Amber

(or AAB, AAC ... etc, in sequence) amended meteorological message (message type designator)

Air-to-air

Assigned altitude deviation

Aircraft autonomous integrity monitoring

Above aerodrome level

Advance boundary information

Abeam

Aerodrome beacon

About

Above

Altocumulus

Aircraft communication addressing and reporting system (to be pronounced "AY-CARS")

Airborne collision avoidance system

Area control centre or area control

Notification of an aircraft accident

Aircraft

Acknowledge

Altimeter check location

Aircraft classification number

Acceptance (message type designator)

Accept or accepted

Active or activated or activity

Aerodrome

Advisory area

Aerodrome chart

Addition or additional

Automatic direction-finding equipment

Air defence identification zone (to be pronounced "AY-DIZ")

Adjacent

Aerodrome office (specify service)

Advisory route

The 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)

Automatic dependent surveillance - broadcast

Automatic dependent surveillance - contract

Automatic dependent surveillance unit

Advisory service

Advise

Aircraft earth station

Flight plan filed in the air

Aerodrome flight information service

Yes or affirm or affirmative or that is correct

Aeronautical fixed service

After ... (time or place)

Aeronautical fixed telecommunication network

Air-to-ground

Aerodrome, air routes and ground aids

Above ground level

Again

Aeronautical information circular

Air traffic services inter-facility data communication

Aeronautical information publication

Aeronautical information regulation and control

Air-report

Information concerning en-route weather phenomena which may affect the safety of low-level aircraft operations

Aeronautical information services

Alighting area

Alert phase

Alerting (message type designator)

Alerting service

Approach lighting system

Altitude

Alternate or alternating (light alternates in colour)

Alternate (aerodrome)

Area minimum altitude

Amend or amended (used to indicate amended meteorological message; message type designator)

Amendment (AIP amendment)

Aeronautical mobile service

Above mean sea level

Aeronautical mobile satellite service

Aeronautical chart - 1:500 000 (followed by name/title)

Aeronautical navigation chart - small scale (followed by name/title)

Answer

Aerodrome obstacle chart (followed by name/title)

Airport

Abbreviated precision approach path indicator (to be pronounced "AY-PAPI")

Approach

Aircraft parking/docking chart (followed by name/title)

Apron

Approach control office or approach control or approach control service

April

Approximate or approximately

After passing

Approve or approved or approval

Area chart

Arrange

Air traffic services reporting office

Aerodrome reference point

Air-report (message type designator)

Automatic error correction

Arrival (message type designator)

Arrive or arrival

Special air-report

Arresting [specify (part of) aircraft arresting equipment]

Altostratus

Ascent to or ascending to

Accelerate-stop distance available

Altimetry system error

Airspeed gain

Airspeed loss

Asphalt

A special series NOTAM notifying by means of a specific format change in activity of a volcano, a volcano eruption and/or volcanic ash cloud that is of significance to aircraft operations.

At ... (followed by time at which weather change is forecast to occur)

Actual time of arrival

Air traffic control (in general)

Air traffic control surveillance minimum altitude chart (followed by name/title)

Actual time of departure

Air traffic flow management

Automatic terminal information service

Air traffic management

Aeronautical telecommunication network

At ... (time or place)

Air traffic services

Attention

Abbreviated T visual approach slope indicator system (to be pronounced "AY-TEE-VASIS")

Aerodrome traffic zone

August

Authorised or authorisation

All up weight

Auxiliary

Available or availability

Average

Aviation gasoline

Advise at what time able

Airway

Azimuth

Blue

Braking action

(to be pronounced "BAA-RO-VEENAV") Barometric vertical navigation

Cloud base

Fog patches

Beacon (aeronautical ground light)

Broadcast

Boundary

Becoming

Before

Broken

Blowing (followed by DU= dust, SA= sand or SN= snow)

Building

Below clouds

Below

Bombing

Mist

Short (used to indicate the type of approach desired or required)

Bearing

Braking

Commercial broadcasting station

Between layers

Between

Centre (proceeded by runway designation number to identify a parallel runway)

Degrees Celsius (Centigrade)

Course to an altitude

Category

Clear air turbulence

Visibility, cloud and present weather better than prescribed values or conditions (to be pronounced "KAV-OH-KAY")

Cumulonimbus (to be pronounced "CEE BEE")

Cirrocumulus

(or CCB, CCC ...etc, in sequence) Corrected meteorological message (message type designator)

Candela

Co-ordination (message type designator)

Change frequency to ...

Course to a fix

Confirm or I confirm (to be used in AFS as a procedure signal)

Circling guidance light(s)

Channel

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)

Modification (message type designator)

Cirrus

Common ICAO data interchange network

Near or over large towns

Civil

Check

Centre line

Clear type of ice formation

Calibration

Cloud

Calling

Climb-out area

Clear(s) or cleared to ... or clearance

Runway(s) cleared (used in METAR/SPECI)

Close or closed or closing

Centimetre

Climb to or climbing to

Completion or completed or complete

Cancel or cancelled

Flight plan cancellation message (message type designator)

Communications, navigation and surveillance

Communications

Concrete

Condition

Continuous

Construction or constructed

Continue(s) or continued

Co-ordinate or coordination

Coordinates

Change-over point

Correct or corrected or correction (message type designator)

At the coast

Cover or covered or covering

Controller-pilot data link communications

Current flight plan (message type designator)

Cyclic redundancy check

Cruise

Call sign

Cirrostratus

Control area

Climb to and maintain

Contact ...

Control

Caution

Control zone

Cumulus

Cumuliform

Customs

Cockpit voice recorder

Continuous wave

Clearway

Downward (tendency in RVR during previous 10 minutes)

Danger area (followed by identification)

Decision altitude

Data link automatic terminal information service (to be pronounced "DEE-ATIS")

Double channel duplex

Docking

Datum crossing point

Direct controller-pilot communications

Double channel simplex

Direct (in relation to flight plan clearances and type of approach)

From (used to precede the call sign of the calling station) (to be used in AFS as a procedure signal)

December

Degrees

Depart or departure

Departure (message type designator)

Departure end of the runway

Descend to or descending to

Destination

Distress phase

Deviation or deviating

Direction finding

Digital flight data recorder

Distance from touchdown indicator

Decision height

Diffuse

Distance

Divert or diverting

Delay or delayed

Delay (message type designator)

Data link initiation capability

Daily

Distance measuring equipment

Danger or dangerous

Domestic

Dew point temperature

Depth

Dead reckoning

Low drifting (followed by DU= dust, SA= sand or SN = snow)

During

Duststorm

Double sideband

Descend to and maintain

Date-time group

Displaced runway threshold

Deteriorate or deteriorating

Dual tandem wheels

Dust

Dense upper cloud

This is a duplicate message (to be used in AFS as a procedure signal)

Duration

Data link VOLMET

Doppler VOR

Dual wheels

Drizzle

East or eastern longitude

Expected approach time

Eastbound

Elevation differential area

Error (to be used in AFS as a procedure signal)

Estimated elapsed time

Expect further clearance

Electronic flight instrument system (to be pronounced "EE-FIS")

European geostationary navigation overlay service (to be pronounced "EGG-NOS")

Extremely high frequency [30 000 to 300 000 MHz]

Emergency location beacon - Aircraft

Elevation

Extra-long range

Emergency locator transmitter

Emission

Embedded in a layer (to indicate cumulonimbus embedded in layers of other clouds)

Emergency

Stop-end (related to RVR)

East-north-east

Engine

En-route (followed by name/title)

En-route chart (followed by name/title)

Estimated off-block time

Equipment

Here ... or here with

East-south-east

Estimate or estimated or estimation (message type designator)

Estimated time of arrival or estimating arrival

Estimated time of departure or estimating departure

Estimated time over significant point

Every

Except

Exercises or exercising or to exercise

Expect or expected or expecting

Extend or extending

Fixed

Course from a fix to an altitude

Facilities

Final approach fix

Facilitation of international air transport

Final approach point

Final approach segment

Final approach and take-off area

Facsimile transmission

Light (used to indicate the intensity of weather phenomena, interference or static reports, e.g. FBL RA = light rain)

Funnel cloud (tornado or water spout)

Forecast

Friction coefficient

Flight data processing system

February

Few

Fog

Flight information centre

Flight information region

Flight information service

Automated flight information service

Flight level

Field

Flashing

Flares

Flight

Flight check

Fluctuating or fluctuation or fluctuated

Follow(s) or following

Fly or flying

From

From (followed by time weather change is forecast to begin)

Flight management computer

Flight management system

Flow management unit

Final approach

Flight path alignment point

Filed flight plan (message type designator)

Feet per minute

Flight plan route

Fuel remaining

Frequency

Friday

Firing

Front (relating to weather)

Frost (used in aerodrome warnings)

Frequent

Full stop landing

Flight service station

First

Feet (dimensional unit)

Flight technical error

Fictitious threshold point

Flight technical tolerance

Smoke

Freezing

Freezing drizzle

Freezing fog

Freezing rain

Green

Variations from the mean wind speed (gust) (followed by figures in METAR/SPECI/TAF)

Go ahead, resume sending (to be used in AFS as a procedure signal)

Ground-to-air

Ground-to-air and air-to-ground

GPS and geostationary earth orbit augmented navigation

Area forecast for low-level flights

GBAS azimuth reference point

Ground-based augmentation system (to be pronounced "GEE-BAS")

Ground controlled approach system or ground controlled approach

General

Geographic or true

Ground earth station

Glider

Global orbiting navigation satellite system (to be pronounced "GLO-NAS")

GBAS landing system

Ground movement chart (followed by name/title)

Ground

Ground check

Global navigation satellite system

Glide path

Glide path angle

Glide path intercept point

Global positioning system

Ground proximity warning system

Hail

Ground-based regional augmentation system (to be pronounced "GRASS")

Grass landing area

Processed meteorological data in the form of grid points values expressed in binary form (meteorological code)

Gravel

Ground speed

Small hail and/or snow pellets

Geoid undulation

High pressure area or the centre of high pressure

Continuous day and night service

Holding/racetrack to an altitude

Helicopter approach path indicator

Hazard beacon

High frequency direction finding station

Heading

Helicopter

High frequency [3 000 to 30 000 KHz]

Height or height above

Sunrise to sunset

Holding

Holding/racetrack to a manual termination

Sunset to sunrise

Service available to meet operational requirements

Holiday

Hospital aircraft

Hectopascal

Hours

Service available during hours of scheduled operations

Hurricane

High and very high frequency direction-finding stations (at the same location)

Heavy

Heavy (used to indicate the intensity of weather phenomena, e.g. HVY RA = heavy rain)

No specific working hours

Higher

Haze

Hertz (cycle per second)

Instrument approach chart (followed by name/title)

Initial approach fix

In and out of clouds

Instrument approach procedure

Intersection of air route

Indicated of air speed

Identification beacon

Diamond dust (very small ice crystals in suspension, also known as diamond dust)

Icing

Identifier or identify

Identification

Intermediate approach fix

Identification friend/foe

Instrument flight rules

International general aviation

Instrument landing system

Inner marker

Instrument meteorological conditions

Immigration

Interogation sign (question mark) (to be used in AFS as a procedure signal)

Improve or improving

Immediate or immediately

Initial approach

Inbound

In cloud

Uncertainty phase

Information

Inoperative

If not possible

In progress

Inertial navigation system

Install or installed or installation

Instrument

Intersection

International

Interrogator

Interrupt or interruption or interrupted

Intensify or intensifying

Intensity

Ice on runway

Inertial reference system

International standard atmosphere

Independent sideband

Isolated

January

Jet stream

July

June

Kilograms

Kilohertz

Knots indicated airspeed

Kilometres

Kilometres per hour

Kilopascal

Knots

Kilowatts

Left (proceeded by runway designation number to identify a parallel runway)

Locator (see LM, LO)

Low pressure area or the centre of low pressure

Logical acknowledgement (message type designator)

Inland

Latitude

Local or locally or location or located

Landing distance available

Landing distance available, helicopter

Landing

Landing direction indicator

Length

Low frequency [30 to 300 KHz]

Light or lighting

Lighted

Light intensity high

Light intensity low

Light intensity medium

Line (used in SIGMET)

Localizer

Locator middle

Local mean time

Lateral navigation (to be pronounced "EL-NAV")

Long (used to indicate the type of approach desired or required)

Locator, outer

Localizer

Longitude

Long range air navigation system

Localizer performance with vertical guidance

The last message received by me was ... (to be used in AFS as a procedure signal)

Long range

The last message sent by me was ... or Last message was ... (to be used in AFS as a procedure signal)

Limited

Landing threshold point

Landline teletypewriter

Light and variable (relating to wind)

Leave or leaving

Level

Low visibility procedures

Layer or layered

Mach number (followed by figures)

Metres (preceded by figures)

Maximum authorized altitude

Magnetic

Missed approach holding fix

Maintenance

Aeronautical maps and charts

Missed approach point

At sea

March

Manual A1 simplex

Missed approach turning fix

Maximum

May

Microburst

Minimum crossing altitude

Modulated continuous wave

Minimum descent altitude

Medium frequency direction finding station

Minimum descent height

Minimum en-route altitude

Minimum eye height over threshold (for visual approach slope indicator systems)

Meteorological or meteorology

Aerodrome routine meteorological report (in meteorological code)

Local routine meteorological report (in abbreviated plain language)

Medium frequency [300 to 3 000 KHz]

Medium and high frequency direction finding-stations (at the same location)

Medium, high and very high frequency direction-finding stations (at the same location)

Megahertz

Mid-point (related to RVR)

Shallow fog

Military

Minutes

Missing ... (transmission identification) (to be used in AFS as a procedure signal)

Marker radio beacon

Microwave landing system

Middle Marker

Minimum

Minimum navigation performance specifications

Monitor or monitoring or monitored

Maintain

Military operating area

Minimum obstacle clearance (required)

Minimum obstacle clearance altitude

Moderate (used to indicate the intensity of weather phenomena, interference or static reports e.g. MODRA = moderate rain)

Above mountains

Monday

Minimum opreational performance standards

Meteorological Operational Telecommunications Network Europe

Move or moving or movement

Metres per second

Minimum reception altitude

Medium range

ATS/MET reporting point

Minus

Minimum sector altitude

Multifunctional transport satellite (MTSAT) satellite-based augmentation system (to be pronounced "EM-SAS")

Minimum safe altitude warning

Message

Mean sea level

Message... (transmission identification) has been misrouted (to be used in AFS as a procedure signal)

Mono pulse secondary surveillance radar

Mountain

Metric units

Mountain waves

Medium and very high frequency direction-finding station (at the same location)

Meteorological watch office

Mixed type of ice formation (white and clear)

No distinct tendency (in RVR during previous 10 minutes)

North or northern latitude

Noise abatement departure procedure

National AIS system centre

North Atlantic

Navigation

Northbound

Not before

No change

No cloud detected (used in automated METAR/SPECI)

Non-directional radio beacon

No directional variations available (used in automated METAR/SPECI)

North-east

North-eastbound

No or negative or permission not granted or that is not correct

Night

None or I have nothing to send to you

Nautical miles

Normal

North-north-east

North-north-west

No (negative) (to be used in AFS as a procedure signal)

International NOTAM office

No significant change (used in trend-type landing forecasts)

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.

November

Normal operating zone

Non-precision approach

Number

No reply heard

Nimbostratus

Nil significant cloud

Navigation system error

Nil significant weather

National

No transgression zone

Not usable

North-west

North-westbound

Next

Oceanic area control centre

Obstacle assessment surface

Observe or observed

Obscure or obscured or obscuring

Obstacle

Obstacle clearance altitude

Oceanic control area

Occulting (light)

Obstacle clearance height

Occasional or occasionally

Obstacle clearance surface

October

Overhead

We agree or It is correct (to be used in AFS as a procedure signal)

On-line data interchange

Outer marker

Opaque, white type of ice formation

Control indicated is operational control

Operational meteorological (information)

Open or opening or opened

Operator or operate or operative or operating or operational

Operations

On request

Order

Ocean station vessel

Outlook (used in SIGMET message for volcanic ash and tropical cyclones)

On top

Organized track system

Outbound

Overcast

Maximum value of wind speed on runway visual range (followed by figures in METAR/SPECI and TAF)

Prohibited area (followed by identification)

Precision approach

Precision approach lighting system

Procedures for air navigation services

Precision approach path indicator

Precision approach radar

Parallel

Precision approach terrain chart (followed by name/title)

Passenger(s)

Performance-based navigation

Proceed or proceeding

Pilot-controlled lighting

Pavement classification number

Pre-departure clearance

Procedure design gradient

Performance

Permanent

Pre-flight information bulletin

Parachute jumping exercise

Ice pellets

Practice low approach

Flight plan

Present level

Prior notice required

Point of no return

Dust/sand whirls

Persons on board

Possible

Plan position indicator

Prior permission required

Present position

Aerodrome partially covered by fog

Primary

Parking

Probability

Procedure

Provisional

Plus

Passing

Position

Pierced steel plank

Primary surveillance radar

Pressure system(s)

Procedure turn

Polar track structure

Power

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)

Magnetic heading (Zero wind)

Magnetic bearing

Atmospheric pressure at Aerodrome elevation (or at runway threshold)

Magnetic orientation of runway

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)

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)

Altimeter sub-scale setting to obtain elevation when on the ground

Will you relay to ... free of charge? or I will relay to ... free of charge (to be used in AFS as a Q code)

Shall I cancel telegram number...? or Cancel telegram number... (to be used in AFS as a Q code)

True bearing

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 station that I control was ... latitude ... longitude (or other indication of position, class ... at ... hours)(to be used in radiotelegraphy as a Q code)

Quadrant

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)

Right (preceded by runway designation number to identify a parallel runway)

Red

Rate of turn

Received (acknowledgement of receipt) (to be used in AFS as a procedure signal)

Restricted area (followed by identification)

Runway (followed by figures in METAR/SPECI)

Rain

Resolution advisory

Rules of the air and air traffic services

Ragged

Runway arresting gear

Runway alignment indicator

Receiver autonomous integrity monitoring

Regional AIS system centre

Remote altimeter setting source

Rescue boat

Reach cruising altitude

Rescue co-ordination centre

Radiocommunication failure (message type designator)

Reach or reaching

Runway centre line

Runway centre line light(s)

Recleared

Required communication performance

Reference datum height (for ILS)

Radial

Radio

Recent (used to qualify weather phenomena such as rain e.g. RERA = recent rain)

Receive or receiver

Runway edge light(s)

Reference to ... or refer to ...

Registration

Runway end light(s)

Report or reporting or reporting point

Request or requested

Re-route

Runway end safety area

Constant radius arc to a fix

Range (lights)

Right-hand circuit

Reclearance in flight

Rime (used in aerodrome warnings)

Right (direction of turn)

Report leaving

Relay to

Request level change en-route

Runway lead-in lighting system

Requested level not available

Remark

Area navigation (to be pronounced "AR-NAV")

Radio range

Required navigation performance

Regional OPMET bulletin exchange (scheme)

Rate of climb

Rate of descent

Route forecast (in aeronautical meteorological code)

Receiving only

Reference path data selector

Radar position indicator

Repetitive flight plan

Replace or replaced

Radar position symbol

Repeat or I repeat (to be used in AFS as a procedure signal)

Request (to be used in AFS as a procedure signal)

Requirements

Request flight plan (message type designator)

Request supplementary flight plan (message type designator)

Report reaching

(or RRB, RRC....etc in sequence)Delayed meteorological message (message type designator)

Rescue Sub-centre

Runway surface condition

Responder beacon

En-route surveillance radar

Root sum square

Delayed (used to indicate delayed meteorological message; message type designator)

Route

Radio telephone

Radio telegraph

Runway threshold light(s)

Return or returned or returning

Return to service

Radio teletypewriter

Runway touchdown zone light(s)

Standard regional route transmitting frequencies

Rescue vessel

Runway visual range

Reduced vertical separation minumum (300 m (1 000ft)) between FL 290 and FL 410

Runway

State of the sea (followed by figures in METAR/SPECI)

South or southern latitude

Dust storm, sand storm, rising dust or rising sand

Simple approach lighting system

Sanitary

As soon as possible

Search and rescue

Standards and recommended practices [ICAO]

Saturday

Satellite communication

Southbound

Satellite-based augmentation system (to be pronounced "ESS-BAS")

Stratocumulus

Scattered

Standard deviation

Stand by

Step down fix

South-east

Sea (used in connection with sea-surface temperature and state of the sea)

South-eastbound

Seconds

Section

Sector

Selective calling system

September

Service or servicing or served

Severe (used e.g. to qualify icing and turbulence reports)

Surface

Snow grains

Signal

Showers (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)

Super high frequency [3 000 to 30 000 MHz]

International system of units

Standard instrument departure

Selective identification feature

Significant

Information concerning en-route weather phenomena which may affect the safety of aircraft operations

Simultaneous or simultaneously

Single isolated wheel load

Sky clear

Schedule or scheduled

Speed limiting point

Slow

Surface movement control

Surface movement radar

Snow

Aerodrome closed due to snow (used in METAR/ SPECI)

A special series NOTAM given in a standard format, which provides a surface condition report notifying the presence or cessationremoval of hazardous conditions due to snow, ice, slush, frost, standing water or standing water associated with snow, slush, ice orand frostice on the movement area , by means of a specific format.

Start of climb

Aviation selected special weather report (in aeronautical meteorological code)

Special meteorological weather report (in abbreviated plain language)

Special position indicator

Supplementary flight plan (message type designator)

SAR point of contact

Spot wind

Squall

Squall line

Sunrise

Surveillance radar approach

Surveillance radar element of precision approach radar system

Short range

Search and rescue region

Secondary

Sunset

Sandstorm

Single sideband

South-south-east

Secondary surveillance radar

Supersonic transport

South-south-west

Stratus

Straight-in approach

Standard instrument arrival

Standard

Stratiform

Station

Stationary

Short take-off and landing

Status

Stopway light(s)

Subject to

Sunday

Supplement (AIP supplement)

Regional supplementary procedures

Service message

Serviceable

South-west

South-westbound

Stopway

Temperature

True (preceded by a bearing to indicate reference to True North)

Transition altitude

Traffic advisory

Terminal arrival altitude

UHF tactical air navigation aid

Aerodrome forecast

Turn at an altitude/height

Tail wind

Terminal area surveillance radar

True airspeed

Taxiing or taxi

Tropical cyclone

Tropical cyclone advisory centre

Traffic alert and collision avoidance system resolution advisory (to be pronounced "TEE-CAS-AR-AY")

Threshold crossing height

Towering cumulus

Tornado

Touchdown zone

Technical reason

Telephone

Temporary or temporarily

Traffic

Touch-and-go landing

Taxiing guidance system

Threshold

Through

Thursday

Traffic information broadcast by aircraft

Until

Until past ... (place)

Take-off

Till (followed by time by which weather change is forecast to end)

Touchdown and lift-off area

Terminal control area

Minimum temperature (followed by figures in TAF)

Turn altitude

Turn height

To ... (place)

Top of climb

Take-off distance available

Take-off distance available, helicopter

Cloud top

Take-off run available

Turning point

Track

Temporary reserved airspace

Transmits or transmitter

Trend forecast

Transition level

Tropopause

Thunderstorm (in aerodrome reports and forecasts, TS used alone means thunder heard but no precipitation at the aerodrome)

Thunderstorm (followed by RA = RAIN, SN = snow, PL= ice pellets, GR = hail, GS = small hail and/ or snow pellets of combinations thereof, e.g. TSRASN = thunderstorm with rain and snow)

Teletypewriter

Tuesday

Turbulence

T visual approach slope indicator system (to be pronounced "TEE-VASIS")

Terminal VOR

Aerodrome control tower or aerodrome control

Taxiway

Taxiway-link

Maximum temperature (followed by figures in TAF)

Text (when the abbreviation is used to request a repitition, the question mark (IMI) precedes the abbreviation, e.g. IMI TXT) (to be used in AFS as a procedure signal)

Type of aircraft

Typhoon

Upward (10 tendency in RVR during previous 10 minutes)

Until advised by ...

Upper area control centre

Upper air route

Ultra high frequency direction-finding station

Until further notice

Unable higher due traffic

Ultra high frequency [300 to 3 000 MHz]

Upper information centre

Upper flight information region

Ultra long range

Unable

Unable to approve

Unlimited

Unreliable

Unidentified precipitation (used in automated METAR/ SPECI)

Unserviceable

Upper control area

Coordinated universal time

Variations from the mean wind direction (preceded and followed by fingers in METAR/ SPECI, e.g. 350V070)

Volcanic ash

Volcanic ash advisory centre

Visual approach chart (followed by name/tilte)

In valleys

Runway control van

Magnetic variation

Visual-aural radio range

Visual approach slope indicator system

Vicinity of the aerodrome (followed by FG = fog, FC=funnel cloud, SH = showers, PO = dust/sand whirls, BLDU = blowing dust, BLSA = blowing sand or BLSN = blowing snow, e.g. VCFG = vicinity fog)

Vicinity

Very high frequency direction-finding station

Vertical

Visual flight rules

Very high frequency [30 to 300 MHz]

Very important person

Visibility

Very low frequency [3 to 30 KHz]

Very long range

Visual meteorological conditions

Meteorological information for aircraft in flight

VHF omnidirectional radio range

VOR and TACAN combination

VOR airborne equipment test facility

Verrtical path angle

Variable

By visual reference to the ground

Vertical speed

Vertical take-off and landing

Vertical visibility (followed by figures in METAR/ SPECI and TAF)

West or western longitude

White

Sea surface temperature (followed by figures in METAR/ SPECI)

Wide area augmentation system

World aeronautical chart-ICAO 1:1 000 000

World area forecast centre

Westbound

Wing bar lights

Wind direction indicator

Widespread

Wednesday

With effect from or effective from

World Geodetic System - 1984

Within

Width

With immediate effect or effective immediately

Will comply

Wind

Forecast upper wind and temperature for aviation

Work in progress

Weaken or weakening

West-north-west

Without

Way-point

Warning

Wind shear

Wind speed

West-south-west

Weight

Waterspout

Worldwide web

Weather

Cross

Crossbar (of approach lighting system)

Crossing

Atmospherics

Yellow

Yellow caution zone (runway lighting)

Yes (affirmative) (to be used in AFS as a procedure signal)

Your

Co-ordinated Universal Time (in meteorological messages)