Aviation acronyms
What does it stand for?
Hundreds of acronyms run right through the PPL ground studies, and they appear in the exams too. We've gathered virtually every one: meteorological codes in METARs and TAFs, general aviation abbreviations, and those used in aeronautical messages.
1025 acronyms, A to Z
A
- AAmber
- AAAir to Air
- AAAAmended meteorological message (message type designator). (or AAB, AAC . . . etc., in sequence).
- AADAssigned altitude deviation
- AAIMAircraft Autonomous Integrity Monitoring
- AALAbove Aerodrome Level
- ABIAdvance Boundary Information
- ABMAbeam
- ABNAerodrome Beacon
- ABTAbout
- ABVAbove
- ACAltocumulus
- ACARSAircraft Communication Addressing and Reporting System. (to be pronounced “AY-CARS”)
- ACASAirborne Collision Avoidance System
- ACCArea Control Centre or Area Control
- ACCIDACCIDENT (Notification of an aircraft accident)
- ACFTAIRCRAFT
- ACKACKNOWLEDGE
- ACLAltimeter Check Location
- ACNAircraft Classification Number
- ACPACCEPTANCE (message type designator)
- ACPTACCEPT or ACCEPTED
- ACTACTIVE or ACTIVATED or ACTIVITY
- ADAERODROME
- ADAADVISORY AREA
- ADCAERODROME CHART
- ADDNADDITION or ADDITIONAL
- ADFAutomatic Direction-Finding Equipment
- ADIZAir Defence Identification Zone (to be pronounced “AY-DIZ”)
- ADJAdjacent
- ADOAerodrome Office (specify service)
- ADRAdvisory Route
- ADSThe Address - (when this abbreviation is used to request a repetition, the question mark (IMI) precedes the abbreviation, e.g. IMI ADS) (to be used in AFS as a procedure signal). Signal is also available for use in communicating with stations of the maritime mobile service
- ADSBAutomatic dependent surveillance broadcast
- ADSCAutomatic Dependent Surveillance Contract
- ADSUAutomatic dependent surveillance unit
- ADVSAdvisory service
- ADZAdvise
- AESAircraft earth station
- AFILFlight plan filed in the air
- AFISAerodrome flight information service
- AFMYes or affirm or affirmative or that is correct
- AFSAeronautical fixed service
- AFTAfter . . . (time or place)
- AFTNAeronautical fixed telecommunication network
- AGAir-to-ground
- AGAAerodromes, air routes and ground aids
- AGLAbove ground level
- AGNAgain
- AICAeronautical information circular
- AIDCAir traffic services interfacility data communications
- AIPAeronautical information publication
- AIRACAeronautical information regulation and control
- AIREPAir-report
- AIRMETInformation concerning en-route weather phenomena which may affect the safety of low-level aircraft operations
- AISAeronautical information services
- ALAAlighting area
- ALERFAAlert phase
- ALRAlerting (message type designator)
- ALRSAlerting service
- ALSApproach lighting system
- ALTAltitude
- ALTNAlternate or alternating (light alternates in colour); Alternate (aerodrome)
- AMAArea minimum altitude
- AMDAmend or amended (used to indicate amended meteorological message; message type designator)
- AMDTAmendment (AIP Amendment)
- AMSAeronautical mobile service
- AMSLAbove mean sea level
- AMSSAeronautical mobile satellite service
- ANCAeronautical chart
- ANCSAeronautical navigation chart
- ANSAnswer
- AOCAerodrome obstacle chart (followed by type and name/title)
- APAirport
- APAPIAbbreviated Precision Approach Path Indicator
- APCHApproach
- APDCAircraft parking/docking chart (followed by name/title)
- APNApron
- APPApproach control office or approach control or approach control service
- APRApril
- APRXApproximate or approximately
- APSGAfter passing
- APVApprove or approved or approval
- ARCArea chart
- ARNGArrange
- AROAir traffic services reporting office
- ARPAerodrome reference point; Air-report (message type designator)
- ARQAutomatic error correction
- ARRArrival (message type designator); Arrive or arrival
- ARSSpecial air-report (message type designator)
- ARSTArresting (specify (part of) aircraft arresting equipment)
- ASAltostratus
- ASCAscend to or ascending to
- ASDAAccelerate-stop distance available
- ASEAltimetry system error
- ASHTAMSpecial series NOTAM notifying, by means of a specific format, change in activity of a volcano, a volcanic eruption and/or volcanic ash cloud that is of significance to aircraft operations
- ASPHAsphalt
- ATAt (followed by time at which weather change is forecast to occur)
- ATAActual time of arrival
- ATCAir traffic control (in general)
- ATCSMACAir traffic control surveillance minimum altitude chart (followed by name/title)
- ATDActual time of departure
- ATFMAir traffic flow management
- ATISAutomatic terminal information service
- ATMAir traffic management
- ATNAeronautical telecommunication network
- ATPAt . . . (time or place)
- ATSAir traffic services
- ATTNAttention
- ATVASISAbbreviated T Visual Approach Slope Indicator System
- ATZAerodrome traffic zone
- AUGAugust
- AUTHAuthorized or authorization
- AUWAll up weight
- AUXAuxiliary
- AVBLAvailable or availability
- AVGAverage
- AVGASAviation gasoline
- AWTAAdvise at what time able
- AWYAirway
- AZMAzimuth
B
- BBlue
- BABraking action
- BAROVNAVBarometric Vertical Navigation
- BASECloud base
- BCFGFog patches
- BCNBeacon (aeronautical ground light)
- BCSTBroadcast
- BDRYBoundary
- BECMGBecoming
- BFRBefore
- BKNBroken
- BLBlowing (followed by DU = dust, SA = sand or SN = snow)
- BLDGBuilding
- BLOBelow clouds
- BLWBelow . . .
- BOMBBombing
- BRMist
- BRFShort (used to indicate the type of approach desired or required)
- BRGBearing
- BRKGBraking
- BSCommercial broadcasting station
- BTLBetween layers
- BTNBetween
- BUFRBinary universal form for the representation of meteorological data
C
- CDegrees Celsius (Centigrade)
- CACourse to an altitude
- CATCategory; Clear air turbulence
- CAVOKCeiling and Visibility OK
- CBCumulonimbus
- CCCirrocumulus
- CCACorrected meteorological message (or CCB, CCC . . . etc., in sequence)
- CDCandela
- CDNCoordination (message type designator)
- CFChange frequency to . . .; Course to a fix
- CFMConfirm or I confirm (to be used in AFS as a procedure signal)
- CGLCircling guidance light(s)
- CHChannel; This is a channel-continuity-check of transmission to permit comparison of your record of channelsequence numbers of messages received on the channel (to be used in AFS as a procedure signal)
- CHEMChemical
- CHGModification (message type designator)
- CICirrus
- CIDINCommon ICAO data interchange network
- CITNear or over large towns
- CIVCivil
- CKCheck
- CLCentre line
- CLAClear type of ice formation
- CLBRCalibration
- CLDCloud
- CLGCalling
- CLIMB-OUTClimb-out area
- CLRClear(s) or cleared to . . . or clearance
- CLRDRunway(s) cleared (used in METAR/SPECI)
- CLSDClose or closed or closing
- CMCentimetre
- CMBClimb to or climbing to
- CMPLCompletion or completed or complete
- CNLCancel or cancelled; Flight plan cancellation (message type designator)
- CNSCommunications, navigation and surveillance
- COMCommunications
- CONCConcrete
- CONDCondition
- CONSContinuous
- CONSTConstruction or constructed
- CONTContinue(s) or continued
- COORCoordinate or coordination
- COORDCoordinates
- COPChange-over point
- CORCorrect or correction or corrected (used to indicate corrected meteorological message; message type designator)
- COTAt the coast
- COVCover or covered or covering
- CPDLCController-pilot data link communications
- CPLCurrent flight plan (message type designator)
- CRCCyclic redundancy check
- CRMCollision risk model
- CRZCruise
- CSCall sign; Cirrostratus
- CTAControl area
- CTAMClimb to and maintain
- CTCContact
- CTLControl
- CTNCaution
- CTRControl zone
- CUCumulus
- CUFCumuliform
- CUSTCustoms
- CVRCockpit voice recorder
- CWContinuous wave
- CWYClearway
D
- DDanger area (followed by identification)
- D-ATISData Link Automatic Terminal Information Service
- DADecision altitude
- DCDDouble channel duplex
- DCKGDocking
- DCPDatum crossing point
- DCPCDirect controller-pilot communications
- DCSDouble channel simplex
- DCTDirect (in relation to flight plan clearances and type of approach)
- DEFrom (used to precede the call sign of the calling station) (to be used in AFS as a procedure signal)
- DECDecember
- DEGDegrees
- DEPDepart or departure; Departure (message type designator)
- DEPODeposition
- DERDeparture end of the runway
- DESDescend to or descending to
- DESTDestination
- DETRESFADistress phase
- DEVDeviation or deviating
- DFDirection finding
- DFDRDigital flight data recorder
- DFTIDistance from touchdown indicator
- DHDecision height
- DIFDiffuse
- DISTDistance
- DIVDivert or diverting
- DLADelay or delayed; Delay (message type designator)
- DLICData link initiation capability
- DLYDaily
- DMEDistance measuring equipment
- DNGDanger or dangerous
- DODownward (tendency in RVR during previous 10 minutes)
- DOMDomestic
- DPDew point temperature
- DPTDepth
- DRLow drifting (followed by DU = dust, SA = sand or SN = snow)
- DREDead reckoning
- DRGDuring
- DSDuststorm
- DSBDouble sideband
- DTAMDescend to and maintain
- DTGDate-time group
- DTHRDisplaced runway threshold
- DTRTDeteriorate or deteriorating
- DTWDual tandem wheels
- DUDust
- DUCDense upper cloud
- DUPEThis is a duplicate message (to be used in AFS as a procedure signal)
- DURDuration
- DVOLMETData link VOLMET
- DVORDoppler VOR
- DWDual wheels
- DZDrizzle
E
- EEast or eastern longitude
- EATExpected approach time
- EBEastbound
- EDAElevation differential area
- EEEError (to be used in AFS as a procedure signal)
- EETEstimated elapsed time
- EFCExpect further clearance
- EFISElectronic Flight Instrument System
- EGNOSEuropean Geostationary Navigation System
- EHFExtremely high frequency [30 000 to 300 000 MHz]
- ELBAEmergency location beacon
- ELEVElevation
- ELRExtra long range
- ELTEmergency locator transmitter
- EMEmission
- EMBDEmbedded in a layer (to indicate cumulonimbus embedded in layers of other clouds)
- EMERGEmergency
- ENDStop-end (related to RVR)
- ENEEast-north-east
- ENGEngine
- ENREn route
- ENRCEnroute chart (followed by name/title)
- EOBTEstimated off-block time
- EQPTEquipment
- ERHere . . . or herewith
- ESEEast-south-east
- ESTEstimate or estimated or estimation (message type designator)
- ETAEstimated time of arrival or estimating arrival
- ETDEstimated time of departure or estimating departure
- ETOEstimated time over significant point
- EURRODEXEuropean regional OPMET data exchange
- EVEvery
- EVSEnhanced vision system
- EXCExcept
- EXERExercises or exercising or to exercise
- EXPExpect or expected or expecting
- EXTDExtend or extending
F
- FFixed
- FACourse from a fix to an altitude
- FACFacilities
- FAFFinal approach fix
- FALFacilitation of international air transport
- FAPFinal approach point
- FASFinal approach segment
- FATOFinal approach and take-off area
- FAXFacsimile transmission
- FBLLight (used to indicate the intensity of
- FCFunnel cloud (tornado or water spout)
- FCSTForecast
- FCTFriction coefficient
- FDPSFlight data processing system
- FEBFebruary
- FEWFew
- FGFog
- FICFlight information centre
- FIRFlight information region
- FISFlight information service
- FISAAutomated flight information service
- FLFlight level
- FLDField
- FLGFlashing
- FLRFlares
- FLTFlight
- FLTCKFlight check
- FLUCFluctuating or fluctuation or fluctuated
- FLWFollow(s) or following
- FLYFly or flying
- FMFrom
- FMCFlight management computer
- FMSFlight management system
- FMUFlow management unit
- FNAFinal approach
- FPAPFlight path alignment point
- FPLFiled flight plan (message type designator)
- FPMFeet per minute
- FPRFlight plan route
- FRFuel remaining
- FREQFrequency
- FRIFriday
- FRNGFiring
- FRONTFront (relating to weather)
- FROSTFrost (used in aerodrome warnings)
- FRQFrequent
- FSLFull stop landing
- FSSFlight service station
- FSTFirst
- FTFeet (dimensional unit)
- FTEFlight technical error
- FTPFictitious threshold point
- FTTFlight technical tolerance
- FUSmoke
- FZFreezing
- FZDZFreezing drizzle
- FZFGFreezing fog
- FZRAFreezing rain
G
- GVariations from the mean wind speed (gusts) (followed by figures in METAR/SPECI and TAF)
- GAGo ahead, resume sending (to be used in AFS as a procedure signal)
- GAGGround-to-air and air-to-ground
- GAGANGPS and geostationary earth orbit augmented navigation
- GAINAirspeed or headwind gain
- GAMETArea forecast for low-level flights
- GARPGBAS azimuth reference point
- GBASGround Based Augmentation System
- GCAGround controlled approach system or ground controlled approach
- GENGeneral
- GEOGeographic or true
- GESGround earth station
- GLDGlider
- GLONASSGlobal Orbiting Navigation Satellite System
- GLSGBAS landing system
- GMCGround movement chart (followed by name/title)
- GNDGround
- GNDCKGround check
- GNSSGlobal navigation satellite system
- GPGlide path
- GPAGlide path angle
- GPIPGlide path intercept point
- GPSGlobal positioning system
- GPWSGround proximity warning system
- GRHail
- GRASGround Based Regional Augmentation System
- GRASSGrass landing area
- GRIBProcessed meteorological data in the form of grid point values expressed in binary form (meteorological code)
- GRVLGravel
- GSSmall hail and/or snow pellets
- GUNDGeoid undulation
H
- HHigh pressure area or the centre of high pressure
- H24Continuous day and night service
- HAHolding/racetrack to an altitude
- HAPIHelicopter approach path indicator
- HBNHazard beacon
- HDFHigh frequency direction-finding station
- HDGHeading
- HELHelicopter
- HFHigh frequency [3 000 to 30 000 kHz]
- HGTHeight or height above
- HJSunrise to sunset
- HLDGHolding
- HMHolding/racetrack to a manual termination
- HNSunset to sunrise
- HOService available to meet operational requirements
- HOLHoliday
- HOSPHospital aircraft
- HPAHectopascal
- HRHours
- HSService available during hours of scheduled operations
- HUDHead-up display
- HURCNHurricane
- HVDFHigh and very high frequency direction- finding stations (at the same location)
- HVYHeavy; Heavy (used to indicate the intensity of weather phenomena, e.g. HVY RA = heavy rain)
- HXNo specific working hours
- HYRHigher
- HZHaze; Hertz (cycle per second)
I
- IACInstrument approach chart (followed by name/title)
- IAFInitial approach fix
- IAOIn and out of clouds
- IAPInstrument approach procedure
- IARIntersection of air routes
- IASIndicated airspeed
- IBNIdentification beacon
- ICIce crystals (very small ice crystals in suspension, also known as diamond dust)
- ICEIcing
- IDIdentifier or identify
- IDENTIdentification
- IFIntermediate approach fix
- IFFIdentification friend/foe
- IFRInstrument flight rules
- IGAInternational general aviation
- ILSInstrument landing system
- IMInner marker
- IMCInstrument meteorological conditions
- IMGImmigration
- IMIInterrogation sign (question mark) (to be used in AFS as a procedure signal)
- IMPRImprove or improving
- IMTImmediate or immediately
- INAInitial approach
- INBDInbound
- INCIn cloud
- INCERFAUncertainty phase
- INFOInformation
- INOPInoperative
- INPIf not possible
- INPRIn progress
- INSInertial navigation system
- INSTLInstall or installed or installation
- INSTRInstrument
- INTIntersection
- INTLInternational
- INTRGInterrogator
- INTRPInterrupt or interruption or interrupted
- INTSFIntensify or intensifying
- INTSTIntensity
- IRIce on runway
- IRSInertial reference system
- ISAInternational standard atmosphere
- ISBIndependent sideband
- ISOLIsolated
J
K
L
- LLeft (preceded by runway designation number to identify a parallel runway)
- LAMLogical acknowledgement (message type designator)
- LANInland
- LATLatitude
- LCALocal or locally or location or located
- LDALanding distance available
- LDAHLanding distance available, helicopter
- LDGLanding
- LDILanding direction indicator
- LENLength
- LFLow frequency [30 to 300 kHz]
- LGTLight or lighting
- LGTDLighted
- LIHLight intensity high
- LILLight intensity low
- LIMLight intensity medium
- LINELine (used in SIGMET)
- LMLocator, middle
- LMTLocal mean time
- LNAVLateral Navigation
- LNGLong (used to indicate the type of approach desired or required)
- LOLocator, outer
- LOCLocalizer
- LONGLongitude
- LORANLORAN (long range air navigation system)
- LOSSAirspeed or headwind loss
- LPVLocalizer performance with vertical guidance
- LRThe last message received by me was . . . (to be used in AFS as a procedure signal)
- LRGLong range
- LSThe last message sent by me was . . . or Last message was . . . (to be used in AFS as a procedure signal)
- LTDLimited
- LTPLanding threshold point
- LTTLandline teletypewriter
- LVLight and variable (relating to wind)
- LVELeave or leaving
- LVLLevel
- LVPLow visibility procedures
- LYRLayer or layered
M
- MMetres (preceded by figures)
- MAAMaximum authorized altitude
- MAGMagnetic
- MAHFMissed approach holding fix
- MAINTMaintenance
- MAPAeronautical maps and charts
- MAPTMissed approach point
- MARAt sea
- MASManual Al simplex
- MATFMissed approach turning fix
- MAXMaximum
- MAYMay
- MBSTMicroburst
- MCAMinimum crossing altitude
- MCWModulated continuous wave
- MDAMinimum descent altitude
- MDFMedium frequency direction-finding station
- MDHMinimum descent height
- MEAMinimum en-route altitude
- MEHTMinimum eye height over threshold (for visual approach slope indicator systems)
- METMeteorological or meteorology
- METARAerodrome routine meteorological report (in meteorological code)
- METREPORTLocal routine meteorological report (in abbreviated plain language)
- MFMedium frequency [300 to 3 000 kHz]
- MHDFMedium and high frequency directionfinding stations (at the same location)
- MHVDFMedium, high and very high frequency direction-finding stations (at the same location)
- MHZMegahertz
- MIDMid-point (related to RVR)
- MIFGShallow fog
- MILMilitary
- MNMMinimum
- MNPSMinimum navigation performance specifications
- MNTMonitor or monitoring or monitored
- MNTNMaintain
- MOAMilitary operating area
- MOCMinimum obstacle clearance (required)
- MOCAMinimum obstacle clearance altitude
- MODModerate (used to indicate the intensity of weather phenomena, interference or static reports, e.g. MODRA = moderate rain)
- MONAbove mountains
- MOPSMinimum operational performance standards
- MORMandatory Occurrence Report
- MOVMove or moving or movement
- MPSMetres per second
- MRAMinimum reception altitude
- MRGMedium range
- MRPATS/MET reporting point
- MSMinus
- MSAMinimum sector altitude
- MSASMulti- functional transport satellite (MTSAT) satellite-based augmentation system
- MSAWMinimum safe altitude warning
- MSGMessage
- MSLMean sea level
- MSRMessage . . . (transmission identification) has been misrouted (to be used in AFS as a procedure signal)
- MSSRMonopulse secondary surveillance radar
- MTMountain
- MTUMetric units
- MTWMountain waves
- MVDFMedium and very high frequency direction- finding stations (at the same location)
- MWOMeteorological watch office
- MXMixed type of ice formation (white and clear)
N
- NNo distinct tendency (in RVR during previous 10 minutes)
- NADPNoise abatement departure procedure
- NASCNational AIS system centre
- NATNorth Atlantic
- NAVNavigation
- NBNorthbound
- NBFRNot before
- NCNo change
- NCDNo cloud detected (used in automated METAR/SPECI)
- NDBNon-directional radio beacon
- NDVNo directional variations available (used in automated METAR/SPECI)
- NENorth-east
- NEBNorth-eastbound
- NEGNo or negative or permission not granted or that is not correct
- NGTNight
- NILNone or I have nothing to send to you
- NMNautical miles
- NMLNormal
- NNNo name, unnamed
- NNENorth-north-east
- NNWNorth-north-west
- NONo (negative) (to be used in AFS as a procedure signal)
- NOFInternational NOTAM office
- NOSIGNo significant change (used in trend-type
- NOTAMA notice distributed by means of telecommuni-cation 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
- NOVNovember
- NOZNormal operating zone
- NPANon-precision approach
- NRNumber
- NRHNo reply heard
- NSNimbostratus
- NSCNil significant cloud
- NSENavigation system error
- NSWNil significant weather
- NTLNational
- NTZNo transgression zone
- NWNorth-west
- NWBNorth-westbound
- NXTNext
O
- O/ROn request
- OACOceanic area control centre
- OASObstacle assessment surface
- OBSObserve or observed or observation
- OBSCObscure or obscured or obscuring
- OBSTObstacle
- OCAObstacle clearance altitude
- OCCOcculting (light)
- OCHObstacle clearance height
- OCNLOccasional or occasionally
- OCSObstacle clearance surface
- OCTOctober
- OFZObstacle free zone
- OGNOriginate (to be used in AFS as a procedure signal)
- OHDOverhead
- OISObstacle identification surface
- OKWe agree or It is correct (to be used in
- OLDIOn-line data interchange
- OMOuter marker
- OPAOpaque, white type of ice formation
- OPCControl indicated is operational control
- OPMETOperational meteorological (information)
- OPNOpen or opening or opened
- OPROperator or operate or operative or operating or operational
- OPSOperations
- ORDOrder
- OSVOcean station vessel
- OTPOn top
- OTSOrganized track system
- OUBDOutbound
- OVCOvercast
P
- PProhibited area (followed by identification)
- PAPrecision approach
- PALSPrecision approach lighting system (specify category)
- PANSProcedures for air navigation services
- PAPIPrecision approach path indicator
- PARPrecision approach radar
- PARLParallel
- PATCPrecision approach terrain chart (followed by name/title)
- PAXPassenger(s)
- PBNPerformance-based navigation
- PCDProceed or proceeding
- PCLPilot-controlled lighting
- PCNPavement classification number
- PDCPre-departure clearance
- PDGProcedure design gradient
- PERPerformance
- PERMPermanent
- PIBPre-flight information bulletin
- PJEParachute jumping exercise
- PLIce pellets
- PLAPractice low approach
- PLNFlight plan
- PLVLPresent level
- PNPrior notice required
- PNRPoint of no return
- PODust/sand whirls (dust devils)
- POBPersons on board
- POSSPossible
- PPIPlan position indicator
- PPRPrior permission required
- PPSNPresent position
- PRFGAerodrome partially covered by fog
- PRIPrimary
- PRKGParking
- PROBProbability
- PROCProcedure
- PROVProvisional
- PRPPoint-in-space reference point
- PSPlus
- PSGPassing
- PSNPosition
- PSPPierced steel plank
- PSRPrimary surveillance radar
- PSYSPressure system(s)
- PTNProcedure turn
- PTSPolar track structure
- PWRPower
Q
- QDDo you intend to ask me for a series of bearings? or I intend to ask you for a series of bearings (to be used in radiotelegraphy as a Q Code)
- QDMMagnetic heading (zero wind)
- QDRMagnetic bearing
- QFEAtmospheric pressure at aerodrome elevation (or at runway threshold)
- QFUMagnetic orientation of runway
- QGEWhat is my distance to your station? or Your distance to my station is (distance figures and units) (to be used in radiotelegraphy as a Q Code)
- QJHShall I run my test tape/a test sentence? or Run your test tape/a test sentence (to
- QNHAltimeter sub-scale setting to obtain elevation when on the ground
- QSPWill you relay to . . . free of charge? or I will relay to . . . free of charge (to be used in AFS as a Q Code)
- QTAShall I cancel telegram number . . .? or Cancel telegram number . . . (to be used in AFS as a Q Code)
- QTETrue bearing
- QTFWill you give me the position of my station according to the bearings taken by the D/F stations which you control? or The position of your station according to the bearings taken by the D/F stations that I control was . . . latitude . . . longitude (or other indication of position), class . . . at . . . hours (to be used in radiotelegraphy as a Q Code)
- QUADQuadrant
- QUJWill you indicate the TRUE track to reach you? or The TRUE track to reach me
R
- RRestricted area (followed by identification)
- RARain; Resolution advisory
- RACRules of the air and air traffic services
- RAGRagged; Runway arresting gear
- RAIRunway alignment indicator
- RAIMReceiver autonomous integrity monitoring
- RASCRegional AIS system centre
- RASSRemote altimeter setting source
- RBRescue boat
- RCAReach cruising altitude
- RCCRescue coordination centre
- RCFRadiocommunication failure (message type designator)
- RCHReach or reaching
- RCLRunway centre line
- RCLLRunway centre line light(s)
- RCLRRecleared
- RCPRequired communication performance
- RDHReference datum height
- RDLRadial
- RDORadio
- RERecent (used to qualify weather phenomena, e.g. RERA = recent rain)
- RECReceive or receiver
- REDLRunway edge light(s)
- REFReference to . . . or refer to . . .
- REGRegistration
- RENLRunway end light(s)
- REPReport or reporting or reporting point
- REQRequest or requested
- RERTERe-route
- RESARunway end safety area
- RFConstant radius arc to a fix
- RGRange (lights)
- RHCRight-hand circuit
- RIFReclearance in flight
- RIMERime (used in aerodrome warnings)
- RITERight (direction of turn)
- RLReport leaving
- RLARelay to
- RLCERequest level change en route
- RLLSRunway lead-in lighting system
- RLNARequest level not available
- RMKRemark
- RNAVArea Navigation
- RNGRadio range
- RNPRequired navigation performance
- ROBEXRegional OPMET bulletin exchange (scheme)
- ROCRate of climb
- RODRate of descent
- ROGERI have received your last transmission
- RONReceiving only
- RPDSReference path data selector
- RPIRadar position indicator
- RPLRepetitive flight plan
- RPLCReplace or replaced
- RPSRadar position symbol
- RPTRepeat or I repeat (to be used in AFS as a procedure signal)
- RQRequest (to be used in AFS as a procedure signal)
- RQMNTSRequirements
- RQPRequest flight plan (message type designator)
- RQSRequest supplementary flight plan (message type designator)
- RRReport reaching
- RRA(or RRB, RRC . . . etc., in sequence) Delayed meteorological message (message type designator)
- RSCRescue sub-centre
- RSCDRunway surface condition
- RSPResponder beacon
- RSREn-route surveillance radar
- RSSRoot sum square
- RTDDelayed (used to indicate delayed meteorological message; message type designator)
- RTERoute
- RTFRadiotelephone
- RTGRadiotelegraph
- RTHLRunway threshold light(s)
- RTNReturn or returned or returning
- RTODAHRejected take-off distance available, helicopter
- RTSReturn to service
- RTTRadioteletypewriter
- RTZLRunway touchdown zone light(s)
- RUTStandard regional route transmitting frequencies
- RVRescue vessel
- RVRRunway visual range
- RVSMReduced vertical separation minimum (300 m (1 000 ft)) between FL 290 and FL 410
- RWYRunway
S
- SSouth or southern latitude
- SASand
- SALSSimple approach lighting system
- SANSanitary
- SAPAs soon as possible
- SARSearch and rescue
- SARPSStandards and Recommended Practices [ICAO]
- SATSaturday
- SATCOMSatellite communication
- SBSouthbound
- SBASSatellite-based augmentation system
- SCStratocumulus
- SCTScattered
- SDStandard deviation
- SDBYStand by
- SDFStep down fix
- SESouth-east
- SEASea (used in connection with sea-surface temperature and state of the sea)
- SEBSouth-eastbound
- SECSeconds
- SECNSection
- SECTSector
- SELCALSelective calling system
- SEPSeptember
- SERService or servicing or served
- SEVSevere (used e.g. to qualify icing and turbulence reports)
- SFCSurface
- SGSnow grains
- SGLSignal
- SHShower (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)
- SHFSuper high frequency [3 000 to 30 000 MHz]
- SIInternational system of units
- SIDStandard instrument departure
- SIFSelective identification feature
- SIGSignificant
- SIGMETInformation concerning en-route weather phenomena which may affect the safety of aircraft operations
- SIMULSimultaneous or simultaneously
- SIWLSingle isolated wheel load
- SKEDSchedule or scheduled
- SLPSpeed limiting point
- SLWSlow
- SMCSurface movement control
- SMRSurface movement radar
- SNSnow
- SNOCLOAerodrome closed due to snow (used in METAR/SPECI)
- SNOWTAMSpecial 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
- SOCStart of climb
- SPECIAerodrome special meteorological report (in meteorological code)
- SPECIALLocal special meteorological report (in abbreviated plain language)
- SPISpecial position indicator
- SPLSupplementary flight plan (message type designator)
- SPOCSAR point of contact
- SPOTSpot wind
- SQSquall
- SQLSquall line
- SRSunrise
- SRASurveillance radar approach
- SRESurveillance radar element of precision approach radar system
- SRGShort range
- SRRSearch and rescue region
- SRYSecondary
- SSSandstorm; Sunset
- SSBSingle sideband
- SSESouth-south-east
- SSRSecondary surveillance radar
- SSTSupersonic transport
- SSWSouth-south-west
- STStratus
- STAStraight-in approach
- STARStandard instrument arrival
- STDStandard
- STFStratiform
- STNStation
- STNRStationary
- STOLShort take-off and landing
- STSStatus
- STWLStopway light(s)
- SUBJSubject to
- SUNSunday
- SUPSupplement (AIP Supplement)
- SUPPSRegional supplementary procedures
- SVCService message
- SVCBLServiceable
- SWSouth-west
- SWBSouth-westbound
- SWYStopway
T
- TTemperature
- TATraffic advisory
- TA/HTurn at an altitude/height
- TAATerminal arrival altitude
- TACANUHF tactical air navigation aid
- TAFAerodrome forecast (in meteorological code)
- TAILTail wind
- TARTerminal area surveillance radar
- TASTrue airspeed
- TAXTaxiing or taxi
- TCTropical cyclone
- TCACTropical cyclone advisory centre
- TCASRATraffic alert and collision avoidance system resolution advisory
- TCHThreshold crossing height
- TCUTowering cumulus
- TDOTornado
- TDZTouchdown zone
- TECRTechnical reason
- TELTelephone
- TEMPOTemporary or temporarily
- TFTrack to fix
- TFCTraffic
- TGLTouch-and-go landing
- TGSTaxiing guidance system
- THRThreshold
- THRUThrough
- THUThursday
- TIBATraffic information broadcast by aircraft
- TILUntil
- TIPUntil past . . . (place)
- TKOFTake-off
- TLTill (followed by time by which weather change is forecast to end)
- TLOFTouchdown and lift-off area
- TMATerminal control area
- TNMinimum temperature (followed by figures in TAF)
- TNATurn altitude
- TNHTurn height
- TOTo . . . (place)
- TOCTop of climb
- TODATake-off distance available
- TODAHTake-off distance available, helicopter
- TOPCloud top
- TORATake-off run available
- TOXToxic
- TPTurning point
- TRTrack
- TRATemporary reserved airspace
- TRANSTransmits or transmitter
- TRENDTrend forecast
- TRLTransition level
- TROPTropopause
- TSThunderstorm (followed by RA = rain, SN = snow, PL = ice pellets, GR = hail, GS = small hail and/or snow pellets or combinations thereof, e.g. TSRASN = thunderstorm with rain and snow); Thunderstorm (in aerodrome reports and
- TSUNAMITsunami (used in aerodrome warnings)
- TTTeletypewriter
- TUETuesday
- TURBTurbulence
- TVASIST visual approach slope indicator system
- TVORTerminal VOR
- TWRAerodrome control tower or aerodrome control
- TWYTaxiway
- TWYLTaxiway-link
- TXMaximum
- TYPType of aircraft
- TYPHTyphoon
U
- UUpward (tendency in RVR during previous 10 minutes)
- UAUnmanned aircraft
- UABUntil advised by . . .
- UACUpper area control centre
- UARUpper air route
- UASUnmanned aircraft system
- UDFUltra high frequency direction-finding station
- UFNUntil further notice
- UHDTUnable higher due traffic
- UHFUltra high frequency [300 to 3 000 MHz]
- UICUpper information centre
- UIRUpper flight information region
- ULRUltra long range
- UNAUnable
- UNAPUnable to approve
- UNLUnlimited
- UNRELUnreliable
- UPUnidentified precipitation (used in automated METAR/SPECI)
- USUnserviceable
- UTAUpper control area
- UTCCoordinated Universal Time
V
- VVariations from the mean wind direction
- VAHeading to an altitude; Volcanic ash
- VAACVolcanic ash advisory centre
- VACVisual approach chart (followed by name/title)
- VALIn valleys
- VANRunway control van
- VARMagnetic variation; Visual-aural radio range
- VASISVisual approach slope indicator systems
- VCVicinity of the aerodrome
- VCYVicinity
- VDFVery high frequency direction-finding station
- VERVertical
- VFRVisual flight rules
- VHFVery high frequency [30 to 300 MHz]
- VIHeading to an intercept
- VIPVery important person
- VISVisibility
- VLFVery low frequency [3 to 30 kHz]
- VLRVery long range
- VMHeading to a manual termination
- VMCVisual meteorological conditions
- VNAVVertical Navigation
- VOLMETMeteorological information for aircraft in flight
- VORVHF omnidirectional radio range
- VORTACVOR and TACAN combination
- VOTVOR airborne equipment test facility
- VPAVertical path angle
- VPTVisual manoeuvre with prescribed track
- VRBVariable
- VSABy visual reference to the ground
- VSPVertical speed
- VTFVector to final
- VTOLVertical take-off and landing
- VVVertical visibility (followed by figures in METAR/SPECI and TAF)
W
- WSea-surface temperature (followed by figures in METAR/SPECI)
- WAASWide area augmentation system
- WACWorld Aeronautical Chart
- WAFCWorld area forecast centre
- WBWestbound
- WBARWing bar lights
- WDIWind direction indicator
- WDSPRWidespread
- WEDWednesday
- WEFWith effect from or effective from
- WGS84World Geodetic System
- WIWithin
- WIDWidth or wide
- WIEWith immediate effect or effective immediately
- WILCOWill comply
- WINDWind
- WIPWork in progress
- WKNWeaken or weakening
- WNWWest-north-west
- WOWithout
- WPTWay-point
- WRNGWarning
- WSWind shear
- WSPDWind speed
- WSWWest-south-west
- WTWeight
- WTSPTWaterspout
- WWWWorldwide web
- WXWeather