*Ef skammstöfun er frábrugðin ICAO Doc 8400 eða er ekki tiltekin þar er hún stjörnumerkt.
†Í talfjarskiptum eru skammstafanir og orðalag flutt sem talað orð.
‡Í talfjarskiptum eru skammstafanir og orðalag flutt sem einstakir bókstafir.
A Alpha*
A Amber
A Amperes*
A Auto-tuned NAVAID*
AA All after...*
AAA (or AAB, AAC... etc., in sequence) Amended meteorological message (message type designator)
A/A Air-to-air
AAL Above aerodrome level
AAD Assigned altitude deviation
AAR Air to air refuelling
AAIM Aircraft autonomous integrity monitoring
AB All before...*
ABI Advance boundary information
ABM Abeam
ABN Aerodrome beacon
ABT About
ABV Above
AC Advisory Circular*
AC Alternate Current*
AC Altocumulus
ACARS † (to be pronounced “AY-CARS”) Aircraft communication addressing and reporting system
ACAS † (to be pronounced “AY-CAS”) Airborne collision avoidance system
ACC ‡ Area control centre or area control
ACCID Notification of an aircraft accident
ACFT Aircraft
ACK Acknowledge
ACL Altimeter check location
ACN Aircraft classification number
ACP Acceptance (message type designator)
ACPT Accept 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
ADIZ † Air defence identification zone
ADJ Adjacent
ADR Advisory route
ADS Automatic dependent surveillance*
ADS 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)
ADS-B ‡ Automatic Dependent Surveillance — broadcast
ADS-C ‡ Automatic dependent surveillance — contract
ADSU Automatic dependent surveillance unit
ADVS Advisory service
ADZ Advise
AES Aircraft earth station
AFC Area forecast centre*
AFIL Flight plan filed in the air
AFIS Aerodrome flight information service
AFM Yes or affirm or affirmative or that is correct
AFS Aeronautical fixed service
AFT... After (followed by 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
AIDC Air traffic services interfacility data communications
AIM Aeronautical information management
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
ALA Alighting area
ALERFA † Alert phase
ALR Alerting (message type designator)
ALS Approach lighting system
ALT Altitude
ALTN Alternate or alternating (light alternates in colour)
ALTN Alternate (aerodrome)
AMD Amend or amended
AMDT Amendment (AIP Amendment)
AMS Aeronautical mobile service
AMSL Above mean sea level
AMSS Aeronautical mobile satellite service
ANC... Aeronautical chart — 1:500 000 (followed by name/title)
ANCS... Aeronautical navigation chart — small scale (followed by name/title and scale)
ANS Answer
AO Aircraft operator
AOC... Aerodrome obstacle chart (followed by type and name/title)
AP Airport
APAPI † (to be pronounced “AY-PAPI”) 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
APU Auxiliary power unit
APV Approach procedure with vertical guidance
AR End of transmission*
ARC Area chart
ARFF Aircraft Rescue and Fire Fighting*
ARFOR Area forecast* (in aeronautical meteorological code)
ARMET Forecast upper wind and temperature at specified points* (in aeronautical meteorological code)
ARNG Arrange
ARO Air traffic services reporting office
ARP Aerodrome reference point
ARP Air-report (message type designator)
ARQ Automatic error correction
ARR Arrival (message type designator)
ARR Arrive or arrival
ARS Special air-report (message type designator)
ARST Arresting (specify (part of) aircraft arresting equipment)
AS Altostratus
AS Wait*
ASAP As soon as possible
ASC Ascent to or ascending to
ASDA Accelerate-stop distance available
ASE Altimetry system error
ASHTAM Special 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
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)
ATCSMAC… Air traffic control surveillance minimum altitude chart (followed by name/title)
ATD ‡ Actual time of departure
ATFM Air traffic flow management
ATIS † (to be pronounced “AY-TIS”) Automatic terminal information service
ATM Air traffic management
ATN Aeronautical telecommunication network
ATP… At (followed by time or place)
ATS Air traffic services
ATTN Attention
AT-VASIS † (to be pronounced “AY-TEE-VASIS”) Abbreviated T visual approach slope indicator system
ATZ Aerodrome traffic zone
AUG August
AUTH Authorized or authorization
AUTO Automatic
AUW All up weight
AUX Auxiliary
AVASIS Abbreviated visual approach slope indicator system*
AVBL Available or availability
AVG Average
AVGAS † Aviation gasoline
AWOS Automated weather observation system
AWTA Advise at what time able
AWY Airway
AZM Azimuth
B Blue
B Bravo*
BA Braking action
BARO-VNAV † (to be pronounced “BAA-RO-VEENAV”) Barometric vertical navigation
BASE † Cloud base
BCFG Fog patches
BCN Beacon (aeronautical ground light)
BCST Broadcast
BDRY Boundary
BECMG Becoming
BFR Before
BKN Broken
BL... Blowing (followed by DU = dust, SA = sand or SN = snow)
BLDG Building
BLO Below clouds
BLW Below...
BOMB Bombing
BR Mist
BRF Short (used to indicate the type of approach desired or required)
BRG Bearing
BRKG Braking
BS Commercial broadcasting station
BTL Between layers
BTN Between
BUFR Binary universal form for the representation of meteorological data
C Centre (preceded by runway designation number to identify a parallel runway (...C))
Degrees Celsius (Centigrade)
CA Course to an altitude
CAA Civil aviation authority or civil aviation administration
CAT Category
CAT Clear air turbulence
CAVOK † (to be pronounced “KAV-OH-KAY”)
Visibility, cloud and present weather better than prescribed values or conditions
CB ‡ Cumulonimbus (to be pronounced “CEE BEE”)
CBA Cross Border Area*
CC Cirrocumulus
CCA (or CCB, CCC... etc., in sequence) Corrected meteorological message (message type designator)
CCO Continuous climb operations
CD Candela
CDN Co-ordination (message type designator)
CDO Continuous descent operations
CDR Conditional route
CF Change frequency to...
CF Course to a fix
CFM Confirm or I confirm
CGL Circling guidance light(s)
CH Channel
CH# This is a channel-continuity-check of transmission to permit comparison of your record of channel- sequence numbers of messages received on the channel (to be used in AFS as a procedure signal)
CHEM Chemical
CHG Modification (message type designator)
CI Cirrus
CIDIN † Common ICAO data interchange network
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
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 (message type designator)
CNS Communications, navigation and surveillance
CNS Continuous*
COM Communications
CONC Concrete
COND Condition
CONS Continuous
CONST Construction or constructed
CONT Continue or continued
COOR Coordinate or coordination
COORD Coordinates
COP Change-over point
COR Correct or corrected or correction
(used to indicate corrected meteorological message; message type designator) 
COT At the coast
COV Cover or covered or covering
CP General call to two or more specified stations*
CPDLC ‡ Controller-pilot data link communications
CPL Current flight plan (message type designator)
CRC Cyclic redundancy check
CRM Collision risk model
CRP Compulsory reporting point
CRZ Cruise
CS Call sign
CS Cirrostratus
CTA Control area
CTAM Climb to and maintain
CTC Contact
CTL Control
CTN Caution
CTR Control zone
CU Cumulus
CUF Cumuliform
CUST Customs
CVR Cockpit voice recorder
CW Continuous wave
CWY Clearway
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 (to be pronounced “DEE-ATIS”)
DCD Double channel duplex
DCKG Docking
DCP Datum crossing point
DCPC Direct controller-pilot communications
DCS Double channel simplex
DCT Direct (in relation to flight plan clearances and type of approach)
DE From (used to precede the call sign of the calling station) (to be used in AFS as a procedure signal)
DEC December
DEG Degrees
DENEB Fog dispersal operations*
DEP Depart or departure
DEP Departure (message type designator)
DEPO Deposition
DER Departure end of the runway
DES Descend to or descending to
DEST Destination
DETRESFA  † Distress phase
DEV Deviation or deviating
DF Direction finding
DFDR Digital flight data recorder
DFTI Distance from touchdown indicator
DGPS Differential global positioning system*
DH Decision height
DIF Diffuse
DIST Distance
DIV Divert or Diverting
DLA Delay (message type designator)
DLA Delay or delayed
DLIC Data link initiation capability
DLY Daily
DLM Data Link Manager*
DME ‡ Distance measuring equipment
DNG Danger or dangerous
DOF Date of flight
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
DRSN Low drifting snow*
DSB Double side-band
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 (to be used in AFS as a procedure signal)
DUR Duration
DVOR Doppler VOR
DW Dual wheels
DZ Drizzle

E East or eastern longitude
EAT Expected approach time
EB Eastbound
EDA Elevation differential area
EDTO Extended diversion time operations
EEE# Error (to be used in AFS as a procedure signal)
EET Estimated elapsed time
EFC Expect further clearance
EFIS † Electronic flight instrument system overlay service (to be pronounced “EE-FIS”)
EGNOS † European geostationary navigation (to be pronounced “EGG-NOS”)
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... Enroute chart (followed by name/title)
ENRT En route*
EOBT Estimated off-block time
EQN Equatorial latitudes northern hemisphere
EQPT Equipment
EQS Equatorial latitudes southern hemisphere
ER Here... or herewith*
ESE East-south-east
EST Estimate or estimated or estimation (message type designator)
ETA ‡ Estimated time of arrival or estimating arrival
ETD ‡ Estimated time of departure or estimating departure
ETO Estimated time over significant point
EUR RODEX European regional OPMET data exchange
EV Every
EXC Except
EXER Exercises or exercising or to exercise
EXP Expect or expected or expecting
EXTD Extend or extending
F Fixed
F Degrees Fahrenheit*
FA Course from a fix to an altitude
FAC Facilities
FAF Final approach fix
FAL Facilitation of international air transport
FANS Future Air Navigation Systems*
FAP Final approach point
FAS Final approach segment
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
FCST Forecast
FCT Friction coefficient
FDPS Flight data processing system
FEB February
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 Course from a fix to manual termination (used in navigation database coding)
FM From
FM... From (followed by time at which weather change is forecast to begin)
FMC Flight management computer
FMS ‡ Flight management system
FMU Flow management unit
FNA Final approach
FOT Units of English system*
FPAP Flight path alignment point
FPL Flight plan
FPM Feet per minute
FPR Flight plan route
FR Fuel remaining
FREQ Frequency
FRI Friday
FRNG Firing
FRONT † Front (relating to weather)
FROST † Frost (used in aerodrome warnings)
FRQ Frequent
FSFE FANS services front end*
FSL Full stop landing
FSS Flight service station
FST First
FT Feet (dimensional unit)
FTE Flight technical error
FTP Fictitious threshold point
FTT Flight technical tolerance
FU Smoke
FZ Freezing
FZDZ Freezing drizzle
FZFG Freezing fog
FZRA Freezing rain
G Golf*
G Green
G Wind Gusts*
G... Variations from the mean wind speed (gusts) (followed by figures in METAR/SPECI and TAF)
G/A Ground-to-air
G/A/G Ground-to-air and air-to-ground
GA General aviation
GA Go ahead, resume sending (to be used in AFS as a procedure signal)
GAGAN † GPS and geostationary earth orbit augmented navigation
GAIN Airspeed or headwind gain
GAMET Area forecast for low-level flights
GARP GBAS azimuth reference point 
GAT  General Air Traffic*
GBAS † Ground-based augmentation system (to be pronounced “GEE-BAS”)
GCA ‡ Ground controlled approach system or ground controlled approach
GEN General
GEO Geographic or true
GES Ground earth station
GLD Glider
GLONASS † Global navigation satellite system (to be pronounced “GLO-NAS”)
GLS ‡ GBAS landing system
GMC... Ground movement chart (followed by name/title)
GMT Greenwich mean time*
GND Ground
GNDCK Ground check
GNSS ‡ Global nav. sat. system
GOV Government
GP Glide path
GPA Glide path angle
GPIP Glide path intercept point
GPS ‡ Global positioning system
GPU Ground power unit
GPWS ‡ Ground proximity warning system
GR Hail
GRAS † Ground-based regional augmentation system (to be pronounced “GRASS”)
GP VHF ‡ General purpose very high frequency*
GR Hail or soft hail*
GRAD Minimum required Climb Gradient*
GRADU Gradual or gradually*
GRASS Grass landing area
GRIB Processed meteorological data in the form of grid point values expressed in binary form
(in meteorological code)
GRID Processed meteorological data in the form of grid point values*
(in aeronautical meteorological code)
GRN Green*
GRVL Gravel
GS Ground speed
GS Small hail and/or snow pellets
GUND Geoid undulation
H High pressure area or the centre of high pressure
H... Significant wave height (followed by figures in METAR/SPECI)
H24 Continuous day and night service
HA Holding/racetrack to an altitude
HAPI Helicopter approach path indicator
HBN Hazard beacon
HCH Heliport crossing height
HDF High frequency direction-finding station
HDG Heading
HEL Helicopter
HF Holding/racetrack to a fix
HF ‡ High frequency (3 000 to 30 000 kHz)
HGT Height or height above
HJ Sunrise to sunset
HLA High Level Airspace*
HLDG Holding
HLP Heliport
HLS Helicopter landing site
HM Holding/racetrack to a manual termination
HN Sunset to sunrise
HNH High latitudes northern hemisphere
HO Service available to meet operational requirements
HOL Holiday
HOSP Hospital aircraft
HPA Hectopascal
HR Hours
HRP Heliport reference point
HS Service available during hours of scheduled operations
HSH High latitudes southern hemisphere
HUD Head-up display
HUM Humanitarian
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)
IAC... Instrument approach chart (followed by name/title)
IAF Initial approach fix
IAIP Integrated Aeronautical Information Package*
IAL Instrument approach and landing chart*
IAO In and out of clouds
IAP Instrument approach procedure
IAR Intersection of air routes
IAS Indicated air speed
IBN Identification beacon
ICAO International Civil Aviation Organization
ICE Icing
ID Identifier or identify
IDENT † Identification
IF Intermediate approach fix
IFF Identification friend/foe
IFR ‡ Instrument flight rules
IGA International general aviation
ILS ‡ Instrument landing system
IM Inner marker
IMC ‡ Instrument meteorological conditions
IMG Immigration
IMI Interrogation sign (question mark) (to be used in AFS as a procedure signal)
IMPR Improve or improving
IMT Immediate or immediately
INA Initial approach
INBD Inbound
INC In cloud
INCERFA † Uncertainty phase
INCORP Incorporated
INFO † Information
INOP Inoperative
INP If not possible
INPR In progress
INS Inches (dimensional unit)*
INS Inertial navigation system
INSTL Install or installed or installation
INSTR Instrument
INT Intersection
INTER Intermittent*
INTL International
INTRG Interrogator
INTRP Interrupt or interruption or interrupted
INTSF Intensify or intensifying
INTST Intensity
IR Ice on runway
IRS Inertial reference system
ISA International standard atmosphere
ISB Independent sideband
ISOL Isolated
JAG Jet arresting gear*
JAN January
JM Make a series of dashes if I may transmit*
JM Make a series of dots to stop my transmission*
JRCC Joint Rescue Coordination Centre* Björgunarstjórnstöð sjófarenda og loftfara*
JTST Jet stream
JUL July
JUN June

K Invitation to transmit*
KA Start-of-message signal in Morse telegraphy*
KG Kilograms
KHZ Kilohertz
KIAS Knots indicated airspeed
KM Kilometres
KMH Kilometres per hour
KPA Kilopascal
KT Knots
KW Kilowatts

L Left (preceded by runway designation number to identify a parallel runway (...L))
L Litre
L Locator (see LM, LO)
L Low pressure area or the centre of low pressure
LAM Logical acknowledgement (message type designator)
LAN Inland
LAT Latitude
LB Pounds (weight)*
LCA Local or locally or location or located
LCN Load classification number*
LDA Landing distance available
LDAH Landing distance available, helicopter
LDG Landing
LDI Landing direction indicator
LDIN Lead-In Light System*
LEFT Left (direction of turn)*
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
LINE Line (used in SIGMET)
LLZ Localizer*
LM Locator, middle
LMT Local mean time
LNAV † Lateral navigation (to be pronounced “EL-NAV”)
LNG Long (used to indicate the type of approach desired or required)
LO Locator, outer
LOC Localizer, Locally*, location* or located*
LONG Longitude
LORAN † LORAN (long range air navigation system)
LOSS Airspeed or headwind loss
LPV Localizer performance with vertical guidance
LR The last message received by me was... (to be used in AFS as a procedure signal)
LRG Long range
LS The last message sent by me was... or Last message was... (to be used in AFS as a procedure signal)
LSQ Line squall*
LTA Lower control area
LTD Limited
LTP Landing threshold point
LTT Land-line teletypewriter*
LV Light and variable (relating to wind)
LVE Leave or leaving
LVL Level
LVP Low visibility procedures
LYR Layer or layered
Metres (preceded by figures (...M))
M... Mach number (followed by figures)
M... Minimum value of runway visual range (followed by figures in METAR/SPECI)
MAA Minimum authorized altitude
MAG Magnetic
MAHF Missed approach holding fix
MAINT Maintenance
MALS Medium Intensity Approach Light System*
MALSF MALS with sequenced Flashing lights*
MALSR MALS with Runway alignment indicator*
MAP Aeronautical maps and charts
MAPT Missed approach point
MAPt Missed approach point*
MAR At sea
MAR March
MAS Manual Al simplex*
MATF Missed approach turning fix
MATZ Military aerodrome traffic zone
MAX Maximum
MB Millibars*
MBST Microburst
MC... Multiple copy for delivery to... (number) addressees*
MCA Minimum crossing altitude
MCTR Military control zone
MCW Modulated continuous wave
MDA Minimum descent altitude
MDF Medium frequency direction-finding station
MDH Minimum descent height
MEA Minimum en-route altitude
MEDEVAC Medical evacuation flight
MEHT Minimum eye height over threshold
MET † Meteorological or meteorology
MET REPORT Local routine meteorological report (in abbreviated plain language)
METAR † Aerodrome routine meteorological report (in meteorological code)
MF Medium frequency (300 to 3000 kHz)
MHA Minimum holding altitude
MHDF Medium and high frequency direction-finding stations (at the same location)
MHVDF Medium, high and very high frequency direction-finding station (at the same location)
MHZ Megahertz
MID Mid-point (related to RVR)
MIFG Shallow fog
MIL Military
MIN Minutes
MIS Missing... (transmission identification) (to be used in AFS as a procedure signal)
MKR Marker radio beacon
MLAT Multilateration*
MLS ‡ Microwave landing system
MM Middle marker
MMMM Connect to... stations (used in multiple transmission, followed by call signs of stations)*
MNH Middle latitudes northern hemisphere
MNM Minimum
MNPS Minimum navigation performance specifications
MNT Monitor or monitoring or monitored
MNTN Maintain
MOA Military operating area
MOC Minimum obstacle clearance (required)
MOCA Minimum obstacle clearance altitude
MOD Moderate (used to qualify icing, turbulence, interference, or static reports)*
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
MOTNE Meteorological Operational Telecommunications Network Europe*
MOV Move or moving or movement
MPH Statute miles per hour*
MPS Metres per second
MRA Minimum reception altitude
MRG Medium range
MRP ATS/MET reporting point
MS Minus
MSA Minimum safe altitude*
MSA Minimum sector altitude
MSAS † Multifunctional transport satellite (MTSAT) satellite-based augmentation system (to be pronounced “EM-SAS”)
MSAW Minimum safe altitude warning
MSG Message
MSH Middle latitudes southern hemisphere
MSL Mean sea level
MSR Message... (transmission identification) has been misrouted (to be used in AFS as a procedure signal)
MSSR Monopulse secondary surveillance radar
MT Mountain
MTOM Maximum take-off mass
MTOW Maximum Take-Off Weight
MTU Metric units
MTW Mountain waves
MVDF Medium and very high frequency direction-finding stations (at the same location)
MWO Meteorological watch office
MX Mixed type of ice formation (white and clear)
N No distinct tendency (in RVR during previous 10 minutes)
N North or northern latitude
NADP Noise abatement departure procedure
NASC † National AIS system centre
NAT North Atlantic
NAV Navigation
NAVAID Navigation aid
NB Northbound
NBFR Not before
NC No change
NCD No cloud detected (used in automated METAR/SPECI)
ND I am unable to deliver message... (filing number) addressed to aircraft... (identification): please notify message originator*
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
NEH I am connecting you to a station which will accept traffic for the station you request*
NGT Night
NIL † None or I have nothing to send to you
NM Nautical miles
NML Normal
NN No name, unnamed
NMOC Network Manager Operations Centre*
NNE North-north-east
NNW North-north-west
NO No (negative) (to be used in AFS as a procedure signal)
NOF International NOTAM office
NONSTD Non-standard
NOSIG † No significant change (used in trend-type landing forecasts)
NOTAM † 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
NPA Non-precision approach
NR Number
NRH No reply heard
NS Nimbostratus
NSC Nil significant cloud
NSE Navigation system error
NSW Nil significant weather
NTL National
NTZ ‡ No transgression zone
NW North-west
NWB North-westbound
NXT Next
OAC Oceanic area control centre
OAS Obstacle assessment surface
OAT  Operational Air Traffic*
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)
OCC The line is engaged*
OCH Obstacle clearance height
OCL Obstacle clearance limit*
OCNL Occasional or occasionally
OCS Obstacle clearance surface
OCT October
OEP Oceanic Entry Point
OFZ Obstacle free zone
OGN Originate (to be used in AFS as a procedure signal)
OHD Overhead
OIS Obstacle identification surface
OK We agree or it is correct (to be used in AFS as a procedure signal)
OLDI † On-line data interchange
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
OTP On top
OTS Organized track system
OUBD Outbound
OVC Overcast
OXP Oceanic Exit Point
P... Maximum value of wind speed or runway visual range (followed by figures in METAR/SPECI and TAF)
P... Prohibited area (followed by identification)
PA Precision approach
PALS Precision approach lighting system (specify category)
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)
PBC Performance-based communication
PBN Performance-based navigation
PBS Performance-based surveillance
PCD Proceed or proceeding
PCL Pilot-controlled lighting
PCN Pavement classification number
PCT Per cent
PDC ‡ Pre-departure clearance
PDG Procedure design gradient
PE Ice pellets*
PER Performance
PERM Permanent
PIB Pre-flight information bulletin
PJE Parachute jumping exercise
PL Ice pellets
PLA Practice low approach
PLVL Present level
PLN Flight plan
PN Prior notice required
PNR Point to 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
PRD Prohibited – Restricted - Danger*
PRKG Parking
PROB † Probability
PROC Procedure
PROP Propeller
PROV Provisional
PRP Point-in-space reference point
PS Plus
PSG Passing
PSGR Passenger*
PSN Position
PSP Pierced steel plank
PSR ‡ Primary surveillance radar
PSYS Pressure system(s)
PTN Procedure turn
PTS Polar track structure
PUN Prepare a new perforated tape for message...*
PWR Power
QBI Compulsory IFR flight*
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)
QJH Shall I run my test tape/a test sentence? or Run your test tape/a test sentence (to be used in AFS as a Q Code)
QNH ‡ Altimeter sub-scale setting to obtain elevation when on the ground
QSP Will you relay to... free of charge? or I will relay to... free of charge (to be used in AFS as a Q Code)
QTA Shall I cancel telegram number...? or Cancel telegram number... (to be used in AFS as a Q Code)
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... at... 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 at... hours (to be used in radiotelegraphy as a Q Code)
R Rate of turn
R Received (acknowledgement of receipt)
R Received (acknowledgement of receipt) (to be used in AFS as a procedure signal)
R Red
R Right (preceded by runway designation number to identify a parallel runway (...R))
R Right (preceded by runway designation number to identify a parallel runway)*
R Romeo*
R... Radial from VOR (followed by three figures)
R... Restricted area (followed by identification)
R... Runway (followed by figures in METAR/SPECI)
RA Rain
RA Resolution advisory
RAC Rules of the air and air traffic services
RAG Ragged 
RAG Runway arresting gear
RAI Runway alignment indicator
RAIM Receiver autonomous integrity monitoring
RAPID Rapid or rapidly*
RASC † Regional AIS system centre
RASH Rain showers
RASN Rain and snow or showers of rain and snow*
RASS Remote altimeter setting source
RB Read back*
RB Rescue boat
RCA Reach cruising altitude
RCC Rescue co-ordination centre
RCF Radio communication failure (message type designator)
RCH Reach or reaching
RCL Runway centre line
RCL Request for Clearance. A Voice, or Data Link message via ACARS, used to provide ETA at OEP, requested Flight Level, and Mach.*
RCLL Runway centre line light(s)
RCLR Recleared
RCP ‡ Required communication performance
RDH Reference datum height
RDH Reference datum height (for ILS)*
RDL Radial
RDO Radio
RDOACT Radioactive
RE Recent (used to qualify weather phenomena, e.g. recent rain = RERA)
REC Receive or receiver
REDL Runway edge light(s)
REF Reference to... or refer to...
REG Registration
RENL Runway end light(s)
REP Report or reporting or reporting point
REQ Request or requested
RERTE Re-route
RESA Runway end safety area
RET Rapid Exit Taxiway*
RF Constant radius arc to a fix
RFFS Rescue and fire fighting services
RG Range (lights)
RHC Right-hand circuit
RIF Reclearance in flight
RIME † Rime (used in aerodrome warnings)
RITE Right (direction of turn)
RL Report leaving
RLA Relay to
RLCE Request level change en route
RLLS Runway lead-in lighting system
RLNA Requested level not available
RMK Remark
RNAV † Area navigation (to be pronounced “AR-NAV”)
RNG Radio range
RNP ‡ Required navigation performance
ROBEX † Regional OPMET bulletin exchange (scheme)
ROC Rate of climb
ROD Rate of descent
ROFOR Route forecast (in aeronautical meteorological code)
RON Receiving only
ROT Runway Occupancy Time*
RPDS Reference path data selector
RPI ‡ Radar position indicator
RPL Repetitive flight plan
RPLC Replace or replaced
RPS Radar position symbol
RPT Repeat or I repeat
RQ Request
RQMNTS Requirements
RQP Request flight plan (message type indicator)
RQS Request supplementary flight plan (message type indicator)
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
RSP ‡ Required surveillance performance
RSR En-route surveillance radar
RSS Root sum square
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
RVA Radar vectoring area
RVR ‡ Runway visual range
RVSM ‡ Reduced vertical separation minimum [300 m (1 000 ft) between FL 290 and FL 410]
RWY Runway
S... State of the sea (followed by figures in METAR/SPECI)
SA Sand
SA Dust-storm, sand-storm, rising dust or rising sand*
SALS Simple approach lighting system
SAN Sanitary
SAP As soon as possible*
SAR Search and rescue
SARPS Standards and Recommended Practices (ICAO)
SAT Saturday
SATCOM † Satellite communication (used only when referring generally to both voice and data satellite communication or only data satellite communication)
SATVOICE † Satellite voice communication
SB South bound
SBAS † Satellite-based augmentation system (to be pronounced “ESS-BAS”)
SC Stratocumulus
SCT Scattered
SDBY Stand by
SDF Step down fix
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)
SI International system of units
SID † Standard instrument departure
SIF Selective identification feature
SIG Significant
SIGMET † Information concerning en-route weather and other phenomena in the atmosphere that may affect the safety of aircraft operations
SIGWX Significant weather*
SIMUL Simultaneous or simultaneously
SIWL Single isolated wheel load
SKC Sky clear*
SKED Schedule or scheduled
SLOP Strategic Lateral Offset Procedure*
SLW Slow
SMC Surface movement control
SMR Surface movement radar
SN Snow
SNOWTAM † A special series NOTAM given in a standard format providing a surface condition report notifying the presence or cessation of hazardous conditions due to snow, ice, slush, frost, standing water or water associated with snow, slush, ice or frost on the movement area
SNSH Snow showers*
SOC Start of climb
SPECI † Aerodrome special meteorological report (in meteorological code)
SPECIAL † Local special meteorological report (in abbreviated plain language)
SPI Special position indicator
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
SSB Single sideband
SSE South-south-east
SSR ‡ Secondary surveillance radar
SST Supersonic transport
SSW South-south-west
ST Stratus
STA Straight-in approach
STAR † Standard instrument arrival
STD Standard
STF Stratiform
STN Station
STNR Stationary
STOL Short take-off and landing
STS Status
STWL Stopway light(s)
SUBJ Subject to
SUN Sunday
SUP Supplement (AIP supplement)
SUPPS Regional supplementary procedures
SVC Service (message type only)
SVCBL Serviceable
SW South-west
SWB South-westbound
SWC Significant Weather Chart*
SWX Space weather
SWXC Space weather centre
SWY Stopway
T Temperature
T True (preceded by a bearing to indicate reference to True North (...T))
TA Traffic advisory
TA Transition altitude
TA/H Turn at an altitude/height
TAA Terminal Arrival Altitude
TACAN † UHF tactical air navigation aid
TAF † Aerodrome forecast (in meteorological code)
TAIL † Tail wind
TAR Terminal area surveillance radar
TAS True airspeed
TAX Taxiing or taxi
TC Tropical cyclone
TCAC Tropical cyclone advisory centre
TCAS RA † Traffic alert and collision avoidance system resolution advisory (to be pronounced “TEE-CAS-AR-AY”)
TCH Threshold Crossing Height
TCU Towering cumulus
TDO Tornado
TDZ Touchdown zone
TECR Technical reason
TEL Telephone
TEMPO † Temporary or temporarily
TEND Trend or tending to*
TF Track to fix
TFC Traffic
TGL Touch-and-go landing
TGS Taxiing guidance system
THR Threshold
THRU Through
THU Thursday
TIBA † Traffic information broadcast by aircraft
TIL † Until
TIP... Until past (followed by place)
TIZ Traffic information zone*
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 TAF)
TNA Turn altitude
TNC Terminal Navigation Charge*
TNH Turn height
TO... To (followed by place)
TOC Top of climb
TODA Take-off distance available
TODAH Take-off distance available, helicopter
TOP † Cloud top
TORA Take-off run available
TOX Toxic
TP Turning point
TR Track
TRA Temporary Reserved Area
TRANS Transmits or transmitter
TREND † Trend forecast
TRG Training
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)
TSA Temporary Segregated Area*
TSGR Thunderstorm with hail*
TSSA Thunderstorm with duststorm or sandstorm*
TSUNAMI † Tsunami (used in aerodrome warnings)
TT Teletype-writer
TUE Tuesday
TURB Turbulence
T-VASIS † T visual approach slope indicator system (to be pronounced “TEE-VASIS”)
TVOR Terminal VOR
TWIL Twilight*
TWR Aerodrome control tower or aerodrome control
TWY Taxiway
TWYL Taxiway-link*
TX... Maximum temperature (followed by figures in TAF)
TXL Taxilane
TXT Text (when the abbreviation is used to request a repetition, the question mark (IMI) precedes the abbreviation, e.g. IMI TXT) (to be used in AFS as a procedure signal)
TYP Type of aircraft
TYPH Typhoon
U Upward (tendency in RVR during previous 10 minutes)
UA Unmanned aircraft
UAB Until advised by...
UAC Upper area control centre
UAR Upper air route
UAS Unmanned aircraft system
UDF Ultra high frequency direction-finding station
UFN Until further notice
UHDT Unable higher due traffic
UHF ‡ Ultra high frequency (300 to 3000 MHz)
UIC Upper information centre
UIR ‡ Upper flight information region
ULM Ultra light motorized aircraft
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
V Variations from the mean wind direction (preceded and followed by figures in METAR/SPECI (...V...), e.g. 350V070)
VA Heading to an altitude
VA Volcanic ash
VAAC Volcanic ash advisory centre
VAC... Visual approach chart (followed by name/title)
VAL In valleys
VAL Visual approach and landing chart*
VAN Runway control van
VAR Magnetic variation
VAR Visual-aural radio range
VASIS Visual approach slope indicator system
VC... Vicinity of the aerodrome (followed by FG = fog, FC = funnel cloud, SH = shower, PO = dust/sand whirls, BLDU = blowing dust, BLSA = blowing sand, BLSN = blowing snow, DS = duststorm, SS = sandstorm, TS = thunderstorm or VA = volcanic ash, e.g. VCFG = vicinity fog)
VCY Vicinity
VDF Very high frequency direction-finding station
VER Vertical
VFR ‡ Visual flight rules
VHF ‡ Very high frequency (30 to 300 MHz)
VI  Heading to an intercept
VIA By way of...*
VIO Heavy (used to qualify interference or static reports)*
VIP ‡ Very important person
VIS Visibility
VLF Very low frequency (3 to 30 kHz)
VLR Very long range
VM Heading to a manual termination
VMC ‡ Visual meteorological conditions
VNAV † Vertical navigation (to be pronounced “VEE-NAV”)
VOL... Volume (followed by I, II...)
VOLMET † Meteorological information for aircraft in flight
VOR ‡ VHF omnidirectional radio range
VORTAC † VOR and TACAN combination
VOT VOR airborne equipment test facility
VPA Vertical path angle
VPT Visual manoeuvre with prescribed track
VRB Variable
VSA By visual reference to the ground
VSP Vertical speed
VTF Vector to final
VTOL Vertical take-off and landing
VV... Vertical visibility (followed by figures in METAR/SPECI and TAF)
VVV Retransmit this message to all addressees mentioned in the line-following-the-heading, as though it had been filed locally at your centre (group used in a diversion indicator)*
VVV..VVV Marking or test transmission (sent in a series)*
W West or western longitude
W White
W... Sea-surface temperature (followed by figures in METAR/SPECI)
WA Word after... *
WAAS † Wide area augmentation system
WAC... World Aeronautical Chart - ICAO 1:1 000 000 (followed by name/title)
WAFC World area forecast centre
WAFS World area forecast system*
WB Westbound
WBAR Wing bar lights
WD Words or groups*
WDI Wind direction indicator
WDSPR Widespread
WED Wednesday
WEF With effect from or effective from
WGS-84 World Geodetic System — 1984
WHI White*
WI Within
WID Width or wide
WIE With immediate effect or effective immediately
WILCO † Will comply
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
WXR Weather radar
X Cross
XBAR Crossbar (of approach lighting system)
XNG Crossing
XS Atmospherics
XX Heavy (used to qualify weather phenomena such as rain, e.g. heavy rain = XXRA)*

Y Yellow
YCZ Yellow caution zone (runway lighting)
YD Yards*
YES Yes (affirmative) (to be used in AFS as a procedure signal)
YR Your

Z Coordinated Universal Time (in meteorological messages)