TRULES_PROC;RULES_PROC_ID;661

- A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
	Terms which are not defined in ICAO Annexes or PANS but which are used regularly in the UK are defined below:
. - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
...T	True (preceded by a bearing to indicate reference to True North)
A - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A/A	Air-to-air
A/G	Air-to-Ground
AAA	(or AAB, AAC....etc, in sequence) Amended meteorological message (message type designator)
AAL	Above Aerodrome Level
AAR	Air to Air Refuelling
AARA	Air to Air Refuelling Areas
ABM	Abeam
ABN	Aerodrome Beacon
ABV	Above
AC	Area Control
ACARS	Aircraft Communications Addressing And Reporting System
ACAS	†Airborne Collision Avoidance Systems
ACC	‡Area Control Centre OR Area Control
ACCID	Notification of an Aircraft Accident
ACFT	Aircraft
ACK	Acknowledge
ACL	Altimeter Check Location
ACN	Airspace Co-ordination Notice (ACN in ICAO is aircraft classification number)
ACT	Active OR Activated OR Activity
AD	Aerodrome
ADA	Advisory Area
ADF	‡Automatic Direction-Finding Equipment
ADIZ	†(to be pronounced 'AY-DIZ') Air Defence Identification Code
ADS-B	‡Automatic Dependent Surveillance - Broadcast
ADS-C	‡Automatic Dependent Surveillance - Contract
ADSU	Automatic Dependent Surveillance Unit
ADVS	Advisory Service
Aerodrome Approach:	That part of an Instrument Approach Procedure commencing at the designated height over the radio aid to be used and ending when the aircraft has broken cloud.
AEW	Airborne Early Warning
AFIL	Flight Plan Filed in the Air
AFIS	Aerodrome Flight Information Service
AFPEx	Assisted Flight Plan Exchange
AFS	Aeronautical Fixed Service
AFTN	‡Aeronautical Fixed Telecommunication Network
AGL	Above Ground Level
AGNIS	Azimuth Guidance for Nose-In Stand
AIAA	Area of Intense Air Activity
AIC	Aeronautical Information Circular
AIM	Aeronautical Information Management
AIP	Aeronautical Information Publication
AIRAC	Aeronautical Information Regulation and Control
AIREP	†Air-Report
AIREX	Air Exercise
AIRPROX:	A situation in which, in the opinion of a pilot or a controller, the distance between aircraft as well as their relative positions and speed have been such that the safety of the aircraft involved was or may have been comprised.
AIS	Aeronautical Information Services
ALA	Alighting Area
ALERFA	†Alert Phase
ALR	Alerting (message type designator)
ALRS	Alerting Service
ALS	Approach Lighting System
ALT	Altitude
ALTN	Alternate (Aerodrome)
AMA	Area Minimum Altitude
AMC	Airspace Management Cell
AMD	Amend OR Amended (used to indicate amended meteorological message; message type designator)
AMDT	Amendment (AIP Amendment)
AMS	Aeronautical Mobile Service
AMSL	Above Mean Sea Level
AMSS	Aeronautical Mobile Satellite Service
ANM	ATFM Notification Message
ANO	Air Navigation Order
AO	Aircraft Operators
AOC	Air Operator Certificate
AOM	Aerodrome Operating Minima
AP	Airport
APAPI	Abbreviated Precision Approach Path Indicator
APCH	Approach
APIS	Aircraft Positioning and Information System
APP	Approach Control Office OR Approach Control OR Approach Control Service
APRX	Approximate OR Approximately
ARA	Advisory Radio Area
ARO	Air Traffic Services Reporting Office
ARP	Air-Report (message type designator)
ARR	Arrival (message type designator)
ARST	Arresting (Specify (part of ) Aircraft Arresting Equipment)
ASC	Ascent to OR Ascending to
ASDA	Accelerate-Stop Distance Available
ASHTAM	Special series of NOTAM notifying, by means of specific format, change in activity of a volcano, a volcano eruption and/or volcanic ash cloud that is of significance to aircraft operations
ASPH	Asphalt
ASR	Airspace Reservation
ATA	Aerial Tactics Area
ATC	‡Air Traffic Control (in general)
ATC Surveillance Minimum Altitude Area:	A defined area in the vicinity of an aerodrome, in which the minimum safe levels allocated by a controller vectoring IFR flights with Primary and/or Secondary Radar equipment have been predetermined.
ATD	‡Actual Time of Departure
ATFM	Air Traffic Flow Management
ATIS	†Automatic Terminal Information Service
ATM	Air Traffic Management
ATN	Aeronautical Telecommunication Network
ATS	Air Traffic Service
ATSU	Air Traffic Service Unit
ATZ	Aerodrome Traffic Zone
AU	Airspace Utilisation
AUP	Airspace Utilisation Plan
AUW	All Up Weight
AUX	Auxiliary
AVBL	Available OR Availability
AVGAS	†Aviation Gasoline
AVTUR	Aviation Turbine Fuel
AWR	Air Weapon Range
AWY	Airway
AZM	Azimuth
B - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
BA	Braking Action
BBMF	Battle of Britain Memorial Flight
BCN	Beacon (Aeronautical ground light)
BDRY	Boundary
BFR	Before
BKN	Broken
BLCP	Base Level Change Point
BLDG	(ENR 5.4) Miscellaneous Tower; Tower on Structure; Apartment/Hotel with Flat Roof; Building, General (All Types); Observation Tower; Commercial Building, General; Observatory; Dwelling, Multi-Family; Stadium, Domed; Hospital, General; Commercial Building with Curved Roof; Ferris Wheel; Water-Tower Building, Masonary/Concrete; Building General (All Types); Transformer Yard; Commercial Building, Circular with Flat Roof; Capitol Building; Commercial Building with Flat Roof; Commercial/Recreational Structure, General.
BLO	Below Clouds
BLW	Below…
BOMB	Bombing
BOTA	Brest Oceanic Transition Area
BR	Mist
BRDG	(ENR 5.4) Bridge Tower; Suspension Bridge; Bridge, General; Arch
BRF	Short (Used to indicate the type of approach desired or required)
BRG	Bearing
BRKG	Braking
B-RNAV	†Basic - (To be pronounced 'AR-NAV') Area Navigation
BS	Commercial Broadcasting Station
BTL	Between Layers
BTN	Between
BVLOS	Beyond Visual Line Of Sight
C - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
C	Degrees Celsius (Centigrade)
CAA	Civil Aviation Authority
CANP	Civil Aircraft Notification Procedure
CAP	Civil Aviation Publication
CAS	Controlled Airspace
CAT	Clear Air Turbulence
CATZ	Combined Aerodrome Traffic Zone
CAVOK	†(To be pronounced 'KAV-OH-KAY') Visibility, cloud and present weather better than prescribed values or conditions
CBA	Cross Border Area
CC	Counter Clockwise
CDN	Co-ordination (message type designator)
CDR	Conditional Route
CH	Channel
CHAPI	Compact Helicopter Approach Path Indicator
CHG	Modification (message type designator)
CHIM	(ENR 5.4) Smokestack, General; Thermal Power-Plant Smokestack
CI	Cirrus
CIDIN	†Common ICAO Data Interchange Network
CIV	Civil
CL	Centre-Line
CLBR	Calibration
CLG	Calling
Cloud Ceiling:	In relation to an aerodrome, the distance measured vertically from the notified elevation of the aerodrome to the lowest part of any cloud visible from the aerodrome which is sufficient to obscure more than one half of the sky so visible.
CLR	Clear(s) OR Cleared to … OR Clearance
CLSD	Close OR Closed OR Closing
CM	Centimetre
CMATZ	Combined Military Aerodrome Traffic Zone
CMB	Climb to OR Climbing to
CMPL	Completion OR Completed OR Complete
CNL	Flight Plan Cancellation (message type designator)
CNS	Communications, Navigation and Surveillance
COM	Communications
Competent ATS Authority:	Means in relation to the UK, the Civil Aviation Authority, and in relation to any other country the authority responsible under the law of that country for promoting the safety of civil aviation.
CONC	Concrete
COND	Condition
CONS	Continuous
CONST	Construction OR Constructed
CONT	Continue(s) OR Continued
Continuous Descent Approach (CDA):	A noise abatement technique for arriving aircraft in which the pilot, when given descent clearance below Transition Altitude by ATC, will descend at the rate he judges will be best suited to the achievement of continuous descent, whilst meeting the ATC speed control requirements, the objective being to join the glidepath at the appropriate height for the distance without recourse to level flight
COOL	(ENR 5.4) Cooling Tower, Industrial
COOR	Co-ordinate OR Co-ordination
COORD	Geographical Co-ordinates
COP	Change-Over Point
COR	Correct OR Correction OR Corrected (Used to indicate corrected meteorological message; message type designator)
COV	Cover OR Covered OR Covering
CPDLC	Controller to Pilot Data link
CPL	Current Flight Plan (message type designator)
CRAM	Conditional Route Availability Message
CRN	(ENR 5.4) Rotating Crane on Tower, Industrial; Rotating Crane, Industrial; Bridge Crane, Industrial
CRZ	Cruise
CTA	Control Area
CTAM	Climb to and Maintain
CTC	Contact
CTL	Control
CTN	Caution
CTOT	Calculated Take-off Time
CTR	Control Zone
CUST	Customs
CWY	Clearway
D - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
D....	DME Range (prefix used in graphics)
D…	Danger Area (Followed by Identification)
DA	Decision Altitude
D-ATIS	Data Link Automatic Terminal Information Service
DCKG	Docking
DCT	Direct (In relation to flight path clearances and type of approach)
DEG	Degrees
DEMO	Demonstration
DEP	Departure (message type designator)
DER	Departure End of the Runway
DES	Descend to OR Descending to
DEST	Destination
DETRESFA	†Distress Phase
DEV	Deviation OR Deviating
DF	Direction Finding
DfT	Department for Transport
DFTI	Distance from Touchdown Indicator
DH	Decision Height
DIST	Distance
DIV	Divert OR Diverting
DLA	Delay OR Delayed
DLY	Daily
DME	‡Distance Measuring Equipment
DNG	Danger OR Dangerous
DNM	Directorate Network Management
DOC	Designated Operational Coverage
DOM	Domestic
DPT	Depth
DR	Dead Reckoning
DRA	Direct Route Airspace
DRDF	Digital Resolution Direction Finding
DRG	During
Dropping Zone/Drop Zone:	Means the notified portion of airspace within which parachute descents are made.
DTAM	Descend to and Maintain
DTG	Date-Time Group
DU	Dust
DUC	Dense Upper Cloud
DUR	Duration
DVOR	Doppler VOR
DW	Dual Wheels
E - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
EASA	European Union Aviation Safety Agency
EAT	Expected Approach Time
ECA	Emergency Controlling Authority
ECAC	European Civil Aviation Conference
EDT	Estimated Departure Time
EET	Estimated Elapsed Time
EFC	Expected Further Clearance
EFIS	†Electronic Flight Instrument System
EGNOS	European Geostationary Navigation Overlay Service
EHF	Extremely High Frequency (30000 to 300000 MHz)
ELBA	†Emergency Location Beacon - Aircraft
ELEV	Elevation
ELR	Extra Long Range
ELT	Emergency Locator Transmitter (GEN 3.6.6)
EMBD	Embedded in a Layer (To indicate cumulonimbus embedded in layers of other clouds)
EMERG	Emergency
END	Stop-end (related to RVR)
ENG	Engine
ENR	En-Route
EOBT	Estimated Off-Block Time
EQPT	Equipment
EST	Estimate OR Estimated OR Estimate (message type designator)
ETA	*‡Estimated Time of Arrival OR Estimating Arrival
ETD	‡Estimated Time of Departure OR Estimating Departure
ETFMS	Enhanced Tactical Flight Management System
ETOPS	Extended Twin-jet Operations
EXC	Except
EXER	Exercises OR Exercising OR To Exercise
EXP	Expect OR Expected OR Expecting
EXT	Extension
EXTD	Extend OR Extending
F - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
FAC	Facilities
FAF	Final Approach Fix
FAM	Flight Activation Monitoring
FAP	Final Approach Point
FAS	Final Approach Segment
FAT	Final Approach Track
FATO	Final Approach and Take-off Area
FBL	Light (Used to indicate the intensity of weather phenomena, interference or static reports, eg FBL RA = Light rain)
FBO	Fixed-base Operator
FBU	Flight Briefing Unit
FBZ	Flight Plan Buffer Zone
FCT	Friction Coefficient
FDOD	Flight Data Operations Division
FDPS	Flight Data Processing System
FIC	Flight Information Centre
FIR	‡Flight Information Region
FIS	Flight Information Service
FISA	Automated Flight Information Service
FISO	Flight Information Service Officer
FL	Flight Level
FLAS	Flight Level Allocation Scheme
FLG	Flashing
FLR	(ENR 5.4) Flare Pipe - On Land (In Refinery)
FLT	Flight
FLTCK	Flight Check
FLY	Fly OR Flying
FM	From
FMC	Flight Management Computer
FMD	Flow Management Division
FMP	Flow Management Position
FMS	Flight Management System
FMU	Flow Management Unit
FNA	Final Approach
FOD	Foreign Object Damage/Debris
FPL	Filed Flight Plan (message type designator)
FPM	Feet Per Minute
FPR	Flight Plan Route
FRA	Free Route Airspace
FRA (A)	FRA Arrival Connecting Point
FRA (D)	FRA Departure Connecting Point
FRA (E)	FRA Horizontal Entry Point
FRA (I)	FRA Intermediate Point
FRA (X)	FRA Horizontal Exit Point
FREQ	Frequency
FRNG	Firing
FRQ	Frequent
FRZ	Flight Restriction Zone
FSL	Full Stop Landing
FSS	Flight Service Station
FT	Feet (Dimensional Unit)
FU	Smoke
FUA	Flexible Use of Airspace
G - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
G/A	Ground-to-Air
G/A/G	Ground-to-Air and Air-to-Ground
GA	General Aviation
GAGAN	GPS & Geostationary Earth Orbit Augmented Navigation
GAMET	General Aviation Meteorological Forecast
GAT	General Air Traffic
GBAS	Ground Based Augmentation System
GCA	‡Ground Controlled Approach System OR Ground Controlled Approach
General Air Traffic (GAT):	Flights conducted in accordance with the Regulations and Procedures for flight promulgated by the State Civil Aviation Authorities and operating under the control or authority of the Civil ATS organisation.
GEO	Geographic OR True
GES	Ground Earth Station
GLD	Glider
GLONASS	Global Orbiting Navigation Satellite System
GLS	‡GBAS Landing System
GMC	Ground Movement Control
GMR	Ground Movement Radar
GND	Ground
GNSS	Global Navigation Satellite System
GP	Glide Path
GPA	Glide Path Angle
GPS	Global Positioning System
GPWS	‡Ground Proximity Warning System
GR	Hail
GRAS	Ground Based Regional Augmentation system
GRASS	Grass Landing Area
GRVL	Gravel
GS	Ground Speed
GUND	Geoid Undulation
GVS	Gas Venting Site
H - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
H24	Continuous Day and Night Service
HAPI	Helicopter Approach Path Indicator
HBN	Hazard Beacon
HDF	High Frequency Direction-Finding Station
HDG	Heading
HEL	Helicopter
HEMS	Helicopter Emergency Medical Service
HF	‡High Frequency (3000 to 30000 kHz)
HGT	Height OR Height Above
HI	High Intensity directional lights
HIAL	Highlands and Islands Airports Ltd
HIRTA	High Intensity Radio Transmission Area
HJ	Sunrise to sunset
HLA	High Level Airspace
HLDG	Holding
HMRI	Helicopter Main Routing Indicator
HMU	Height Monitoring Units
HN	Sunset to Sunrise
HO	Service available to meet operational requirements
HOL	Holiday
HOPA	Helicopter Operational Area
HOSP	Hospital Aircraft
HOZ	Helicopter Operating Zone
HPA	Hectopascal
HR	Hours
HS	Service Available During Hours of Scheduled Operations
HT	High Tension (power)
HTA	Helicopter Training Area
HVDF	High and Very High Frequency Direction Finding Stations (At the Same Location)
HVY	Heavy
HX	No Specific Working Hours
Hz	Hertz (Cycle Per Second)
I - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
IAC	Instrument Approach Chart
IAF	Initial Approach Fix
IAP	Instrument Approach Procedure
IAR	Intersection of Air Routes
IAS	Indicated Air Speed
IBN	Identification Beacon
ID	Identifier OR Identify
IDENT	†Identification
IF	Intermediate Approach Fix
IFF	Identification Friend/Foe
IFPS	Integrated Flight Planning System
IFR	‡Instrument Flight Rules
IGA	International General Aviation
ILS	‡Instrument Landing System
IM	Inner marker
IMC	‡Instrument Meteorological Condition
IMT	Immediate OR Immediately
INA	Initial Approach
INBD	Inbound
INC	In Cloud
INCERFA	†Uncertainty Phase
INFO	†Information
INOP	Inoperative
INS	Inertial Navigation System
INSTL	Install OR Installed OR Installation
INSTR	Instrument
INT	Intersection
INTL	International
INTSF	Intensify OR Intensifying
INTST	Intensity
IRS	Inertial Reference System
IRVR	Instrumented Runway Visual Range
ISA	International Standard Atmosphere
ISOL	Isolated
J - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
JMC	Joint Maritime Course
JTST	Jet Stream
K - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
KG	Kilogrammes
KHz	Kilohertz
KIAS	Knots Indicated Airspeed
KM	Kilometres
KMH	Kilometres per Hour
Known Traffic:	Traffic the current flight details and intentions of which are known to the controller concerned through direct communication or co-ordination.
KPA	Kilopascal
KT	Knots
KW	Kilowatts
L - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
L	Locator (NDB with published approach procedure. See LM, LO)
LAM	Logical Acknowledgement (message type designator)
LARS	Lower Airspace Radar Service
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)
LFA	Low Flying Area
LFC	Low Flying Co-ord
LFZ	Low Flying Zone
LGT	Light OR Lighting
LGTD	Lighted
LHA	Lowest Holding Altitude
LHS	Left hand side
LI	Low Intensity omni-directional lights
LIH	Light Intensity High
LIL	Light Intensity Low
LIM	Light Intensity Medium
LITAS	Low Intensity Two Colour Approach Slope Indicators at …… and …… metres from threshold bracketing approach angle of …… degrees
LM	Locator, Middle
LNAV	† (to be pronounced “EL-NAV”) Lateral Navigation
LNG	Long (Used to indicate the type of approach desired or required)
LO	Locator, outer
LOC	Localizer
LONG	Longitude
LORAN	†LORAN (Long Range Air Navigation System)
Low Power/Low Drag Approach (LP/LD):	A noise abatement technique for arriving aircraft in which the pilot delays the extension of wing flaps and undercarriage until the final stages of the approach, subject to compliance with ATC speed control requirements and the safe operation of the aircraft.
LPV	Localizer Performance with Vertical Guidance
LTD	Limited
LV	Light and Variable (Relating to Wind)
LVL	Level
LVP	Low Visibility Procedures
M - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
M	Metres (Preceded by figures)
MAA	Maximum Authorised Altitude
MAG	Magnetic
MAINT	Maintenance
MAP	Aeronautical maps and charts
MAPt	Missed Approach Point
MAS	Manual A1 Simplex
MASA	Multifunctional Transport Satellite (MTSAT) Satellite Based Augmentation System
MATZ	Military Aerodrome Traffic Zone
MAUW	Maximum All Up Weight
MCA	Minimum Crossing Altitude
MDH	Minimum Descent Height
MEA	Minimum En-route Altitude
MEDA	Military Emergency Diversion Aerodrome
MEHT	Minimum Eye Height over Threshold (For VASIS and PAPI)
MET	(ENR 5.4) Meteorological Mast
METAR	†Aviation routine weather report (In aeronautical meteorological code)
MF	Medium Frequency (300 to 3000 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 RVR)
MIL	Military
MINE	(ENR 5.4) Mine Shaft Superstructure
MISC	(ENR 5.4) Miscellaneous Air Obstruction (Man Made)
MKR	Marker radio beacon
MLAT	Multilateration
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)
MOCA	Minimum Obstacle Clearance Altitude
MOD	Moderate (Used to indicate the intensity of weather phenomena, interference or static reports, eg MOD RA = Moderate rain)
MOGAS	Motor Gasoline
MONT	(ENR 5.4) Monument/Obelisk
MPH	Statute Miles Per Hour
MPS	Metres Per Second
MRP	ATS/MET Reporting Point
MS	Minus
MSA	Minimum Sector Altitude
MSG	Message
MSL	Mean Sea Level
MTA	Military Training Area
MTOM	Maximum Take-off Mass
MTOW	Maximum Take-off Weight
MTRA	Military Temporary Reserved Airspace
MTU	Metric Units
MTWA	Maximum Total Weight Authorised
MVDF	Medium and Very High Frequency Direction Finding Stations (At the same location)
MWO	Meteorological Watch Office
N - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
N	No distinct tendency (in RVR during previous 10 minutes)
NADP	Noise Abatement Departure Procedure
NAT	North Atlantic
NAV	Navigation
NB	Northbound
NBFR	Not Before
NC	No Change
NDB	‡Non-Directional Radio Beacon
NDS	Non Deviating Status
NEG	No OR Negative OR Permission not granted OR That is not correct
NERS	North Atlantic European Routing System
NGT	Night
Night:	The time between half an hour after sunset and half an hour before sunrise, sunset and sunrise being determined at surface level.
NIL	*†None OR I Have nothing to send to you
NM	Nautical Miles
NML	Normal
NOF	International NOTAM Office
NOSIG	†No Significant Change (Used in trend -type landing forecasts)
NOTA	Northern Oceanic Transition Area
NOTAM	†A notice containing information concerning the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel concerned with flight operations
NPA	Non Precision Approach
NPR	Noise Preferential Routeing
NPZ	Non-standard Planning Zone
NSC	Nil Significant Cloud
NSF	Non Standard Flights
NSGA	Non-SSR Glider Areas
NSU	Nominated Service Unit
NSW	Nil Significant Weather
NVG	Night Vision Goggles
O - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
O/R	On Request
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	Oceanic Control Area
OCH	Obstacle Clearance Height
OCL	Oceanic Clearance Link
OCNL	Occasional OR Occasionally
OCS	Obstacle Clearance Surface
OFZ	Obstacle Free Zone
OHD	Overhead
OIL	(ENR 5.4) Refinery
OLDI	On-Line Data Interchange
OM	Outer Marker
Operational Air Traffic (OAT):	Flights conducted under the control or authority of the military ATS organisation.
OPH	(ENR 5.4) Offshore Platform with Helipad
OPMET	†Operational Meteorological (information)
OPR	Operator OR Operate OR Operative OR Operating OR Operational
OPS	†Operations
OPSLF	MOD Operations Low Flying
ORCA	Oceanic Route Clearance Authorisation System
OSA	Off-shore Safety Area
OSV	Ocean Station Vessel
OTS	Organised Track System
OUBD	Outbound
P - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
P…	Prohibited area (Followed by identification)
PALS	Precision Approach Lighting System (Specify category)
PAMOS	Partially Automated MET Observation System
PANS	Procedures for Air Navigation Services
PAPA	Parallax Aircraft Parking Aid
PAPI	†Precision Approach Path Indicator
PAR	‡Precision Approach Radar
Parachute Landing Area:	Means the terrain onto which parachute descents are made.
PAX	Passenger(s)
PBN	Performance-based Navigation
PCN	Pavement Classification Number
PCR	Pavement Classification Rating
PDG	Procedure Design Gradient
PER	Performance
PERM	Permanent
PFS	(ENR 5.4) Floating Production Storage Offloading
PGL	(ENR 5.4) Gas Lift Platform
PH	Public Holiday
PIB	Pre-flight Information Bulletin
PJE	Parachute Jumping Exercise
PLA	Practice Low Approach
PLN	Flight Plan
PLT	(ENR 5.4) Power Plant; Industrial Structure, General; Tank, Telescoping Gasholder (Gasometer); Metal Processing Plant; Chemical Processing Plant; Tailings/Waste Pipe
PN	Prior Notice required
PNdB	Perceived Noise Decibels
PNR	Point of No Return
POB	Persons On Board
POSS	Possible
POW	(ENR 5.4) House of Religious Worship with Steeple; House of Religious Worship (Church/Mosque/Synagogue/Temple)
PPL	(ENR 5.4) Offshore Platform with Derrick
PPP	(ENR 5.4) Offshore Platform
PPR	Prior Permission Required
PRI	Primary
PRKG	Parking
PROB	†Probability
PROC	Procedure
PROV	Provisional
PSG	Passing
PSN	Position
PSR	Primary Surveillance Radar
PTN	Procedure Turn
PTS	Polar Track Structure
PWR	Power
PYL	(ENR 5.4) Aerial Cable/Aerial Tramway or Power Transmission Line; Powerline Pylon, General; Powerline Pylon, Type A
Q - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
QDM	‡Magnetic Heading (zero wind)
QDR	Magnetic Bearing
QFE	‡Atmospheric pressure at aerodrome elevation (OR at runway threshold)
QFU	Magnetic orientation of runway
QNH	‡Altimeter sub-scale setting to obtain elevation when on the ground
QTE	True bearing
R - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
R	Right (runway identification)
R....	Radial (prefix for use in graphics)
R…	Restricted Area (followed by identification)
RA	Resolution Advisory
RA(T)	Restricted Area (Temporary)
RAC	Rules of the Air and Air Traffic Services
RAD	Route Availability Document
Radar Clear Range:	A range surveyed by radar within which the operating authority accepts responsibility for withholding fire if an aircraft is within the area into which, and through which, missiles are liable to fall.
Radar Departure:	The control of a departing aircraft by the use of surveillance radar to assist it to leave the vicinity of an aerodrome safely and expeditiously.
Radar Handover:	Transfer of responsibility for the control of an aircraft between two controllers using radar , following identification of the aircraft by both controllers.
Radar Surveillance:	Observance of the movements of aircraft on a radar display and the passing of advice and information to identified aircraft and, where appropriate, to other ATS Units.
Radial:	A magnetic bearing extending from a VOR/VORTAC/TACAN.
RAF	Royal Air Force
RAFAT	Royal Air Force Aerobatic Team
RAFCT	Royal Air Force Combined Training
RAG	Runway Arresting Gear
RAI	Runway Alignment Indicator
RAS	Radar Advisory Service
RASA	Radar Advisory Service Area
RASC	Regional AIS System Centre
RB	Rescue boat
RCC	Rescue Co-ordination Centre
RCF	Radio Communication Failure (message type designator)
RCL	Runway Centre Line
RCLL	Runway Centre Line Light(s)
RDH	Reference Datum Height (For ILS)
RDL	Radial
RDO	Radio
REC	Receive OR Receiver
REDL	Runway Edge Light(s)
REF	Reference to … OR Refer to …
REG	Registration
REQ	Request OR Requested
RERTE	Re-route
RESA	Runway End Safety Area
RET	Rapid Exit Taxiway
RETIL	Rapid Exit Taxiway Indicator Lights
RFF	Fire and Rescue Equipment
RHAG	Rotary Hydraulic Arrester Gear
RHS	Right hand side
RIS	Radar Information Service
RL	Report Leaving
RLCE	Request Level Change En-route
RLLC	Royal Low Level Corridor
RLLS	Runway Lead-in Lighting System
RLNA	Requested Level Not Available
RMA	Radar Manoeuvring Area
RMK	Remark
RMZ	A Radio Mandatory Zone (RMZ) is defined as airspace of defined dimensions wherein the carriage and operation of radio equipment is mandatory.
RN	Royal Navy
RNAV	†(To be pronounced 'AR-NAV') Area Navigation
RNG	Radio Range
RNHF	Royal Navy Historical Flight
RNP	‡Required Navigation Performance
ROBEX	†Regional OPMET Bulletin Exchange (Scheme)
ROD	Rate Of Descent
RON	Receiving Only
ROP	Runway Observation Position
RPL	Repetitive flight plan
RPLC	Replace OR Replaced
RPS	Radar Position Symbol
RPZ	Runway Protection Zone
RQMNTS	Requirements
RQP	Request flight plan (message type designator)
RQS	Request supplementary flight plan (message type designator)
RR	Report Reaching
RRA	(OR RRB, RRC . . . . etc, in sequence) Delayed meteorological message (message type designator)
RSCD	Runway Surface Condition
RSP	Responder beacon
RSR	En-Route Surveillance Radar
RTE	Route
RTF	Radiotelephone
RTG	Radiotelegraph
RTHL	Runway threshold light(s)
RTILS	Runway Threshold Identification Lights
RTM	(ENR 5.4); Communication Tower; Microwave Tower, Type A (Has Reflector/Cone); Radio/TV Tower Type A; Microwave Tower, Type I (Has Reflector/Cone)
RTOAA	Rejected Take-off Area Available
RTODAH	Rejected Take-off Distance Available, Helicopter
RTR	Radar Termination Range
RTS	Return To Service
RTT	Radioteletypewriter
RTZL	Runway Touchdown Zone Light(s)
RV	Rescue Vessel
RVA	Radar Vectoring Area
RVP	Rendezvous Point
RVR	‡Runway Visual Range
RVSM	Reduced Vertical Separation Minimum
RWY	Runway
S - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
SALS	Simple Approach Lighting System
SAMOS	Fully automated with computer generated ATIS attached
SAR	Search and Rescue
SARPS	Standards and Recommended Practices (ICAO)
SARSAT	Search and Rescue Satellite Aided Tracking System
SATCOM	†Satellite Communication
SBAS	Satellite Based Augmentation System
ScACC	Scottish Area Control Centre
ScATCC	Scottish Area and Terminal Control Centre
SDBY	Stand by
SDF	Step Down Fix
SEC	Seconds
SECT	Sector
SEG	Stand Entry Guidance
SELCAL	†Selective calling system
Semicircular Cruising Level	Specified cruising levels determined in relation to magnetic track within hemispheres of the compass.
SER	Service OR Servicing OR Served
SERA	Standardised European Rules of the Air (Commission Implementing Regulation (EU) No 923/2012).
SFC	Surface
SGL	Signal
SHF	Super High Frequency (3000 to 30000 MHz)
SI	Statutory Instruments
SID	†Standard Instrument Departure
SIGMET	†Information concerning en-route weather phenomena which may affect the safety of aircraft operations
SIGWX	Significant weather
SIWL	Single Isolated Wheel Load
SKED	Schedule OR Scheduled
SLP	Speed Limiting Point
SMC	Surface Movement Control
SMR	Surface Movement Radar
SNOCLO	Aerodrome closed due to snow (used in METAR/SPECI)
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.
SOC	Start of Climb
SOTA	Shannon Oceanic Transition Area
SPECI	†Aviation selected special weather report (In aeronautical meteorological code)
SPECIAL	†Special meteorological report (In abbreviated plain language)
SPL	Supplementary flight plan (message type designator)
SR	Sunrise
SRA	Surveillance Radar Approach
SRD	Standard Route Document
SRE	Surveillance Radar Element of precision approach radar system
SRR	Search and Rescue Region
SRY	Secondary
SS	Sunset
SSR	‡Secondary Surveillance Radar
SST	Supersonic transport
STA	Straight in approach
Stack Departure Time:	The time at which an aircraft is required to leave the holding facility to commence its approach.
STAR	†Standard instrument arrival
STD	Standard
STOL	Short Take-Off and Landing
STS	Status
STWL	Stopway light(s)
SUA	Special Use Airspace (includes prohibited areas, restricted areas, danger areas, temporary segregated areas, temporary reserved areas and cross border areas)
SUAAIS	Special Use Airspace Activity Information Service
SUACS	Special Use Airspace Crossing Service
SUBJ	Subject to
SUP	Supplement (AIP Supplement)
SUPPS	Regional supplementary procedures
SVC	Service message
SVCBL	Serviceable
SVFR	Special Visual Flight Rules
SWY	Stopway
T - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
TA	Transition Altitude
TAA	Terminal Arrival Altitude
TACAN	†UHF Tactical Air Navigation Aid
TAF	†Aerodrome forecast
TAR	Terminal Area Surveillance Radar
TAS	True Airspeed
TC	Tropical Cyclone
TCAS	Traffic Alert and Collision Avoidance System
TCH	Threshold Crossing Height
TDA	Temporary Danger Area
TDZ	Touch Down Zone
TECR	Technical Reason
TEL	Telephone
TEMPO	†Temporary OR Temporarily
TFC	Traffic
TGL	Touch-and-Go Landing
TGS	Taxiing Guidance System
THR	Threshold
TKOF	Take-off
TLOF	Touchdown and Lift-off Area
TMA	‡Terminal Control Area
TMZ	A Transponder Mandatory Zone (TMZ) is defined as airspace of defined dimensions wherein the carriage and operation of pressure-altitude reporting transponders is mandatory.
TNH	Turn Height
TO	To. . . . (place)
TOC	Top Of Climb
TODA	Take-off Distance Available
TODAH	Take-off Distance Available, Helicopter
TORA	Take-off Run Available
TP	Turning Point
TR	Track
TR.....	Temporary Reserved Area (Followed by Identification)
TRA	Temporary Reserved Area
TRAG	Temporary Reserved Areas (Gliding)
TRANS	Transmits OR Transmitter
Transition Altitude	The altitude at or below which the vertical position of an aircraft is controlled by reference to altitudes.
Transition Layer	The airspace between the transition altitude and the transition level.
Transition Level	The lowest flight level available for use above the transition altitude.
TRL	Transition Level
TRP	Tug Release Point
TS.....	Temporary Segregated Area (Followed by Identification)
TSA	Temporary Segregated Area
TURB	Turbulence
TURB-OFF	(ENR 5.4) Windmotor/Wind Powered Generator - Located Off Shore
TURB-ON	(ENR 5.4) Windmotor/Wind Powered Generator - Located On Land
TVOR	Terminal VOR
TWR	Aerodrome control tower OR aerodrome control
TWY	Taxiway
TWYL	Taxiway-Link
TYP	Type of Aircraft
U - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
U/S	Unservicable
UAA	Unusual Aerial Activity
UAC	Upper Area Control Centre
UAR	Upper Air Route
UAS	Unmanned Aircraft System
UAV	Unmanned Aerial Vehicle
UDF	Ultra High Frequency Direction Finding Station
UFN	Until Further Notice
UHF	‡Ultra High Frequency (300 to 3000 MHz)
UIC	Upper Information Centre
UIR	‡Upper Flight Information Region
UK	United Kingdom
UK FIS	UK Flight Information Service/Services
UK Flight Information Service/Services	UK Flight Information Service/Services (UK FIS). ICAO defines FIS: As a service provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights. Within the UK, the scope of FIS as defined in ICAO Annex 11 is met through the application of any of the UK FIS. However, additional information and/or advice to airspace users are provided to meet their specific requirements. The suite of services together form the UK FIS as detailed in CAP 774 - UK Flight Information Services.
ULR	Ultra Long Range
UNAP	Unable to Approve
UNL	Unlimited
UNREL	Unreliable
Upper ATS Route:	A designated route within the Upper Airspace CTA.
UTA	Upper Control Area
UTC	‡Co-ordinated Universal Time
V - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
VA	Volcanic Ash
VAC	Visual Approach Chart
VAN	Runway Control Van
VAR	Visual-aural radio range
VASIS	†Visual Approach Slope Indicator System
VCY	Vicinity
VDF	Very High Frequency Direction Finding Station
VFR	‡Visual Flight Rules
VHF	‡Very High Frequency (30 to 300 MHz)
VIP	‡Very Important Person
VIS	Visibility
VLF	Very Low Frequency (3 to 30 KHz)
VLOS	Visual Line Of Sight
VLR	Very Long Range
VM(C)	Visual Manoeuv ring (Circling)
VMC	‡Visual Meteorological Conditions
VOLMET	†Meteorological information for aircraft in flight
VOR	‡Very High Frequency Omnidirectional Radio Range
VORTAC	†VOR and TACAN combination
VPT	Visual manoeuvre with prescribed track
VRB	Variable
VRP	Visual Reference Point
VSP	Vertical speed
VSTOL	Very Short Take-Off and Landing
VTOL	Vertical Take-Off and Landing
W - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
WAAS	Wide Area Augmentation System
WAC	World Aeronautical Chart — ICAO 1:1 000 000
WAFC	World Area Forecast Centre
WASTE	(ENR 5.4) Disposal, General
WBAR	Wing bar lights
WDI	Wind Direction Indicator
WEF	With Effect From OR Effective From
WGS	World Geodetic System
WIE	With Immediate Effect OR Effective Immediately
WILCO	†Will comply
WIP	Work In Progress
WPT	Way-point
WRNG	Warning
WS	Windshear
WT	Weight
WX	Weather
X - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
X	Cross
XBAR	Crossbar (of approach lighting system)
XNG	Crossing
Y - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
YCZ	Yellow caution zone (runway lighting)
Z - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Z	Co-ordinated Universal Time