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[ReneL]

[h3]A [/h3]

A	Amber
A/A	Air-to-air
AAL	Above aerodrome level
ABM	Abeam
ABT	About
ABV	Above
AC	Altocumulus
ACAS	Airborne collision avoidance system
ACC	Area control centre or area control
ACFT	Aircraft
ACK	Acknowledge
ACL	Altimeter check location
ACN	Aircraft classification number
ACPT	Accept or accepted
ACT	Active or activated or activity
AD	Aerodrome
ADA	Advisory area
ADC	Aerodrome chart
ADDN	Addition or additional
ADF	Automatic direction-finding equipment
ADJ	Adjacent
ADR	Advisory route
ADS	Automatic dependent surveillance
ADVS	Advisory service
ADZ	Advise
AFIL	Flight plan filed in the air
AFIS	Aerodrome flight information service
AFM	Yes or affirm or affirmative or that is correct
AFT	After... (time or place)
AFTN	Aeronautical fixed telecommunication network
A/G	Air-to-ground
AGA	Aerodromes, air routes and ground aids
AGL	Above ground level
AGN	Again
AIC	Aeronautical information circular
AIP	Aeronautical information publication
AIRAC	Aeronautical information regulation and control
AIREP	Air-report
AIRMET	Information concerning en-route weather phenomena which may affect the safety of low-level aircraft operations
AIS	Aeronautical information services
ALERFA	Alert phase
ALRS	Alerting service
ALS	Approach lighting system
ALT	Altitude
ALTN	Alternate (aerodrome)
AMA	Area minimum altitude
AMSL	Above mean sea level
ANC	Aeronautical chart 1:500 000 (followed by name/title)
ANCS	Aeronautical navigation chart small scale (followed by name/title and scale)
ANS	Answer
AOC	Aerodrome obstacle chart (followed by type and name/title)
AP	Airport
APAPI	Abbreviated precision approach path indicator
APCH	Approach
APDC	Aircraft parking/docking chart (followed by name/title)
APN	Apron
APP	Approach control office or approach control or approach control service
APR	April
APRX	Approximate or approximately
APSG	After passing
APV	Approve or approved or approval
ARC	Area chart
ARNG	Arrange
ARO	Air traffic services reporting office
ARP	Aerodrome reference point
ARR	Arrive or arrival
ARST	Arresting (specify (part of) aircraft arresting equipment)
AS	Altostratus
ASC	Ascend to or ascending to
ASDA	Accelerate-stop distance available
ASPEEDG	Airspeed gain
ASPEEDL	Airspeed loss
ASPH	Asphalt
AT	At (followed by time at which weather change is forecast to occur)
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
ATP	At... (time or place)
ATS	Air traffic services
ATTN	Attention
AT-VASIS	Abbreviated T visual approach slope indicator system
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

[h3]B[/h3]

B	Blue
BA	Braking action
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
BR	Mist
BRF	Short (used to indicate the type of approach desired or required)
BRG	Bearing
BRKG	Breaking
BTL	Between layers
BTN	Between

[h3]C[/h3]

C	Centre (preceded by runway designation number to identify a parallel runway)
C	Degrees Celsius (Centigrade)
CAT	Category
CAT	Clear air turbulence
CAVOK	Visibility, cloud and present weather better than prescribed values or conditions
CB	Cumulonimbus
CC	Cirrocumulus
CCA	(or CCB, CCC. .. etc., in sequence) Corrected meteorological message
CD	Candela
CDN	Coordination (message type designator)
CF	Change frequency to . . .
CFM	Confirm or I confirm
CGL	Circling guidance light(s)
CH	Channel
CHG	Modification (message type designator)
CI	Cirrus
CIT	Near or over large towns
CIV	Civil
CK	Check
CL	Centre line
CLA	Clear type of ice formation
CLBR	Calibration
CLD	Cloud
CLG	Calling
CLIMB-OUT	Climb-out area
CLR	Clear(s) or cleared to or clearance
CLRD	Runway(s) cleared (used in METAR/SPECI)
CLSD	Close or closed or closing
CM	Centimetre
CMB	Climb to or climbing to
CMPL	Completion or completed or complete
CNL	Cancel or cancelled
CNL	Flight plan cancellation
CNS	Communications, navigation and surveillance
COM	Communications
CONC	Concrete
COND	Condition
CONS	Continuous
CONST	Construction or constructed
CONT	Continue(s) or continued
COOR	Coordinate or coordination
COORD	Coordinates
COP	Change-over point
COR	Correct or correction or corrected
COT	At the coast
COV	Cover or covered or covering
CPDLC	Controller-pilot data link communications
CPL	Current flight plan
CRC	Cyclic redundancy check
CRZ	[wiki]kruissnelheid|Cruise[/wiki]
CS	[wiki]Call sign[/wiki]
CS	Cirrostratus
CTA	Control area
CTAM	Climb to and maintain
CTC	Contact
CTL	Control
CTN	Caution
CTR	Control zone
CU	Cumulus
CUF	Cumuliform
CVR	[wiki]Cockpit voice recorder[/wiki]
CW	Continuous wave
CWY	Clearway

[h3]D[/h3]

D	Downward (tendency in RVR during previous 10 minutes)
D	Danger area (followed by identification)
DA	Decision altitude
D-ATIS	Data link automatic terminal information service
DCKG	Docking
DCP	Datum crossing point
DCPC	Direct controller-pilot communications
DCT	Direct (in relation to flight plan clearances and type of approach)
DEC	December
DEC	Degrees
DEP	Depart or departure
DEP	Departure
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
DIP	Diffuse
DIST	Distance
DIV	Divert or diverting
DLA	Delay or delayed
DLY	Daily
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	Duststorm
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
DUPE	This is a duplicate message
DUR	Duration
D-VOLMET	Data link VOLMET
DVOR	Doppler VOR
DW	Dual wheels
DZ	Drizzle

[h3]E[/h3]

E	East or eastern longitude
EAT	Expected approach time
EB	Eastbound
EDA	Elevation differential area
EEE#	Error
EET	Estimated elapsed time
EFC	Expect further clearance
EGNOS	European geostationary navigation overlay service
EHF	Extremely high frequency [30 000 to 300 000 MHz]
ELBA	Emergency location beacon aircraft
ELEV	Elevation
ELR	Extra long range
ELT	Emergency locator transmitter
EM	Emission
EMBD	Embedded in 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	En-route 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
ETA	Estimated time of arrival or estimating arrival
ETD	Estimated time of departure or estimating departure
ETO	Estimated time over significant point
EV	Every
EXC	Except
EXER	Exercises or exercising or to exercise
EXP	Expect or expected or expecting
EXTD	Extend or extending

[h3]F[/h3]

F	Fixed
FAC	Facilities
FAF	Final approach fix
FAL	Facilitation of international airtransport
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
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)
FMS	Flight management system
FMU	Flow management unit
FNA	Final approach
FPAP	Flight path alignment point
FPL	Filed flight plan
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	[wiki]voet|Feet[/wiki] (dimensional unit)
FTP	Fictitious threshold point
FU	Smoke
FZ	Freezing
FZDZ	Freezing drizzle
FZFG	Freezing fog
FZRA	Freezing rain

[h3]G[/h3]

G	Green
G	Variations from the mean wind speed (gusts) (followed by figures in METAR/SPECI and TAP)
GA	Go ahead, resume sending
G/A	Ground-to-air
G/A/G	Ground-to-air and air-to-ground
GAGAN	GPS and geostationary earth orbit augmented navigation
GAMET	Area forecast for low-level flights
GARP	GBAS azimuth reference point
GBAS	Ground-based augmentation system
GCAJ	Ground controlled approach system or ground controlled approach
GEN	General
GEO	Geographic or true
GES	Ground earth station
GLD	[wiki]zweefvliegtuig|Glider[/wiki]
GLONASS	Global orbiting navigation satellite system
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
GRAS	Ground-based regional augmentation system
GRASS	Grass landing area
GRIB	Processed meteorological data in the form of grid point values expressed in binary form
GRVL	Gravel
GS	[wiki]grondsnelheid|Ground speed[/wiki]
GS	Small hail and/or snow pellets
GUND	Geoid undulation

[h3]H[/h3]

H	High pressure area or the centre of high pressure
H24	Continuous day and night service
HAPI	Helicopter approach path indicator
HBN	Hazard beacon
HDF	High frequency direction-finding station
HDG	Heading
HEL	[wiki]Helikopter|Helicopter[/wiki]
HF	High frequency [3 000 to 30 000 kHz]
HOT	Height or height above
HJ	Sunrise to sunset
HLDG	Holding
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
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)

[h3]I[/h3]

IAC	Instrument approach chart (followed by name/title)
IAF	Initial approach fix
IAO	In and out of clouds
IAP	Instrument approach procedure
IAR	Intersection of air routes
IAS	Indicated airspeed
IBN	Identification beacon
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
IFF	[wiki]IFF|Identification friend/foe[/wiki]
IFR	[wiki]Instrument flight rules[/wiki]
IGA	International general aviation
ILS	[wiki]Instrument landing system[/wiki]
IM	Inner marker
IMC	Instrument meteorological conditions
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
ISOL	Isolated

[h3]J[/h3]

JAN	January
JTST	Jet stream
JUL	July
JUN	June

[h3]K[/h3]

KG	Kilograms
KHZ	Kilohertz
KM	Kilometres
KMH	Kilometres per hour
KPA	Kilopascal
KT	[wiki]knoop|Knots[/wiki]
KW	Kilowatts

[h3]L[/h3]

L	Left (preceded by runway designation number to identify a parallel runway)
L	Locator (see LM, LO )
L	Low pressure area or the centre of low pressure
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 300 kHz]
LGT	Light or lighting
LGTD	Lighted
LIH	Light intensity high
LIL	Light intensity low
LIM	Light intensity medium
LLZ	Localizer
LM	Locator, middle
LMT	Local mean time
LNG	Long (used to indicate the type of approach desired or required)
LO	Locator, outer
LOG	Local or locally or location or located
LONG	Longitude
LORAN	LORAN (long range air navigation system)
LRG	Long range
LTD	Limited
LTP	Landing threshold point
LV	Light and variable (relating to wind)
LVE	Leave or leaving
LVL	Level
LYR	Layer or layered

[h3]M[/h3]

M	[wiki]Mach|Mach number[/wiki] (followed by figures)
M	Metres (preceded 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
MAX	Maximum
MAY	May
MBST	Microburst
MCA	Minimum crossing altitude
MCW	Modulated continuous wave
MDA	Minimum descent altitude
MDF	Medium frequency direction-finding station
MDH	Minimum descent height
MEA	Minimum en-route altitude
MEHT	Minimum eye height over threshold (for visual approach slope indicator systems)
MET	Meteorological or meteorology
METAR	Aerodrome routine meteorological report (in meteorological code)
MET REPORT	Local routine meteorological report (in abbreviated plain language)
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 stations (at the same location)
MHZ	Megahertz
MID	Mid-point (related to R VR)
MIFG	Shallow fog
MIL	Military
MIN	Minutes
MKR	Marker radio beacon
MLS	Microwave landing system
MM	Middle marker
MNM	Minimum
MNPS	Minimum navigation performance specifications
MNT	Monitor or monitoring or monitored
MNTN	Maintain
MOA	Military operating area
MOC	Minimum obstacle clearance (required)
MOD	Moderate (used to indicate the intensity of weather phenomena, interference or static reports, e.g. MODRA = moderate rain)
MON	Above mountains
MON	Monday
MOPS	Minimum operational performance standards
MOV	Move or moving or movement
MPS	Metres per second
MRA	Minimum reception altitude
MRG	Medium range
MRP	ATS/MET reporting point
MS	Minus
MSA	Minimum sector altitude
MSAS	Multifunctional transport satellite (MTSAT) satellite-based augmentation system
MSAW	Minimum safe altitude warning
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)
MX	Mixed type of ice formation (white and clear)

[h3]N[/h3]

N	No distinct tendency (in RVR during previous 10 minutes)
N	North or northern latitude
NASC	National AIS system centre
NAT	North Atlantic
NAV	Navigation
NB	Northbound
NBFR	Not before
NC	No change
NCD	No cloud detected (used in automated METAR/SPECI)
NDB	Non-directional radio beacon
NDV	No directional variations available (used in automated METAR/SPECI)
NE	North-east
NEB	North-eastbound
NEG	No or negative or permission not granted or that is not correct
NGT	Night
NIL	None or I have nothing to send to you
NM	[wiki]mijl|Nautical miles[/wiki]
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-westbound
NXT	Next

[h3]O[/h3]

OAC	Oceanic area control centre
OAS	Obstacle assessment surface
OBS	Observe or observed or observation
OBSC	Obscure or obscured or obscuring
OBST	Obstacle
OCA	Obstacle clearance altitude
OCA	Oceanic control area
OCC	Occulting (light)
OCH	Obstacle clearance height
OCNL	Occasional or occasionally
OCS	Obstacle clearance surface
OCT	October
OFZ	Obstacle free zone
OGN	Originate
OHD	Overhead
OM	Outer marker
OPA	Opaque, white type of ice formation
OPC	Control indicated is operational control
OPMET	Operational meteorological (information)
OPN	Open or opening or opened
OPR	Operator or operate or operative or operating or operational
OPS	Operations
O/R	On request
ORD	Order
OSV	Ocean station vessel
OTLK	Outlook (used in SIGMET messages for volcanic ash and tropical cyclones)
OTP	On top
OTS	Organized track system
OUBD	Outbound
OVC	Overcast

[h3]P[/h3]

P	Maximum value of wind speed or runway visual range (followed by figures in METAR/SPECI and TAP)
P	Prohibited area (followed by identification)
PA	Precision approach
PALS	Precision approach lighting system
PANS	Procedures for air navigation services
PAPI	Precision approach path indicator
PAR	Precision approach radar
PARL	Parallel
PATC	Precision approach terrain chart (followed by name/title)
PAX	Passenger(s)
PCD	Proceed or proceeding
PCL	Pilot-controlled lighting
PCN	Pavement classification number
PDC	Pre-departure clearance
PDG	Procedure design gradient
PER	Performance
PERM	Permanent
PIB	Pre-flight information bulletin
PJE	Parachute jumping exercise
PL	Ice pellets
PLA	Practice low approach
PLN	Flight plan
PLVL	Present level
PN	Prior notice required
PNR	Point of no return
PO	Dust/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
PSR	Primary surveillance radar
PSYS	Pressure system(s)
PTN	Procedure turn
PTS	Polar track structure
PWR	Power

[h3]Q[/h3]

QDL	Do 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)
QDM	Magnetic heading (zero wind)
QDR	Magnetic bearing
QFE	Atmospheric pressure at aerodrome elevation (or at runway threshold)
QFU	Magnetic orientation of runway
QGE	What 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)
QNH	Altimeter sub-scale setting to obtain elevation when on the ground
QTE	True bearing
QTF	Will 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 . . . a t . . . hours (to be used in radiotelegraphy as a Q Code)
QUAD	Quadrant
QUJ	Will you indicate the TRUE track to reach you? Or The TRUE track to reach me is ... degrees a t . . hours (to be used in radiotelegraphy as a Q Code)

[h3]R[/h3]

R	Right (preceded by runway designation number to identify a parallel runway)
R	Red
R	Restricted area (followed by identification)
R	Runway visual range (followed by figures in METAR/SPECI)
RA	Rain
RAC	Rules of the air and air traffic services
RAG	Ragged
RAG	Runway arresting gear
RAI	Runway alignment indicator
RAIM	Receiver autonomous integrity monitoring
RASC	Regional AIS system centre
RASS	Remote altimeter setting source
RB	Rescue boat
RCA	Reach cruising altitude
RCC	Rescue coordination centre
RCF	Radiocommunication failure (message type designator)
RCH	Reach or reaching
RCL	Runway centre line
RCLL	Runway centre line light(s)
RCLR	Recleared
RDH	Reference datum height
RDL	Radial
RDO	Radio
RE	Recent (used to qualify weather phenomena, e.g. RERA = recent rain)
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
RMAC	Radar minimum altitude chart
RMK	Remark
RNAV	Area navigation
RNG	Radio range
RNP	Required navigation performance
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 position symbol
RQMNTS	Requirements
RQP	Request flight plan
RQS	Request supplementary flight plan (message type designator)
RR	Report reaching
RRA	(or RRB, RRC... etc., in sequence) Delayed meteorological message (message type designator)
RSC	Rescue sub-centre
RSCD	Runway surface condition
RSP	Responder beacon
RSR	En-route surveillance radar
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 separation minimum (300 m (1 000 ft)) between FL 290 and FL 410
RWY	[wiki]startbaan|Runway[/wiki]

[h3]S[/h3]

S	State of the sea (followed by figures in METAR/SPECI)
S	South or southern latitude
SA	Sand
SALS	Simple approach lighting system
SAN	Sanitary
ASAP	As soon as possible
SAR	[wiki]Search and rescue [/wiki]
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
SE	South-east
SEA	Sea (used in connection with sea-surface temperature and state of the sea)
SEB	South-eastbound
SEC	Seconds
SECN	Section
SECT	Sector
SELCAL	Selective calling system
SEP	September
SER	Service or servicing or served
SEV	Severe (used e.g. to qualify icing and turbulence reports)
SFC	Surface
SG	Snow grains
SGL	Signal
SH ...	Shower (followed by RA = rain, SN = snow, PL = ice pellets, GR = hail, GS = small hail and/or snow pellets or combinations thereof, e.g. SHRASN = showers of rain and snow)
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 operations
SIMUL	Simultaneous or simultaneously
SKC	Sky clear
SKED	Schedule or scheduled
SLP	Speed limiting point
SLW	Slow
SMC	Surface movement control
SMR	Surface movement radar
SN	Snow
SNOCLO	Aerodrome closed due to snow (used in METAR/SPECI)
SNOWTAM	Special series NOTAM notifying the presence or removal of hazardous conditions due to snow, ice, slush or standing water associated with snow, slush and ice on the movement area, by means of a specific format
SPECI	Aerodrome special meteorological report (in meteorological code)
SPECIAL	Local special meteorological report (in abbreviated plain language)
SPL	Supplementary flight plan (message type designator)
SPOC	SAR point of contact
SPOT	Spot wind
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	Sandstorm
SS	Sunset
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	[wiki]Short take-off and landing[/wiki]
STS	Status
STWL	Stopway light(s)
SUBJ	Subject to
SUN	Sunday
SUP	Supplement (AIP Supplement)
SUPPS	Regional supplementary procedures Service message
SVCBL	Serviceable
SW	South-west
SWB	South-westbound
SWY	Stopway

[h3]T[/h3]

T	Temperature
TA	Transition altitude
TAA	Terminal arrival altitude
TACAN	UHF tactical air navigation aid
TAF	Aerodrome forecast (in meteorological code)
TAIL	[wiki]staartwind|Tail wind[/wiki]
TAR	Terminal area surveillance radar
TAS	[wiki]luchtsnelheid|True airspeed[/wiki]
TAX	Taxiing or taxi
TC	Tropical cyclone
TCAC	Tropical cyclone advisory centre
TCAS	Traffic Collision Avoidance System
TCU	Towering cumulus
TDO	Tornado
TDZ	Touchdown zone
TECR	Technical reason
TEL	Telephone
TEMPO	Temporary or temporarily
TFC	Traffic
TGL	[wiki]Touch-and-go[/wiki] 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 forecast to end)
TLOF	Touchdown and lift-off area
TMA	Terminal control area
TN . . .	Minimum temperature (followed by figures in TAP)
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
TREND	Trend forecast
TRL	Transition level
TROP	Tropopause
TS	Thunderstorm (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, PL = ice pellets, GR = hail, GS = small hail and/or snow pellets or combinations thereof, e.g. TSRASN = thunderstorm with rain and snow)
TUE	Tuesday
TURB	[wiki]turbulentie|Turbulence[/wiki]
T-VASIS	T visual approach slope indicator system
TVOR	Terminal VOR
TWR	Aerodrome control tower or aerodrome control
TWY	Taxiway
TWYL	Taxiway-link
TX...	Maximum temperature (followed by figures in TAP)
TXT	Text
TYP	Type of aircraft
TYPH	Typhoon

[h3]U[/h3]

U	Upward (tendency in RVR during previous 10 minutes)
UAB	Until advised by . .
UAC	Upper area control centre
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 flight information region
ULR	Ultra long range
UNA	Unable
UNAP	Unable to approve
UNL	Unlimited
UNREL	Unreliable
UP	Unidentified precipitation (used in automated METAR/SPECI)
U/S	Unserviceable
UTA	Upper control area
UTC	Coordinated Universal Time

[h3]V[/h3]

V	Variations from the mean wind direction (preceded and followed by figures in METAR/SPECI, e.g. 350V070)
VA	Volcanic ash
VAAC	Volcanic ash advisory centre
VAC	Visual approach chart (followed by name/title)
VAL	In valleys
VAN	Runway control van
VAR	Magnetic variation
VAR	Visual-aural radio range
VASIS	Visual approach slope indicator systems
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	[wiki]Visual flight rules[/wiki]
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
VPA	Vertical path angle
VRB	Variable
VSA	By visual reference to the ground
VSP	Vertical speed
VTOL	[wiki]Vertical take-off and landing[/wiki]
VV...	Vertical visibility (followed by figures in METAR/SPECI and TAP)

[h3]W[/h3]

W	West or western longitude
W	White
W	Sea-surface temperature (followed by figures in METAR/SPECI)
WAAS	Wide area augmentation system
WAC	World Aeronautical Chart ICAO 1:1 000 000 (folio-wed by name/title)
WAFC	World area forecast centre
WB	Westbound
WBAR	Wing bar lights
WDI	Wind direction indicator
WDSPR	Widespread
WED	Wednesday lasagna day
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	Worldwide Web
WX	Weather

[h3]X[/h3]

X	Cross
XBAR	Crossbar (of approach lighting system)
XNG	Crossing
XS	Atmospherics

[h3]Y[/h3]

Y	Yellow
YCZ	Yellow caution zone (runway lighting)
YR	Your

[h3]Z[/h3]

Z(ulu)

Coordinated Universal Time (in meteorological messages)