non-precision approach |
| NR | Number |
| NS | * Non-schedule |
| NTL | National |
| NUCp | * Navigation Uncertainty Category for Position |
| NVO | * Normal Visibility Operations |
| NW | North-west |
| 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 |
| OBST | Obstacle |
| OCA | Obstacle clearance altitude |
| OCA | Oceanic control area |
| OCD | * Oceanic Clearance Delivery |
| OCH | Obstacle Clearance Height |
| OCL | * Obstacle Clearance Limit |
| OCL | * Oceanic Clearance |
| OCT | October |
| OFZ | Obstacle free zone |
| OK | We agree or it is correct (to be used in AFS as a procedure signal) |
| OLDI | On-line data interchange |
| OM | Outer marker |
| OPMET | Operational meteorological (information) |
| OPR | Operator or operate or operative or operating or operational |
| OPS | Operations |
| ORGN | * Originator of the flight plan |
| OTR | * Other |
| OTS | Organized track system |
| OUBD | Outbound |
| OWAFS | * Operations without assigned fixed speed |
| 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 | * Personal Consultation |
| P | * Prognostic Upper Air Chart |
| P | * Private |
| P | * Provided |
| PALS | Precision approach lighting system (specify category) |
| PANS | Procedures for air navigation services |
| PAPI | Precision approach path indicator |
| PAR | Precision approach radar |
| PATC | Precision approach terrain chart (followed by name/title) |
| PAX | Passenger(s) |
| PBN | Performance-based navigation |
| PCN | Pavement classification number |
| PDG | Procedure design gradient |
| PER | Performance |
| PERM | Permanent |
| PIB | Pre-flight information bulletin |
| PL | *Abbreviated Plain Language Texts |
| PN | Prior notice required |
| POB | Persons on board |
| POS | * Position Report |
| PPR | Prior permission required |
| PS | Plus |
| PSP | Polícia de Segurança Pública |
| PT | * Portuguese |
| PTN | Procedure turn |
| PWR | Power |
| Q - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z GLOSSARY OF TERMS | |
| QDM | Magnetic Heading (zero wind) |
| QDR | Magnetic bearing |
| QFE | Atmospheric pressure at aerodrome elevation (or at runway threshold) |
| QNH | Altimeter sub-scale setting to obtain elevation when on the ground |
| 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 designation number to identify a parallel runway) |
| R | Red |
| R | Received (acknowledgement of receipt) (to be used in AFS as a procedure signal) |
| R... | Restricted area (followed by identification) |
| R... | Runway followed by figures in METAR/SPECI |
| R... | Radial (from VOR followed by three figures) |
| RAC | Rules of the air and air traffic services |
| RAD | * Route Availability Document |
| RADAR | * Radio Detection and Ranging |
| RAG | Runway arresting gear |
| RALT | * Route Alternative |
| RAIM | Receiver autonomous integrity monitoring |
| RCC | Rescue coordination centre |
| RCD | * Request for enroute clearance downlink |
| RCF | Radio communication failure (message type designator) |
| RCR | * Runway condition report |
| RCLL | Runway centre line light(s) |
| RCP | Required communication performance |
| RDH | Reference Datum Height (for ILS) |
| RDL | Radial |
| RDO | Radio |
| REA | * Ready Message |
| REG | Registration |
| REP | Report or reporting or reporting point |
| REQ | Request or requested |
| RESA | Runway end safety area |
| RET | * Rapid Exit Taxiway |
| RETIL | * Rapid Exit Taxiway Indicator Lights |
| RF | Constant radius arc to a fix |
| RFF | * Rescue and Fire Fighting |
| RFFS | Rescue and Fire Fighting Services |
| RFP | * Replacement Flight Plan (related to ATFM) |
| RIB | * Rigid Inflatable Boat |
| RIF | Reclearance in flight |
| RMK | Remark |
| RNAV | (to be pronounced “AR-NAV”) Area navigation |
| RNP | Required Navigation Performance |
| RNP-AR | * Required Navigation Performance - Authorization Required |
| ROC | Rate of climb |
| RP | * Recommended Practice |
| RRP | Rerouting Proposal Message |
| RSC | Rescue sub-centre |
| RTE | Route |
| RTF | Radiotelephone |
| RTIL | * Runway Threshold Identification Lights |
| RVR | Runway visual range |
| RVSM | Reduced Vertical Separation Minimum |
| 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 | * Seconds |
| S | South or southern latitude |
| S | * Surface Analysis (Current Chart) |
| S | * Schedule |
| SALS | Simple approach lighting system |
| SAM | * Slot Allocation Message |
| SAR | Search and rescue |
| SAT | Saturday |
| SATCOM | Satellite communication (used only when referring generally to both voice and data satellite communication or only data satellite communication) |
| SATEL | * Satellite Image |
| SATVOICE | Satellite Voice communication |
| SB | Southbound |
| SBA | * Aerodrome brigade service |
| SBAS | Space Based Augmentation System |
| SBSLCI | * Basic service of rescue and firefighting |
| SDF | Step Down fix |
| SE | South-east |
| SEC | Seconds |
| SEL | * Selcal Code |
| SELCAL | Selective calling system |
| SEP | September |
| SERA | * Standardised European Rules of the Air |
| SFC | Surface |
| SID | Standard instrument departure |
| SIGMET | Information concerning en-route weather and other phenomena in the atmosphere that may affect the safety of aircraft operations |
| SIGWX | * Significant weather |
| SIL | * Surveillance integrity level |
| SMA | * Schedule Movement Advice |
| SIP | * Slot Improvement Proposal Message |
| SITA | * Société Internationale des Telecommunications Aeronautiques |
| SIWL | Single isolated wheel load |
| SLC | * Slot Cancellation Message |
| SMC | Surface movement control |
| SMR | Surface movement radar |
| 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 |
| SOP | * Standard operating procedure |
| SPA | * Slot Improvement Proposal Acceptance Message |
| SPECI | Aviation selected special weather report (in aeronautical meteorological code) |
| SPECIAL | Special meteorological report (in abbreviated plain language) |
| SR | Sunrise |
| SRA | Surveillance radar approach |
| SRJ | * Slot Improvement Proposal Rejection Message |
| SRM | * Slot Revision Message |
| SRR | Search and rescue region |
| SS | Sunset |
| SSE | South-south-east |
| SSR | Secondary surveillance radar |
| SST | Supersonic transport |
| SSW | South-south-west |
| STAR | Standard instrument arrival |
| STS | Status |
| SUN | Sunday |
| SUP | Supplement (AIP Supplement) |
| SUPPS | Regional supplementary procedures |
| SUR | * Surveillance Equipment |
| SVC | Service (message type only) |
| SW | South-west |
| SWH | * Significant Weather High Chart |
| SWM | * Significant Weather Medium Chart |
| SWM | * Sip Wanted Message |
| SWY | Stopway |
| SYNOP | * Surface Synoptic Observations |
| 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 | True (preceded by a bearing to indicate reference to True North) |
| T | * Telephone |
| T-VASIS | T-Visual Approach Slope Indicator System |
| TAA | Terminal arrival Altitude |
| TACAN | UHF tactical air navigation aid |
| TACT | * CFMU Tactical |
| TAF | Aerodrome forecast |
| TALT | * Take-off alternate aerodrome(s) |
| TAS | True airspeed |
| TAWS | * Terrain Awareness and Warning System |
| TBN | * To Be Notified |
| TCAS | * Traffic alert and collision avoidance system |
| TCH | Threshold crossing height |
| TCP | * Transfer Control Point |
| TDZ | Touchdown zone |
| TEL | Telephone |
| TERPS | * Terminal Procedures |
| TF | Track to fix |
| TFC | Traffic |
| TGL | Touch-and-go landing |
| TGS | Taxiing guidance system |
| THR | Threshold |
| THRU | Through |
| THU | Thursday |
| TIL | Until |
| TKOF | Take-off |
| TLOF | Touchdown and lift-off area |
| TMA | Terminal control area |
| TOBT | * Target Off-Block Time |
| TODA | Take-off distance available |
| TOGA | * Take-off Go Around |
| TORA | Take-off run available |
| TR | Track |
| TRA | Temporary reserved airspace |
| TRMZ | * Transponder Radio Mandatory Zone |
| TSAT | * Target Start-Up Approval Time |
| TUE | Tuesday |
| TWR | Aerodrome control tower or aerodrome control |
| TWY | Taxiway |
| TYP | Type of aircraft |
| 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 | |
| UFN | Until further notice |
| UHF | Ultra high frequency [300 to 3 000 MHz] |
| UIR | Upper flight information region |
| ULM | Ultra Light motorized Aircraft |
| UNHCR | * United Nations High Commissioner for Refugees |
| UNL | Unlimited |
| UPR | * User-preferred route |
| UTC | Coordinated 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 GLOSSARY OF TERMS | |
| VAC | Visual approach chart (followed by name/title) |
| VALC | * Visual Approach and Landing Chart |
| VAR | * Magnetic variation |
| VASIS | Visual approach slope indicator systems |
| VET | * Veterinary |
| VFR | Visual flight rules |
| VHF | Very high frequency (30 to 300 MHz) |
| VIS | Visibility |
| VLR | Very long range |
| VM | Heading to a manual termination |
| VMC | Visual meteorological conditions |
| VNAV | Vertical navigation (to be pronounced VEE_NAV) |
| VOLMET | Meteorological information for aircraft in flight |
| VOR | VHF omnidirectional radio range |
| VORTAC | VOR and TACAN combination |
| VRB | Variable |
| VSS | * Visual segment surface |
| VTOF | * Visual Take-off |
| 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 | * Significant Weather Chart |
| WRNG | Warning |
| WBAR | Wing bar lights |
| WDI | Wind direction indicator |
| WED | Wednesday |
| WGS-84 | World Geodetic System - 1984 |
| WID | Width or wide |
| WILCO | Will comply |
| WIP | Work in progress |
| WNW | West-North-West |
| WPT | Way-point |
| WT | Weight |
| WWW | Worldwide web |
| WX | Weather |
| WXR | Weather Radar |
| 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 |
| YES | Yes (affirmative) (to be used in AFS as a procedure signal) |