GEN 2.2  Abbreviations used in AIS publications

Abbreviations marked by an asterisk (*) are either different from or not contained in ICAO Doc 8400.

† When radiotelephony is used, the abbreviations and terms are transmitted as spoken words.

‡ When radiotelephony is used, the abbreviations and terms are transmitted using the individual letters in non-phonetic form.
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
AAmber
A/AAir-to-air
A/GAir-to-ground
AAA(or AAB, AAC...etc., in sequence) Amended meteorological message (message type designator)
AALAbove aerodrome level
ABMAbeam
ABNAerodrome beacon
ABTAbout
ABVAbove
ACAltocumulus
ACASAirborne collision avoidance system
ACCArea control centre or area control
ACCIDNotification 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
ADDNAddition or additional
ADFAutomatic direction finding equipment
ADIZ(to be pronounced _AY-DIZ_) Air defence identification zone
ADJAdjacent
ADRAdvisory route
ADSAutomatic dependent surveillance
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
AGAAerodrome, air routes and ground aids
AGLAbove ground level
AGNAgain
AICAeronautical information circular
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)
ALTNAlternate (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
AMSSAerodrome mobile satellite service
ANSAnswer
AOCAerodrome obstacle chart
APAirport
APCHApproach
APPApproach control office or approach control or approach control service
APRApril
APRXApproximate or approximately
APSGAfter passing
APVApprove or approved or approval
ARFORArea forecast (in aeronautical meteorological code)
ARNGArrange
AROAir traffic services reporting office
ARPAerodrome reference point
ARPAir-report (message type designator)
ARQAutomatic error correction
ARRArrive or arrival
ARRArrival (message type designator)
ARSSpecial air-report (message type designator)
ARSTArresting (specify (part of) aircraft arresting equipment)
ASAltostratus
ASCAscent to or ascending to
ASDAAccelerate stop distance available
ASPHAsphalt
AT...At (followed by time at which weather change is forecast to occur)
ATAActual time of arrival
ATCAir traffic control (in general)
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
ATZAerodrome traffic zone
AUGAugust
AUTHAuthorized or authorization
AUWAll up weight
AUXAuxiliary
AVASISAbbreviated visual approach slope indicator system
AVBLAvailable or availability
AVGAverage
AVGASAviation gasoline
AWTAAdvise at what time able
AWYAirway
AZMAzimuth
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
BBlue
BABraking action
BASECloud base
BCFGFog patches
BCNBeacon (aeronautical ground light)
BCSTBroadcast
BDRYBoundary
BECMGBecoming
BFRBefore
BKNBroken
BL...Blowing (followed by DU= dust, SA= sand or SN= snow)
BLDGBuilding
BLOBelow clouds
BLWBelow ...
*BMCTBeginning of morning civil twilight
BOMBBombing
BRMist
BRFShort (used to indicate the type of approach desired or required)
BRGBearing
BRKGBraking
BSCommercial broadcasting station
BTLBetween layers
BTNBetween
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
CCentre (runway identification)
CDegrees celsius (Centigrade)
CATCategory
CATClear air turbulence
CAVOK(to be pronounced _KAV-OH-KAY_) visibility, cloud and present weather better than prescribed values or conditions
CB(to be pronounced _CEE BEE_) Cumulonimbus
CCCirrocumulus
CCA(or CCB, CCC....etc.. in sequence) corrected meteorological message (message type designator)
CDCandela
CDNCo-ordination (message type designator)
CFChange frequency to ...
CGLCircling guidance light(s)
CHChannel
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
CLRClear(s) or cleared to ... or clearance
CLSDClose or closed or complete
CMCentimetre
CMBClimb to or climbing to
CMPLCompletion or completed or complete
CNLCancel or cancelled
CNLFlight plan cancellation message (message type designator)
CNSCommunication, navigation and surveillance
COMCommunications
CONCConcrete
CONDCondition
CONSContinuous
CONSTConstruction or constructed
CONTContinue or continued
COORCo-ordinate or coordination
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)
CRZCruise
CSCirrostratus
CTAControl area
CTAMClimb to and maintain
CTCContact
CTLControl
CTNCaution
CTRControl zone
CUCumulus
CUFCumuliform
CUSTCustoms
CWContinuous wave
CWYClearway
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
DDownward (tendency in RVR during previous 10 minutes)
D...Danger area (followed by identification)
DADecision altitude
DCDDouble channel duplex
DCKGDocking
DCSDouble channel simplex
DCTDirect (in relation to flight plan clearances and type of approach)
DECDecember
DEGDegrees
DEPDepart or departure
DEPDeparture (message type designator)
DERDeparture end of runway
DESDescend to or descending to
DESTDestination
DETRESFADistress phase
DEVDeviation or deviating
DFTIDistances from touch down indicator
DHDecision height
DIFDiffuse
DISTDistance
DIVDivert or diverting
DLADelay (message type designator)
DLADelay or delayed
DMEDistance measuring equipment
DNGDanger or dangerous
DOMDomestic
DPDew point temperature
DPTDepth
DRDead reckoning
DR...Low drifting (followed by DU= dust, SA= sand or SN = snow)
DRGDuring
DSDust storm
DSBDouble sideband
DTAMDescend to and maintain
DTGDate-time group
DTRTDeteriorate or deteriorating
DTWDual tandem wheels
DUDust
DUCDense upper cloud
DURDuration
DVORDoppler VOR
DWDual wheels
DZDrizzle
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
EEast or eastern longitude
EATExpected approach time
EBEastbound
*EECTEnd of evening civil twilight
EETEstimated elapsed time
EFCExpect further clearance
EHFExtremely high frequency (30 000 to 300 000 MHz)
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
EOBTEstimated off-block time
EQPTEquipment
ESEEast south east
ESTEstimate or estimated or estimate (as message type designator)
ETAEstimated time of arrival or estimating arrival
ETDEstimated time of departure or estimating departure
ETOEstimated time over significant point
EVEvery
EXCExcept
EXERExercises or exercising or to exercise
EXPExpect or expected or expecting
EXTDExtend 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
FFixed
FACFacilities
FAFFinal approach fix
FALFacilitation of international air transport
FAPFinal approach point
FATOFinal approach and take-off area
FAXFacsimile transmission
FBLLight (used to indicate the intensity of weather phenomena, interference or static reports, e.g. FBL RA = light rain)
FCFunnel cloud (tornado or water spout)
FCSTForecast
FCTFriction coefficient
FEBFebruary
FEWFew
FGFog
FICFlight information centre
FIRFlight information region
FISFlight information service
FISAAutomated flight information service
FLFlight level
FLDField
FLGFlashing
*FLOSFlight Level Orientation Scheme
FLRFlares
FLTFlight
FLTCKFlight check
FLUCFluctuating or fluctuation or fluctuated
FLWFollow(s) or following
FLYFly or flying
FMFrom
FM ...From (followed by time weather change is forecast to begin)
FMUFlow management unit
FNAFinal approach
FPLFiled flight plan (message type designator)
FPMFeet per minute
FPRFlight plan route
FRFuel remaining
*FRAFree Route Airspace
FREQFrequency
FRIFriday
FRNGFiring
FRONTFront (relating to weather)
FRQFrequent
FSLFull stop landing
FSSFlight service
FSTFirst
FTFeet (dimensional unit)
FUSmoke
FZFreezing
FZDZFreezing drizzle
FZFGFreezing fog
FZRAFreezing 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
GGreen
G/AGround-to-air
G/A/GGround-to-air and air-to-ground
GAMETArea forecast for low-level operations
GCAGround controlled approach system or ground controlled approach
GENGeneral
GEOGeographic or true
GESGround earth station
GLDGlider
GNDGround
GNDCKGround check
GNSSGlobal navigation satellite system
GPGlide path
GPSGlobal positioning system
GRHail
GRASSGrass landing area
GRIBProcessed meteorological data in the form of grid point values (aeronautical meteorological code)
GRVLGravel
GSGround speed
GSSmall hail and/or snow pellets
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
H24Continuous day and night service
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
HNSunset to sunrise
HOService available to meet operational requirements
HOLHoliday
HOSPHospital aircraft
HPAHectopascal
HRHours
HSService available during hours of scheduled operations
HURCNHurricane
HVDFHigh and very high frequency direction finding stations (at the same location)
HVYHeavy
HVYHeavy (used to indicate the intensity of weather phenomena, e.g. HVY RA = heavy rain)
HXNo specific working hours
HYRHigher
HZHaze
HZHertz (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
IACInstrument approach chart
IAFInitial approach fix
IAOIn and out of clouds
IARIntersection of air routes
IASIndicated air speed
IBNIdentification beacon
ICDiamond dust (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
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
ISAInternational standard atmosphere
ISBIndependent sideband
ISOLIsolated
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
JANJanuary
JTSTJet stream
JULJuly
JUNJune
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
KGKilograms
KHZKilohertz
KMKilometres
KMHKilometres per hour
KPAKilopascal
KTKnots
KWKilowatts
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
LLeft (runway identification)
LLocator (see LM, LO)
*LALLowest Available Level
LAMLogical acknowledgement (message type designator)
LANInland
LATLatitude
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
LMLocator middle
LMTLocal mean time
LNGLong (used to indicate the type of approach desired or required)
LOLocator, outer
LOCLocalizer
LONGLongitude
LORANLoran (long range air navigation system)
LRGLong range
LTDLimited
LTTLandline teletypewriter
LVLight and variable (relating to wind)
LVELeave or leaving
LVLLevel
LYRLayer 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
MMach number (followed by figures)
MMetres (preceded by figures)
MAAMaximum authorized altitude
MAGMagnetic
MAINTMaintenance
MAPAeronautical maps and charts
MAPTMissed approach point
MARMarch
MARAt sea
MASManual A1 simplex
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 system)
METMeteorological or meteorology
METARAviation routine weather report (in aeronautical meteorological code)
MFMedium frequency (300 kHz to 3 000 kHz)
MHDFMedium and high frequency direction-finding station (at the same location)
MHVDFMedium, high and very high frequency direction-finding station (at the same location)
MHZMegahertz
MIDMid-point (related to RVR)
MIFGShallow fog
MILMilitary
MINMinutes
MKRMarker radio beacon
MLSMicrowave landing system
MMMiddle marker
MNMMinimum
MNPSMinimum navigation performance specifications
MNTMonitor or monitoring or monitored
MNTNMaintain
MOAMilitary operating area
MOCMinimum obstacle clearance (required)
MODmoderate (used to indicate the intensity of weather phenomena, interference or static reports e.g. MOD RA = moderate rain)
MONAbove mountains
MONMonday
MOTNEMeteorological Operational Telecommunications Network Europe
MOVMove or moving or movement
MPSMetres per second
MRAMinimum reception altitude
MRGMedium range
MRPATS/MET reporting point
*MRVAMinimum radar vectoring altitude
MSMinus
MSAMinimum sector altitude
MSGMessage
MSLMean sea level
MTMountain
MTUMetric units
MTWMountain waves
MVDFMedium and very high frequency direction-finding station (at the same location)
MWOMeteorological watch office
MXMixed 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
NNorth or northern latitude
NNo distinct tendency (in RVR during previous 10 minutes)
NATNorth atlantic
NAVNavigation
NBNorth bound
NBFRNot before
NCNo change
NDBNon-directional radio beacon
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
NNENorth north east
NNWNorth north west
NOFInternational NOTAM office
NOSIGNo significant change (used in trend-type landing forecasts)
NOTAMA notice containing information concerning the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel concerned with flight operations
NOVNovember
*NPZNo Planning Zone
NRNumber
NRHNo reply heard
NSNimbostratus
NSCNil significant cloud
NSWNil significant weather
NWNorth-west
NWBNorth-westbound
NXTNext
O - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
O/ROn request
OACOceanic area control centre
OASObstacle assessment surface
OBSObserve or observed or observation
OBSCObserve or obscured or obscuring
OBSTObstacle
OCAObstacle clearance altitude
OCAOceanic control area
OCCOcculting (light)
OCHObstacle clearance height
OCNLOccasional or occasionally
OCSObstacle clearance surface
OCTOctober
OHDOverhead
OMOut marker
OPAOpaque, white type of ice formation
OPCThe control indicated is operational control
OPMETOperational meteorological (information)
OPNOpen or opening or opened
OPROperator or operate or operative or operating or operational
OPSOperations
ORDIndication of an order
OSVOcean station vessel
OTLKOutlook (used in SIGMET message for volcanic ash and tropical cyclones)
OTPOn top
OTSOrganized track system
OUBDOut-bound
OVCOvercast
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)
*P-RNAVPrecision area navigation
PALSPrecision approach lighting system (specify category)
PANSProcedures for air navigation services
PAPIPrecision approach path indicator
PARPrecision approach radar
PARLParallel
PAXPassenger(s)
PCDProceed or proceeding
PCNPavement classification number
PDGProcedure design gradient
PEIce pellets
PERPerformance
PERMPermanent
PJEParachute jumping exercise
PLAPractice low approach
PLNFlight plan
PLVLPresent level
PNPrior notice required
PNRPoint of no return
PODust devils
POBPersons on board
POSSPossible
PPIPlan position indicator
PPRPrior permission required
PPSNPresent position
PRFGAerodrome partially covered by fog
PRIPrimary
PRKGParking
PROBProbability
PROCProcedure
PROVProvisional
PSPlus
PSGPassing
PSNPosition
PSPPierced steel plank
PTNProcedure turn
PTSPolar track structure
PWRPower
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
QBICompulsory IFR flight
QDMMagnetic heading (zero wind)
QDRMagnetic bearing
QFEAtmospheric pressure at aerodrome elevation (or at runway threshold)
QFUMagnetic orientation of runway
QNHAltimeter sub-scale setting to obtain elevation when on the ground
QTETrue bearing
QUADQuadrant
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
RRed
RRight (runway identification)
R ...Restricted area (followed by identification)
RARain
RACRules or the air and air traffic services
*RADRoute Availability Document
RAFCRegional area forecast centre
RAGRagged
RAGRunway arresting gear
RAIRunway alignment indicator
RBRescue boat
RCAReach cruising altitude
RCCRescue co-ordination centre
RCFRadiocommunication failure (message type designator
RCHReach or reaching
RCLRunway centre line
RCLLRunway centre line light(s)
RCLRRecleared
RDHReference datum height (for ILS)
RDLRadial
RDORadio
RE ...Recent (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
RERTEReroute
RGRange (lights)
RIFReclearance in flight
RITERight (direction of turn)
RLReport leaving
RLARelay to
RLCERequest level change en-route
RLLSRunway lead-in lighting system
RLNARequested level not available
RMKRemark
*RMZRadio mandatory zone
RNAV(to be pronounced "AR-NAV") Area navigation
RNGRadio range
RNPRequired navigation performance
ROBEXRegional OPMET bulletin exchange(scheme)
ROCRate of climb
RODRate of descent
ROFORRoute forecast (in aeronautical meteorological code)
RONReceiving only
RPLRepetitive flight plan
RPLCReplace or replaced
RPSRadar position symbol
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
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
RWYRunway
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
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
SCStratocumulus
SCTScattered
SDBYStand by
SESouth-east
SEBSouth-eastbound
SECSeconds
*SECSISouth East Common Sky Initiative
SECTSector
SELCALSelective calling system
SEPSeptember
SERService or servicing or served
SEVSevere (used e.g. to qualify icing and turbulence reports)
SFCSurface
SGSnow grains
SGLSignal
SH ...Showers (followed by RA=rain, SN=snow, PE=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)
SIDStandard instrument departure
SIFSelective identification feature
SIGMETInformation concerning en-route weather phenomena which may affect the safety of operations
SIGWXSignificant weather
SIMULSimultaneous or simultaneously
SIWLSingle isolated wheel load
SKCSky clear
SKEDSchedule or scheduled
SLPSpeed limiting point
SLWSlow
SMCSurface movement control
SMRSurface movement radar
SNSnow
SNOWTAMA 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
SPECIAviation selected special weather report (in aeronautical meteorological code)
SPECIALSpecial meteorological report (in abbreviated plain language)
SPLSupplementary flight plan (message type designator)
SPOCSAR point in 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
SSSunset
SSBSingle sideband
SSESouth south east
SSRSecondary surveillance radar
SSTSupersonic transport
SSWSouth southwest
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 - 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
TTemperature
TATransition altitude
TACANUHF tactical air navigation aid
TAFAerodrome forecast
TAILTail, wind
TARTerminal area surveillance radar
TASTrue airspeed
TAXTaxiing or taxi
TCTropical cyclone
TCUTowering cumulus
TDOTornado
TDZTouchdown zone
TECRTechnical reason
TELTelephone
TEMPOTemporary or temporarily
TENDTrend forecast
TFCTraffic
TGLTouch-and-go landing
TGSTaxiing guidance system
THRThreshold
THRUThrough
THUThursday
TILUntil
TIPUntil past...(place)
TKOFTake off
TL ...Till (followed by time by which weather change is forecast to end)
TLOFTouchdown and lift-off area
TMATerminal control area
*TMZTransponder mandatory zone
TNATurn altitude
TNHTurn height
TOTo...(place)
*TOBTTarget off block time
TOCTop of climb
TODATake-off distance available
TODAHTake-off distance available, helicopter
TOPCloud top
TORATake-off run available
TPTurning point
TRTrack
TRATemporary reserved airspace
TRANSTransmits or transmitter
TRLTransition level
TROPTropopause
TSThunderstorm (in aerodrome reports and forecasts, ts used alone means thunder heard but no precipitation at the aerodrome)
TS...Thunderstorm (followed by RA= RAIN, SN= snow, PE= ice pellets, GR= hail, GS= small hail and/or snow pellets or combinations thereof, e.g. TSRASN= thunderstorm with rain and snow)
TTTeletypewriter
TUETuesday
TURBTurbulence
TVORTerminal VOR
TWRAerodrome control tower or aerodrome control
TWYTaxiway
TWYLTaxiway-link
TXLTaxilane
TYPType of aircraft
TYPHTyphoon
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
UUpward (tendency in rvr during previous 10 minutes)
U/SUnserviceable
UABUntil advised by...
UACUpper area control centre
UARUpper air route
*UAVUnmanned aerial vehicle
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 centre
ULRUltra long range
UNAUnable
UNAPUnable to approve
UNLUnlimited
UNRELUnreliable
UTAUpper control area
UTCCo-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
VAVolcanic ash
VAAC Volcanic ash advisory centre
VACVisual approach chart
VALIn valleys
VANRunway control van
VARMagnetic variation
VARVisual-aural radio range
VASISVisual approach slope indicator system
VCVicinity of the aerodrome (followed by FG=fog, FC=funnel cloud, PO=dust-sand whirls, BLDU=blowing dust, BLSA = blowing sand or BLSN=blowing snow, e.g. VC FG = vicinity fog)
VCYVicinity
VDFVery high frequency direction-finding station
VERVertical
VFRVisual flight rules
VHFVery high frequency (30 to 300 Mhz)
VIPVery important person
VISVisibility
VLFVery low frequency (3 to 30 khz)
VLRVery long range
VMCVisual meteorological conditions
VOLMETMeteorological information for aircraft in flight
VORVHF omnidirectional radio range
VORTACVOR and TACAN combination
VOTVOR airborne equipment test facility
VRBVariable
VSABy visual reference to the ground
VSPVertical speed
VTOLVertical 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
WWest or western longitude
WWhite
WACWorld aeronautical chart-ICAO 1:1 000 000
WAFCWorld area forecast centre
*WAM Wide area multilateration
WBWestbound
WBARWing bar lights
WDIWind direction indicator
WDSPRWidespread
WEDWednesday
WEFWith effect from or effective from
WIWithin
WIDWidth
WIEWith immediate effect or effective immediately
WILCOWill comply
WINTEMForecast upper wind and temperature for aviation
WIPWork in progress
WKNWeaken or weakening
WNWWest north west
WOWithout
WPTWay-point
WRNGWarning
WSWind shear
WSPDWind speed
WSWWest south west
WTWeight
WTSPTWaterspout
WXWeather
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
XCross
XBARCrossbar (of approach lighting system)
XNGCrossing
XSAtmospherics
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
YYellow
YCZYellow caution zone (runway lighting)
YRYour
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
ZCo-ordinated universal time (in meteorological messages)