Abbreviations

The Trevor Thom Series of Pilot Manuals does not include a complete list of abbreviations and they are usually only described once in the text so I thought it might be useful to list them for ready reference. I have also listed hundreds of others most of which are more useful to more advanced pilots.

A

A - Aeroplane, Alpha(phonetic alphabet), Altimeter(for QNH in Mercury)
AA - Amended
AAAE - American Association of Airport Executives
AAE - Accredited Airport Executive
AAF - Airway Facilities Service
AAI - FAA Office of Accident Investigation
AAIU - Air Accident Investigation Unit
AAL – Above Aerodrome Level
ABn - Aerodrome Beacon
A/C - Aircraft, Airconditioning Unit
Ac(or AC) - Altocumulus
AC - Alternating Current, Advisory Circular
ACAS - Airborne Collision Avoidance System
ACARS - Aircraft Communciations and Addressing and Reporting System
ACC - Area Control Centre
ACI - Airport Council International
ACT - Active or Activated or Activity
AD – Aerodrome/Aerodrome Data, Airworthiness Directive(FAA)
ADA - Advisory Area
ADB - Airports Database
ADC - Air Data Computer
ADELT - Automatically Deployable Emergency Locator Transmitter
ADEXP - ATS Data Exchange
ADIZ - Air Defence Identification Zone
ADF – Automatic Direction Finder
ADI – Attitude Direction Indicator
ADR - Advisory Route
ADS - Automatic Dependent Surveillance
ADT - Approved Departure Time
AES - Aircraft Earth Station
AF - Audio Frequency
AFC - Area Forecast Centre
AFCS - Automatic Flight Control System
A/FD - Airport Facility Directory
AFD - Adaptive Flight Display
AFDS - Autopilot Flight Director System
AFIL - Flight Plan filed in the air
AFIS - Aerodrome Flight Information Service
AFISO - Aerodrome Flight Information Service Officer
AFM - Aeroplane Flight Manual
AFS - Aeronautical Fixed Service, Aerodrome Fire Service
AFTN - Aeronautical Fixed Telecommunications Network
AG - Arrester Gear
A/G - Air/Ground Radio Station
AGA - Aerodrome Ground Aid
AGL – Above Ground Level
AHRS - Attitude-Heading Reference System
AI – Attitude Indicator (Artificial Horizon)
AIAA – Area of Intense Aerial Activity
AIB - Aerodrome Information Bulletin
AIC – Aeronautical Information Circular
AIP – Aeronautical Information Publication, (GEN) General, (ENR) EN Route (AD) AeroDrome
AIRAC - Aeronautical Information Regulation And Control
AIREP - Air Report
AIRMET - Aircraft Meteorological Service
AIRPROX - Aircraft Proximity (near miss) AIS - Aeronautical Information Services
ALT – Altimeter, Altitude
ALTN - Alternate
AM - Amplitude Modulation
AMC - Acceptable Means of Compliance, Aeromedical Centre
AMD - Amended
AME - Authorised/Aeronautical/Aviation Medical Examiner
amps - Amperes
AMLCD - Active-Matrix Liquid Crystal Display
AMSL – Above Mean Sea Level
ANDS - Acceleration apparent turn North, Deceleration apparent turn South
ANGR - Air Navigation General Requirements
ANM – Air Nautical Mile
ANO – Air Navigation Order
ANR - Air Navigation Regulation
ANS - Active Noise System
ANT – Antenna
AoA - Angle of Attack
AO - Aircraft Operator
AOC - Aircraft Owner's Certificate
AOG - Aircraft on Ground
AOPA - Aircraft Owner's and Pilot's Association
AOR-E - Atlantic Ocean Region East
A & P - Airframe and Powerplant
AP - Airport, Autopilot, Approach
APP - Approach Control
APCH - Approach
APR - Auxiliary Power Reserve
APT – Attitude, Power, Trim
APU - Auxiliary Power Unit
ARFOR - Area Forecast
ARINC - Aeronautical Radio Incorporated
ARMET - Forecast upper wind and temperature at specified points
ARN - ATS Route Network
ARR - Arrival
ARTAS - ATM Surveillance Tracker and Server
ARTIFAX - Facsimile Broadcast Service
As(or AS) - Altostratus
ASA - Autoland Status Annuniciator
ASAP - As Soon As Possible
ASCB - Avionics Standard Communication Bus
ASDA - Accelerate-Stop Distance Available
ASI – Airspeed Indicator
ASL – Above Sea Level
ASM - Airspace Management
ASR – Altimeter Setting Regions, Approach Surveillance Radar
AT - At(weather)
A/T - Auto Throttle
ATA – Aerial Tactics Areas, Actual Time of Arrival
ATAS - Air Traffic Advisory Service
ATC - Air Traffic Control
ATCC - Air Traffic Control Centre
ATCO - Air Traffic Control Officer
ATD – Actual Time of Departure
ATE - Actual Time Enroute
ATFM - Air Traffic Flow Management
ATIS – Air Traffic Information Service
ATM - Air Traffic Management
ATMC - Air TRaffic Managment Centre
ATN - Aeronautical Telecommunications Network
ATP - Airline Transport Pilot
ATPL – Air Transport Pilot License
ATS - Air Traffic Service
ATSU – Air Traffic Service Unit
ATTN - Attention
ATZ – Aerodrome Traffic Zones
AUW - All-Up Weight
AUX - Auxiliary
AVIONICS - AVIation electrONICS
AVGAS - Aviation Gasoline (100LL - Low Lead)
AVTUR - Aviation Turbine Fuel[kerosene] (same as JetA1)
AWACS - Airborne Warning And Control System
AWY - Airway
AZM - Azimuth

B

B - Bravo(phonetic alphabet), Blue
BAA - British Airports Authority
BALPA - British Airline Pilot's Association
BASE - Cloudbase
BBAC - British Balloon and Airships' Club
BC - Patches(of cloud)
BCAR - British Civil Airworthiness Requirements
BCD - Binary Coded Decimal
BCF – BromoChloridiFluoromethane (Halon Fire Extinguisher)
BCN – Beacon
BCP - Break Cloud Procedures
BCPL - Basic Commercial Pilot's License
BCST - Broadcast
BDC - Bottom Dead Centre
BDRY - Boundary
BECMG - Becoming
BFO – Beat Frequency Oscillator, Blazing Flash of the Obvious
BFR - Biennial Flight Review(USA)
BHP - Brake Horsepower
BITE - Built-In Test Equipment
BKN - Broken
BL - BLowing
BLO - BeLOw clouds
BOW - Basic Operating Weight
BPPL - Basic Private Pilots License
BR - Mist
BRG - Bearing
BRITE - Bright Radar Indicator Tower Equipment
BRL - Building Restriction Lines
B-RNAV - Basic Area Navigation
BS - Commercial Broadcasting Station
BSU - Beam Steering Unit
BT - Basic Transport
BTN - BeTweeN
BTU - British Thermal Unit
BU - Basic Utility
BUMFICH - Brakes, Undercarriage, Mixture, Fuel & Flaps, Instruments, Carb Heat, Hatches & Harnesses(Downwind Check)
BUEC - Backup Emergency Communications

C

C - Charlie(phonetic alphabet), Celsius
CA – Closing Angle, Conflict Alert
CAA – Civil Aviation Authority, Civil Aeronautics Administration (or Authority)
CAB - Civil Aeronautics Board
CAIRDE - Civil Aviation Integrated Radar Display Equipment
CAMI - Civil Aeronautics Medical Institute
CANP – Low-Level Civil Aircraft Notification Procedure
CANSO - Civil Air Navigation Services Organisation
CAP – Civil Aviation Publication, Civil Air Patrol
CARB – Carburetor
CARF - Central Altitude Reservation Function
CAS - Calibrated Airspeed, Controlled Airspace
CASA - Computer-Assisted Slot Allocation
CAT - Clear Air Turbulence, Category, Commercial Air Transport/Traffic
CATI - Category I ILS (uses MALSR) CATII - Catgory II ILS (uses ALSF-2) CATIII - Category III ILS (uses ALSF-2) CAVOK - Ceiling And Visibility OK(weather)
CAVU - Ceiling And Visibility Unlimited
Cb(or CB) - Cumulonimbus
CB - Circuit Breaker
CBD - Central Business District
Cc(or CC) - Cirrocumulus
CC - Correction(weather)
CCC - Crew Coordination Concept
CCM - Chemically Correct Mixture
CD - Clearance Delivery, Coefficient of Drag(also Cdrag)
CDA - Continuous Descent Approach
CDI – Course Deviation Indicator
CDT - Controlled Departure Time
CDTI - Cockpit Display of Traffic Information
CDU - Control Display Unit
CE - Categorical Exclusion, Certificate of Engineering
CEPHACER - Callsign & Type, En Route, Position, Heading, Altitude, Conditions, Estimate, Request(if applicable)
CFI – Certified Flying Instructor
CFII - Certified Flying Instructor Instrument
CFIT - Controlled Flight Into Terrain
CFR - Code of Federal Regulations, Crash Fire Rescue
CFS - Cubic Feet per Second
CFW - Center Field Wind
CFWSU - Central Flow Weather Services Unit
CG – Centre of Gravity
CGI - Chief(or certified) Ground Instructor
CH - Compass Heading
CheckA - Daily Inspection
CHiRP - Confidential Human Factor's Reporting Programme
CHT - Cylinder Head Temperature
Ci(or CI) - Cirrus
CIC - Controller In Charge
CIP - Capital Investment Plan
CIR - CIRcuit flight operation
CIV - Civil
CL - Centerline lights, Coefficient of Lift(also Clift)
Cliftmax - Maximum Coefficient of Lift
CLD - Cloud
CLSD - Closed
CLUZ - Compatible Land Use Zones
CMA - Calcium Magnesium Acetate
CMATZ - Combined Military Aerodrome Traffic Zone
CMOS - Complementary Metal Oxide Semiconductor
CMU - Communications Management Unit
CNIPI - Callsign & Type, Nature of Emergency, Intention, Position, Information(anyhting else pertinent)
CNR - Composite Noise Rating
CNS - Continuous, Communications Navigation & Surveillance
CofA - Certificate of Airworthiness
CofE - Certificate of Experience
COM - Communications
CofT - Certificate of Test
COT - CoasTaL
CP – Centre of Pressure
CPA - Closest Point of Approach
CPL – Commercial Pilot License
CQB - Central Question Bank
CR - Class Rating
C/R - Counter-Rotating Propeller
CRAF - Civil Rescue Air Fleet
CRDA - Converging Runway Display Aid
CRE - Class Rating Examiner
CRI - Class Rating Instructor
CRM – Cockpit Resource Management
CRP - Compulspry Reporting Point
CRS - Crash Rescue Service
CRT – Cathode Ray Tube
C/S - Callsign
Cs(or CS) - Cirrostratus
CSDB - Commercial Standard Data Bus
CSS - Checkpoint Security Supervisors
CSU - Constant Speed Unit
CTA – Control Area, Controlled Time of Arrival
CTAF - Common Traffic Advisory Frequency
CTL - Control
CTN - Caution
CTR - Control Zone
Cu(or CU) - Cumulus
CUF - Cumuliform
CUST - Customs
CVR - Cockpit Voice Recorder
CW – Carrier Wave, Continuous Wave
CWA - Centre Weather Advisory
CWSU - Centre Weather Services Unit
CY - Cubic Yards
CZ - Control Zone

D

D -Delta(phonetic alphabet), Decreasing, Drag, Danger Area, Day
D&D - Distress and Diversion
DA - Decision Altitude, Density Altitude, Drift Angle
DAAIS - Danger Area Activity Information Service
DACS - Danger Area Crossing Service
DADC - Digital Air-Data Computer
DA(H) - DA & DH (Jeppesen approach charts)
DALR - Dry Adiabatic Lapse Rate
dB – Decibel
dBA - Decibels on the A Weighted
DC - Direct Current, Dual Control
D/C - Demand/Capacity Radio DCIA - Dependent Converging Instrument Approaches
DCT - Direct
DECR - Decrease/Decreasing
DEDS - Data Entry Display System
DEG - Degrees
DEIS - Draft Environmental Impact Statement
DEL - Delay/Delayed
DEP - Departure
DEST- Destination
DEV - Deviation
DF - Direction Finding
DFM - Departure Flow Management
DG – Directional Gyro(HI)
DGPS - Differential Global Positioning System - (LA) - Local Area (WA) - Wide Area
DH - Decision Height, Density Height
DI – Direction Indicator(HI), Daily Inspection
DIR - Director
DIST - Distance
DME – Distance Measuring Equipment
DNG - Danger or Dangerous
DNL - Day Night average sound Level(also Ldn)
DOC – Designated Operational Coverage
DOF - Date of Flight
DOP - Dilution of Precision
DP - Dewpoint Temperature, Deal Pending
DR – Dead Reckoning or Low Drifting(weather)
drms - Distance Root Mean Squared
DS - Duststorm
DSP - Departure Spacing Program
DTAM - Descend to and Maintain
DTK - Desired Track
DTRT - Deteriorate/Deteriorating
DTU - Data Transfer Unit
DU - Widespread Duststorm
DZ - Drizzle, Dropping Zone

E

E - Echo(phonetic alphabet), East
EA - Environmental Assessment
EAA - Experiemtal Aviation Authority
EAC - Expect Approach Clearance
EADI - Electrinic Altitude Director Indicator
EAS - Essential Air Service
EASA - European Aviation Safety Authority
EAT - Expected Approach Time
EATCHIP - European Air Traffic Control Harmonisation and Integration Programme
ECAC - European Civil Aviation Conference
ECAM - Electronic Centralised Aircraft Monitoring
ECOGAS - European Council of General Aviation Support
ECU - Environmental Control Unit
ED - Emergency Distance
EDCT - Expect Departure Clearance Time
E/E – Entry/Exit Lane
EET - Estimated Elapsed Time
EFAS - En-Route Flight Advisory Service, Electronic Flash Approach Light System
EFATO - Engine Failure At(or After) Take-Off
EFF - EFFective
EFIS – Electronic Flight Instrument Systems
EFM - En-Route Flow Management
EGT - Exhaust Gas Temperature
EHSI -Electronic Horizontal Situation Indicator
EIAR - Environmental Impact Assessment Report
EICAS - Engine Indicating and Crew Alerting System
EIR - Environmental Impact Report
EIS - Environmental Impact Statement
ELB – Emergency Locator Beacon
ELB-A - Emergency Locator Beacon - Aircraft
ELEV - Elevation
ELT – Emergency Locator Transmitter
ELR - Environmental Lapse Rate
EMBD - Embedded
EMERG - Emergency
ENE - East-Northeast
ENRT - En Route
EOF - Emergency Operations Facility
EOBT - Estimated Off-Block Time
EPA - Environmental Protection Agency
EPIRB – Emergency Position Indicating Radio Beacon
EPNdB - Effective Perceived Noise Decibel
EPNL - Effective Perceived Tone-Corrected Noise Decibel
epr - Engine Pressure Ratio
ERA - European Regional Airlines Association
ESE - East-Southeast
ESP - En-Route Spacing Program
EST - Estimate
ETA – Estimated Time of Arrival
ETD - Estimated Time of Departure
ETE - Estimated Time En-Route
ETI – Estimated Time Interval
ETMS - Enhanced Traffic Management System
ETN - Electronic Tandem Network
ETOPS - Extended Range Twin-Engine Operations(engines turn or passengers) EVCS - Electronic Voice Communications System
EVFR - Electronic Visual Fight Rules
F

F - Foxtrot(phonetic alphabet), Fahrenheit
FAA – Federal Aviation Administration (or Authority)
FAC - Facilities
FADEC - Full Authority Digital Engine Control
FAF - Final Approach Fix
FAL - Facilitation of International Air Transport
FAP - Final Approach Point
FAR - Federal Aviation Regulation
FAST -Final Approach Spacing Tool
FAT - Final Approach Track
FAWP - Final Approach Waypoint
FBO - Fixed Base Operator
FBU - Flight Briefing Unit
FBW - Fly-By-Wire
FC - Funnel Cloud(tornado or water-spout)
FCC - Federal Communications Commission (what Slim Shady refers to, I think) FCL – Flight Crew Licensing
FCM - Flight Confirmation Message
FCST -Forecast
FCU - Fuel Control Unit
FD – Flight Director
FDE - Fault Detection & Exclusion(GPS)
FDI – Flight Director Indicator
FDIO - Flight Data Input/Output
FDPS - Flight Data Processing System
FDR - Flight Data Recorder
FDS - Flight Director System
F&E - Facilities And Equipment
FE – Flight Examiner
FEIS - Final Environmental Impact Statement
FEMA - Federal Emergency Management Agency
FEW - Few Clouds
FF - Federal Finding
FFON - Flight Phone
FG -Fog
FI - Flight Instructor, Flight Identity(Mode S XPDR)
FIC - Flight Information Centre
FIE - Flight Instructor Examiner
FIR – Flight Information Region
FIS – Flight Information Service
FISA - Automated Flight Information Service (see also AFIS) FISO - Flight Information Service Officer
FL – Flight Level
FLIR - Forward-Looking Infra-Red
FLT - Flight(s)
FLTCK - Flight Check
FLUC - Fluctuating
FM - From(Weather), Frequency Modulation
FMA - Final Monitor Aid
FMCS - Flight Management Computer System
FMS - Flight Management System
FNPT - Flight and Navigation Procedures Trainer
FO - Forested Land
FOD - Foreign Object Damage
FOG - Fibre-Optic Gyro
FONSI - Finding of No Significant Impact
FPL - Full Performance Level, Flight Plan
FPM - Feet Per Minute
FPT - Flight Planned Track
FREH(D)A – Fuel, Radio, Engine, Heading(Direction), Altitude
FREQ - Frequency
FRQ - Frequent
FRTO(L) - Flight Radiotelephony Operator's License
FS - Flight Simulator
FSM - Flight Schedule Monitor
FSS - Flight Service Station
ft - Feet
FTD - Flight Training Device
ft/min - Feet Per Minute
FTO -Flying/Flight Training Organisation
FU - Smoke
FUA - Flexible Use Airspace
FW - Flight Watch
FWCS - Flight Watch Control Station
FZ - Freezing

G

G - Gusting, Golf(phonetic alphabet), Acceleration Force Unit, Green
GA - General Aviation
GA/AW - General Aviation/Aerial Work GAPAN - Guild of Air Pilots and Navigators
GAL - Gallons (US 3.78 litres, may be Imperial 4.54 liters) GAT - General Air Traffic
GC – Great Circle, Ground Control
GCA - Ground Controlled Approach
GCR - Ground Clutter Rejection
GDE - Ground Delay Enhancements
GEN - Generally(weather)
GEO - Geostationary Earth Orbit
GFT - General Flight Test
GLD - Glider
GLS - GPS Landing System
GLU - GNSS Landing Unit(CATIII)
GMC - Ground Movement Control
GMP - Ground Movement Planning
GMT – Greenwich Mean Time(now UTC)
GN - Green
GND - Ground
GNSS - Global Navigation Satellite System
GP - Glidepath
GPADIRS - Global Positioning Air Data Inertial Reference System
gph - Gallons Per Hour
GPS - Global Positioning System
GPU - Ground Power Unit
GPWS – Ground Proximity Warning System
GR - Hail, General Transport
GRADU - Gradual or Gradually
GS – Ground Speed, Glide Slope or Small Hail and/or snow pellets
G/S - Glideslope Receiver & Indicator
GSM - General Standard for Mobile Communications
GTOW - Gross Take-off Weight
GU - General Utility
GUMPS - Gas, Undercarriage, Mixture, Prop, Seatbelt
GVS - Gas Venting Site
GW - Gross Weight
GWDS - Graphic Weather Display System

H

H - High(Weather), Helicopter, Hotel(phonetic alphabet)
H24 - 24 Hours
HAA - Historic Aircraft Association
HAI - Helicopter Association International
HASELL – Height, Airframe, Security, Engine, Location Satisfactory, Look Out
HAT - Height Above Threshold(Jeppesen Approach Charts) HAZ MAT - Hazardous Materials
HBN - Hazard Beacon
HC - Hydrocarbons
HDG(C) – Heading Compass, actual heading on compass
HDG(M) – Heading Magnetic
HDT(T) – Heading True
HEL - Helicopter
HELPME - HEMS - Helicopter Emergency Medical Services
HEO - High-Earth Orbit
HF - High Frequency
Hg - Inches of Mercury(USA unit of atmospheric pressure)
HGT - Height or Height Above
HI - Heading Indicator
HIAL - High-Intensity Approach Lighting
HIGE - Hover In Ground Effect
HIRF - High-Intensity Radiated Fields
HIRL - High-Intensity Runway Lighting
HIRTA – High Intensity Radio Transmission Area
HISL - High-Intensity Strobe Lighting
HJ - Hours Jour(Day) i.e. Sunrise to Sunset
HLDG - Holding
HMI - Human Machine Interface
Hmr - Homer
HN - Hours Night i.e. Sunset to Sunrise
HNM - Helicopter Noise Model
HO - Hours of Operational Requirement
HOGE - Hover Out of Ground Effect
HOTAS - Hands on Throttle and Stick
HP - Horsepower, Holding Point
HPa – Hectopascal
HPA - High-Power Amplifier
HR - Hours
HS - Hours Scheduled i.e. During Scheduled Operations
HSI – Horizontal Situation Indicator
HT - Head of Training
HTA - Helicopter Training Area
HUD – Head-Up Display
HVY - Heavy
HX - Operating hours on request, no specific working hours
HZ - Dust Haze

I

I - Indigo(phonetic alphabet)
IAA – Irish Aviation Authority
IAC - Integrated Avionics Computer, Irish Aer Corps
IAF - Initial Approach Fix
IAP - Instrument Approach Procedure
IAPA - Instrument Approach Procedures Automation
IALPA - Irish Airline Pilot's Association
IAPS - Integrated Avionics Processing System
IAS – Indicated Airspeed
IATA - International Air Transport Association
IATSC - International Telecommunications Switching Centre
IAWP - Initial Approach Waypoint
IBn - Identification Beacon
I/C - Intercom IC - Ice Crystals
ICAA - International Civil Airports Association
ICAO – International Civil Aviation Organisation
ICE - Icing
ID/IDENT - Identification
IEM - Interpretative and Explanatory Manual
IF - Instrument Flying, Intermediate Approach Fix
IFR – Instrument Flight Rules
IFSS - International Flight Service Station
IG - Imperial Gallon
IGE - In Ground Effect
IGPH – Imperial Gallons Per Hour
IGS - Instrument Guidance System
ILS – Instrument Landing System
IM - Inner Marker
IMF - Internal Flow Management
IMC – Instrument Meteorological Conditions
IMES - Irish Marine Emergency Service
IMPR - Improving
IMSAFE - Illness, Medication, Stress, Alcohol, Fatigue, Emotion
IMT Immediately
in - inches (in aviation of mercury - unit of atmospheric pressure) INC - In Cloud
INCR - Increase/Increasing
INFO - Information
INOP - Inoperative
INS - Inertial Navigation System
INT - Intersection take-off, Interior
INTER - Intermittent(see TEMPO) INTSF - Intensify/Intensifying
IOAT - Indicated Outside Air Temperature
IOT - Input/Output Terminal
IPG - IFR Procedure Group
IR – Instrument Rating, Ice on Runway, Infra-Red
IRE - Instrument Rating Examiner
IRI - Instrument Rating Instructor
IRVR - Instrumented Runway Visual Range
ISA – International Standard Atmosphere
ISOL - Isolated
ISWL - Isolated Single Wheel Load
ITC - In-Trail Climb
ITD - In-Trail Descent
ITU - International Telephone Union(HF COM)
IU - Index Unit
IVSI – Instantaneous Vertical Speed Indicator

J

J - Juliet(phonetic alphabet)
JAA – Joint Aviation Authority
JAR – Joint Aviation Regulations/Recommendations/Requirement
JATO - Jet Assisted Take-Off
JB - Jet Barrier
JETA1 - Jet Turbine Fuel (same as AVTUR) JPATS - Joint Primary Aircraft Training System
JSA - Joint Steering Assembly
JURG - Joint User Requirement Group

K

K - Kilo(phonetic alphabet)
KCAS – Calibrated Airspeed (Knots)
Kg - Kilograms
kHz - Kilohertz(unit of frequency) KIAS – Indicated Airspeed (Knots)
km - Kilometre(unit of distance) KMH - Kilometres per hour
kPa - Kilopascal
KPAs - Key Performance Areas
kph - Kilometres Per Hour
KPI - Key Performance Indicator
KRAS – Rectified Airspeed (Knots)
kt - Knot(unit of speed, 1.852km/h)
KTAS - Knots True Air Speed
kw - Kilowatt

L

L - Low (Weather), Lima(phonetic alphabet), Lift, Locator, Left
LAHSO - Land and Hold Short Operation
LAMAX - A-Level Maximum (noise metric)
LAMS - Light Aircraft Maintenance Schedule
LAN - Inland
LARS – Lower Airspace Radar Service
LAT - Latitude
LATCC - London Air Traffic Control Centre
LAWRS - Limited Aviation Weather Reporting Station
LC - Local Control
LCD - Liquid Crystal Display
Lctr - Locator Beacon(NDB)
LD – Landing Distance
L:D – Lift/Drag Ratio(also L/D)
LDA – Landing Distance Available, Localizer Directional Aid
LDG - Landing
LDIN - Lead-In LIghts
LDN - Day-Night Average Sound Level(also DNL)
LEO - Low-Earth Orbit
LEPN - Symbol for EPNL - perceived sound exposure level(dB)
LEQ - Equivalent Sound Level
LF – Low Frequency
LFA - Local Flying Area
LGT - Light/Lighting
LH - Left-Hand
LIRL - Low-Intensity Runway Lights
LIRS - Low-Impact Resistance Supports
LITAS - Low-Intensity Two-Colour Approach System
LLZ - Localizer
LLWAS - Low-Level Windshear Alert System
LMB - Light Marker Beacon
LMT – Local Mean Time
LNAV - Lateral Navigation(GLS)
LOA, LoA - Letter of Agreement
LOC - Location, Locally, Localizer
LOFT - Line-Oriented Flight Training
LOM - Locator Outer Marker
LONG - Longitude
LoP - Line of Position
LORAN - Long-Range Air Navigation System
LRR - Long-Range Radar
LRT - Long-Range Fuel Tanks
LRU - Line Replaceable Unit
LSQ - Line Squall
LTFC - Landing Traffic
LT - Local Time
LTE - Long-Term Exception
LTO - Landing and Take-Off cycle
LUG - Land Use Guidance
LV - Light and Variable(wind)
LW - Landing Weight
LYR - Layer/Layered

M

M - Mike(phonetic alphabet), Minus, Magnetic, Metres
MAD - Mean Aerodynamic Chord
MAHWP - Missed Approach Holding Waypoint
MALS - Medium-Intensity Approach Lighting System
MALSF - Medium-Intensity Approach Lighting System with sequenced Flashers
MALSR - Medium-Intensity Approach Lighting System with Runway alignment indicator lighting system
MAP - Missed Approach Procedure/Point, Manifold Pressure, Aeronautical Maps/Charts
MAPT - Missed Approach Point
MARAS - Middle Airspace Radar Advisory Service
MATSE - Meeting(ECAC Ministers) on the Air Traffic System in Europe
MATZ - Military Aerodrome Traffic Zone
MAUW - Maximum All-Up Weight
MAWP - Missed Approach Waypoint
mb - Millibars
MBRW - Maximum Brake Release Weight
MCA - Magnesium Calcium Acetate
MCC - Multi-Crew Cooperation/Certificate
MCI - Mobile Communication Infrastructure
MCP - Maximum Continuous Power
MCTR - Military Control Zone
MCU - Minimum Configuration Unit
MDA - Minimum Descent Altitude
MDA(H) - Combination of MDA & MDH(Jeppesen Approach Charts)
MDAU - Maintenance Data Acquistion Unit
MDH - Minimum Descent Height, Major Damage History
ME - Multi-Engine
MEA - Minimum En-Route IFR Altitude
MEDA - Military Emergency Diversion Airfield
MEF – Maximum Elevation Figures
MEHT - Minimum Eye-Height over Threshold(VASI/PAPI)
MEL - Minimum Equipment List
MEO - Medium Earth Orbit
MEP -Multi-Engine Piston
MET - Multi-Engine Turboprop, Meteorology(ical)
METAR - METeorological Actual Reports(current weather)
METFAX - METeorological Faxing Service
METO - Maximum Except for Take-Off
MF – Medium Frequency
MFA - Military Flying Area
MFD - Multi-Function Display
MGD - Million Gallons per Day
MGW - Maximum Gross Weight
MH – Magnetic Heading
MHA - Minimum Holding Altitude
MHz - Megahertz
MI - Shallow
MIL - Military
MINIT - Minutes-In-Trail
MIRL - Medium-Intensity Runway LIghts
MIS - Meteorlogical Impact Statement
MIST - Meteorological Information Self-briefing Terminal
MIT - Miles-In-Trail
MKR - Marker radio beacon
MLS - Microwave Landing System
MLW - Maximum Landing Weight
MM- Middle Marker
MMI - Man-Machine Interface(see HMI)
MMR - Multi-Mode Receiver
MN – Magnetic North
MNM - Minimum
MNPS - Minimum Navigational Performance Specifications
MOA - Military Operations Area
MOCA - Minimum Obstacle Clearance System
MOD - Moderate
MOGAS - Motor Gasoline (not same as used in cars etc.)
MOH - Major Overhaul
MON - Motor Octane Number(aviation fuel rating)
MOPS - Minimum Operational Performance Standard(RTCA)
MOS - Military Operations Specialist
MOTNE - Meteorological Operational Telecommunications Network Europe
MP - Manifold Pressure, Multi-Pilot
MPA - Multi-Pilot Aeroplane, Man-Powered Aircraft
mph - Miles Per Hour
MPH - Multi-Pilot Helicopter
MRO - Maintenance, Repair & Overhaul
MRVA - Minimum Radar Vector Altitude
MRW - Maximum Ramp Weight
MS - Minus
MSA - Minimum Safe Altitude, Minimum Sector Altitude(Jeppesen Approach Charts)
MSG - Message
MSP - Maintenance Service Program
MT - Mountain, Magnetic Track
MTBF - Mean Time Between Failures
MTI – Moving Target Indicator
MTMA - Military Terminal Control Area
MTOM - Maximum Take-Off Mass
MTOW - Maximum Take-Off Weight
MTW - Mountain Waves
MTWA - Maximum Total Weight Authorised(AAIU)
MVA - Minimum Vectoring Altitude
MZFW - Maximum Zero Fuel Weight

N

N - November(phonetic alphabet), No Change, North, Night
NAA - National Aviation Authority(generic term inside JAA)
NADP - Noise Abatement Departure Profile
NAS - National Airspace System
NAT - North Atlantic Track
NATS - National Air Traffic Service(UK)
NAV - Navigation
NAVAID - Navigation Aid
NC - No Change
NDB – Non-Directional Beacon
NDB(L) - NDB(Localizer)
NE - Northeast
NEF - Noise Exposure Forecast
NEM - Noise Exposure Map
NEXRAD - Next Generation Radar
NGT - Night
NIL - Nothing, No Information
NIMBY - Not In My Back Yard
NIPAH - Name, Intentions, Position, Altitude, Heading(Mayday Call) NLR - Noise Level Reduction
NM – Nautical Miles
NMS - Navigation Management System
NMU - Navigation Management Unit
NNE - North-Northeast
NNW - North-Northwest
NO2 - National Oceanic Service
NOAA - National Oceanic and Atmospheric Administration
NOE - Nap of Earth
NORAD - North American Aerospace Defense Command
NORDO - No Radio
NOSIG - No Significant Change
NOTAM – Notices to Airmen
NOTAMC - Cancelled Notices to Airmen
NOTAMN - New Notices to Airmen
NOTAMR - Replaced Notices to Airmen
NOTAR - No Tail Rotor
NOX - Nitrogen Oxide
NPA - Non-Precision Approach, Notice of Proposed Amendment
NPD - Noise-Power-Distance
NPO - Non-Profit Organisation
NPPL - National Private Pilot's License
NPRL - No Parallel
NPRM - Notice of Proposed Rule Making(USA)
Ns(or NS) - Nimbostratus
NSC - No Significant Cloud
NSW - Nil Significant Weather
NTSB - National Transportation Safety Board(USA)
NTZ - No Transgression Zone
NVM - Non-Volatile Memory
NW - Northwest
NWS - National Weather Service

O

O - Oscar(phonetic alphabet)
O&D - Origination and Destination
O&M - Operations and Maintenance
OAC - Oceanic Area Control Unit
OAG - Official Airline Guide
OALT - Operational Acceptable Levels of traffic
OAT – Outside Air Temperature, Operational Air Traffic(MIL)
OBI – Omni Bearing Indicator
OBS – Omni Bearing Selector, Observed
OBSC - Obscured
OBST - Obstacle, Obstruction
OCA - Oceanic Control Area, Obstacle Clearance Altitude
OCA(H) - Combination of OCA & OCH(Jeppesen Approach Charts)
OCH - Obstacle Clearance height
OCL - Obstacle Clearance Limit
OCNL - Occasional
ODALS - Omnidirectional Airport Lighting System
OEM - Original Equipment Manufacturer
OFA - Object-Free Area
OFZ - Object-Free Zone
OH - Overhaul
oktas - unit equivalent to one eighth of the sky(describes cloud cover)
OM - Outer Marker
OML - Operational Multicrew Limitation
OMS - Outer-Marker Substitute(virtual kind of OM)
ONC – Operational Navigational Chart
ONUS – Overshoot on North, Undershoot on South (Southern Hemisphere only)
OPMET - Operational Meteorological(Information)
OPS - Operations, Operating Hours
O/R - On Request
OSL - Operational Safety Pilot Limitation
O/T - Other Times
OTD - Other Training Devices
OVC - Overcast
OVF - Overflight Operation
OXY - Oxygen

P

P - Papa(phonetic alphabet), Plus, Prohibited Area, Primary Frequency
P’s & T’s – Pressures and Temperatures
PA - Passenger Address
PACE - Program for Airport Capacity Efficiency
PANS - Procedures for Air Navigation Services
PAPIS - Precision Approach Path Indicating System
PAR - Precision Approach Radar PART - Pressure-Altitude Reporting Transponder
PAT – Power, Attitude, Trim
PATSA - Power, Attitude, Trim, Sense, Adjust
PAX - Passengers
PBH - Power By the Hour(Rolls-Royce)
PC - Positive Control(Mooney)
PCL - Pilot Controlled Lighting>(RWY controlled by Microphone)
PCS - Power Conditioning System
PCU - Power Control Unit
PDC - Pre-Departure Clearance
PE - Ice Pellets
PEC - Position Error Correction
PED - Personal Electronic Devices(Walkmans etc.)
PEP - Peak Envelope Power
PERM - Permanent
PF – Pilot Flying
PFA - Popular Flying Association
PFC - Passenger Facility Charge
PHACER - Position, Heading, Altitude, Conditions, Estimate, Request
PHARE - Programme for Harmonisation of ATM Research in EUROCONTROL
PIAC - Peak Instantaneous Aircraft Count
PIC – Pilot In Command
PICUS - Pilot In Command Under Supervision
PIO - Pilot Induced Oscillation
PIREP - Pilot Reports
Pitot - Total Pressure
PL – Position Line
PLN - Flight Plan
PM - Particulate Matter
PMS - Performance Management System (Unless of course you're female!)
PNdB - Percieved Noise Decibel
PN - Prior Notice
PNF – Pilot Not Flying
PNLTM - Perceived Noise Level Tone-Corrected Maximum
PNR – Prior Notice Required, Point of No Return
PNT - Paint
PO - Dust/Sand Whirls(Dust Devils)
POB - Passengers on Board
POH - Pilot's Operating Handbook
PPI – Plan Position Indicator
PPL – Private Pilot’s License
PPO - Prior Permission Only
PPR – Prior Permission Required
PR - Partial
PRK - Photo Refractory Keratomy(eye surgery)
PRM - Precision Runway Marker
PROB - Probability Factor
PROV - Provisional
PS - Plus
psi - Pounds per Square Inch
PSN - Position
PTN - Procedure Turn
PTT - Press to Transmit/Talk
PTLE - Position, Time, Level, Estimated time to next position
PUF – Propeller, Pitch, Undercarriage, Flaps
PVT - Private
PY - Spray

Q

Q - Quebec(phonetic alphabet), QNH
QATS - Quality Assurance and Training Specialist
QBI - Compulsory IFR Flight
QDM – Magenetic bearing to a NDB
QDR – Magnetic bearing from a NDB
QFE – Height above aerodrome level (Field Elevation)
QFI - Qualified Flying Instructor
QFU - Magnetic Orientation of Runway
QGH - Ground interpreted let-down procedure using direction-finding equipment
QGO - Airport Closed
QNE - Pressure Height(1013.2 mb or hPa)
QNH – MSL pressure level in the actual atmosphere(ALT gives height AMSL)
QoS - Quality of Service
QTE – True magnetic bearing to a NDB
Qts. – Quarts(oil)

R

R - Romeo(phonetic alphabet), Runway, Restricted, Right, Red, Radial
R&D - Research and Development
RA - Rain, Radio Altitude, Resolution Advisory
RAA - Regional Airline Association
RAC - Rules of the air and air traffic services
RAD - Radar
RADAR – Radio Detection And Ranging
RAG -Ragged
RAILS - Runway Aligned Indicator Lighting System
RAIM - Receiver Autonomous Integrity Monitoring
RALT - Regardless of Altitude
RAPID - Rapidly
RAS – Rectified Airspeed or Radar Advisory Service
RB – Relative Bearing
RBI – Relative Bearing Indicator, Runway Bearing Indicator
RCA - Recommended Crossing Altitude, Radio Corporation of America
RCC – Rescue Coordination Centre
RCL - Runway Centreline
RCLS - Runway Centreline Light System
RCU - Radio Control Unit
RDH - Reference Datum Height(for ILS)
RDL - Radial
RDO - Radio
RDPS - Radar Data Processing System
RE - Recent
REA - Ready Message
REC – Receiver
REIL - Runway End Identification Lights
REM – Rapid Eye Movement
REP - Reporting Point or Report
REQ - Request or Requested
RF – Royal Flight, Radio Frequency, Registered Facility
RFU - Radio Frequency Unit
RG - Retractable Gear
RH - Relative Humidity, Right Hand
Rho – Air Density
RIS - Radar Information Service
RL – Rhumb Line
RMI – Radio Magnetic Indicator
RMK - Remarks
RMU - Radio Management Unit
RNAV – Area(Regional) Navigation
RNC – Radio Navigation Charts
RNP - Radio Navigation Plan, Required Navigation Performance
RNSS - Radio Navigation Satellite Services
ROC - Regional Operations Centre
RoC – Rate of Climb
ROD - Record of Decision
RoD – Rate of Descent
RODA - Regardless of Destination Airport
ROFA - Runway Object-Free Area
ROFOR - Route Forecast
RON - Remain Overnight, Research Octane Number(Auto Fuel Rating)
RPL - Repetitive Flight Plan
RPM - Revolutions Per Minute
RPZ - Runway Protection Zone
RQ - Indication of a request
RRTE - Re-Route
RSA - Runway Safety Area
RSC - Rescue sub-centre
RSL - Runway Status Light
RSTN -Restriction(s)
RSU - Runway Supervispry Unit
R/T – Radio Transceiver, Radiotelephony
RTD - Delayed(MET) RTF - Radiotelephony
RTO - Rejected Take-Off
RT/R - Remote Transmitter/Receiver
RVR - Runway Visual Range
RVSM - Reduced Vertical Seperation Minima(1000ft above FL290)
RVV - Runway Visibility Value
R/W - Runway
Rwy – Runway
Rx - Receive
RxTx - Receiver/Transmitter
S

S - Sierra(phonetic alphabet), South, Wing Surface Area, Secondary Frequency
SA - Sandstorm, Duststorm, Rising Dust or Rising Sand
SAC - Strategic Air Command
SAAC - Society of Amateur Aircraft Constructors
SAE - Society of Automotive Engineers
SAFEPILOT - Sensibly loaded, airspeed maintained, fuel checked, enough runway, properly planned, in practice, learns from others, obtained weather, thorough lookout
SAFI - Semi-Automatic Flight Inspection
SAL - Supplementary Approach Lighting
SALR - Saturated Adiabatic Lapse Rate
SALS - Simple Approach Lighting System
SAP - Soon as Possible
SAR – Search And Rescue
SARBE - SAR Beacon
SARP - Standard and Recommended Practices
SAS - Stability Augmentation System
SAT - Satellite
SATNAV - Satellite Naviagtion(generic)
SATCO - Senior Air Traffic Control Officer
SB - Service Bulletin
SBAC - Society of British Aerospace Companies
SBY – Standby
Sc(or SC) - Stratocumulus
SCATANA - Security Control of Air Traffic and Navigational
SCT - Scattered
Sctr - Sector
SDAU - Safety Data Analysis Unit(of the CAA)
SDU - Satellite Data Unit
SE - Single-Engine, Systems Enigineer, Southeast

SECRA - Secondary Radar
SEL - Sound Exposure Level, Single-Engine Land
SELCAL - Selective Calling System on HF Radio
SEP - Single Engine Piston
SET - Single-Engine Turboprop
SEV - Severe
SFC - Surface, Specific Fuel Consumption
SFE - Synthetic Flight Examiner
SFI - Synthetic Flight Instructor
SG – Specific Gravity, Snow Grains
SGL - Signal
SH - Showers
SHP - Shaft Horsepower
SI - Surveillance Identity(Mode S XPDR), Statutory Instrument

SIC - Second-In-Command
SID - Standard Instrument Departure
SIGMET - Significant Meteorological Service(hazardous weather warning)
SIGWX - Significant Weather
SIM - Simulator
SIMUL - Simultaneous/Simultaneously
SIRO - Simultaneous Intersecting Runway Operation
SKC - Sky Clear
SL – Sea Level
SLMG - Self-Launching Motor Gider
SLP - Speed Limit Point
SM – Statute Miles
SMEL - Single/Multi Engine Land
SMOH - Since Major Overhaul
SMPI - Since Major Periodic Inspection
SMR - Surface Movement Radar
SN - Snow, Serial Number
SNOCLO - Closure of airport due to snow
SNOWTAM - Snow Notam SO - Southern Reporter
SO2 - Sulphur Dioxide
SOL - Safety of Life
SOP – Standard Operating Procedure
SP - Single Pilot
SPA - Single-Pilot Aeroplane
SPCC - Spill Prevention Control and Countermeasure SPECI - Special Weather Report(in code)
SPECIAL - Special Weather Report(in plain language)
SPH - Single-Pilot Helicopter
SPIC - Student Pilot-in-Command
SPIFR - Single-Pilot IFR
SPOH - Since Propeller Overhaul
SPOT - Spot Wind
SQ - Squall
SR - Service Road, Sunrise
SRA - Surveillance Radar Approach, Special Rules Area
SRE - Surveillance Radar Element(PAR)
SRZ - Special Rules Zone
SS - Sandstorm, Sunset
SSA - Sector Safe Altitude(Aerad Approach Charts)
SSB - Single Sideband
SSCVR - Solid State Cockpit Voice Recorder
SSE - South-Southeast
SSR – Standard Stall Recovery, Secondary Surveillance Radar
SST - Supersonic Transport
SSW - South-Southwest
St(or ST) - Stratus
STA - Scheduled Time of Arrival
STAR - Standard Terminal Arrival Route
STC - Supplemental Type Certificate, Sensitivity Time Compensation
STD - Synthetic Training Device, Scheduled Time of Departure
STF - Stratiform
STNR - Stationary
STOL - Short Take-Off and Landing
SVCBL - Serviceable
SVFR - Special Visual Flight Rules
SUA - Special Use Airspace
SW - Shortwave, Southwest
SWAP - Severe Weather Avoidance Plan
SWC - Significant Weather Chart

T

T - Tango(phonetic alphabet), Temperature, Thrust
TA - Time-Above (noise metric), Transition Altitude
TACT - Tactical Flow Management Working Position
TACAN – Tactical Air Navigation Aid(MIL)
TAF - Terminal Area Forecast(weather forecast)
TAI – International Atomic Time
TAR - Terminal Area Surveillance Radar
TAS – True Airspeed
TB - Transit Bearing
TBO - Time Between Overhaul TC – Turn Coordinator, True Course
TCA - Terminal Control Area
TCAS – Traffic Collision & Avoidance System
TCH - Threshold Crossing Height
TCU - Towering Cumulus
TDC - Top Dead Centre
TDD - Telecommunications Devices for the Deaf
TDME - Terminal DME
TDO - Tornado
TDWR - Terminal Doppler Weather Radar
TDZ - Touchdown Zone
TDZE - Touchdown Zone Elevation(Jeppesen Approach Charts)
TDZL - Touchdown Zone Lights
TE – Track Error
TEMPO - Temporary Change
TEND - Tend /Tending to
TERPs - Thermal Insrument Procedures
TGL - Touch-and-go landing
TGO - Touch-and-Go Operation
TGS - Taxiing Guidance System
TGT - Turbine Gas Temperature
TH - True Heading
THLD - Threshold
THR - Threshold
TKE - Track Error(also TE)
TKOF - Take-Off TL - Until(Weather) TLS - Transponder Landing System
TM - Traffic Management
TMA – Terminal Manoeuvring Area
TMC - Traffic Management Coordinator
TMF - Traffic Management Function
TMG – Track Made Good or Touring Motor Glider
TMPFISCH – Trim/Throttle Friction Nut, Mixture, Primer, Fuel/Flaps, Instruments, Switches, Controls/Carb/Cowl Flaps, Hatches/Harness/Hydraulics(pre-flight take-off checks)
TMS - Traffic Management System
TMU - Traffic Management Unit
TN - True North
TNA - Thermal Neutron Analysis(or Activator)
TNC - Tactical Navigation Chart
TNW – Temporary Navigational Warning Information Bulletin
T/O - Take-Off TOC - Top of climb
TOD - Take-off distance
TODA – Take-Off Distance Available
TOP- Cloud top
TOR - Take-off run
TORA – Take-Off Run Available
TOSS - Take-Off Safety Speed
TOW - Take-Off Weight
TP - Turning Point
TPC - Tactical Plotting Cahrt
TPHP - Typical Peak Hour Passengers
TR – Track, Type Rating, Total Reaction
T/R - Thrust Reversers
TRACAB - Terminal Radar Approach Control in Tower Cab
TRACON - Terminal Radar Approach Control
TRE - Type Rating Examiner
TREND - Weather changes expected in 2 hours (Landing Forecast)
TR - Type-Rating
TRANSCEIVER - Transmitter-Receiver
TRANSPONDER - Transmitter-Responder
TRE - Type-Rating Examiner
TRI - Type Rating Instructor
TRSA - Terminal Radar Service Area
TRTO - Type Rating Training Organisation
TS - Thunderstorm
TSC - Time Since CORE
TSMO - Time Since Major Overhaul
TSN - Time Since New
TSO - Technical Standard Order
TST – Test
TT - Total Time, True Track
TTG - Time-to-go
TTS – Time-to-Station
TTSN - Total Time Since New(same as TSN)
TTW - Time-to-Waypoint
TUC – Time of Useful Consciousness
TURB - Turbulence
TVOR - Terminal VOR
TWEB - Transcribed Weather Broadcast
TWR - Tower
TWY - Taxiway
TWYL - Taxiway link
Tx - Transmit
TX - Transponder
TYP - Type of aircraft
TYRO - Lacking Experience (military)

U

U - Uniform(phonetic alphabet), Increasing
UA - Air Report(PIREP) UAC - Upper Area Control Centre
UAR - Upper air route
UAV - Unmanned Aerial Vehicle UFN - Until Further Notice
UFO - Unidentified Flying Object
UHF - Ultra-High Frequency(military only)
UIR – Upper flight information region
UL - Ultralight
UNL - Unlimited
UNOS – Undershoot on North, Overshoot on South (Northern Hemisphere only)
UP - Unknown Precipitation
U/S - Unserviceable
USG – US Gallons
UTC – Coordinated Universal Time
UWB - Ultra-Wide Band
UV - Ultraviolet

V

V - Varying, Victor(phonetic alphabet), Velocity(TAS)
V1 - Critical Engine Failure Velocity(Takeoff Decision Speed)
V2 - Take-Off Climb Velocity
VAor VMAN – Manoeuvring Speed(maximum structural speed allowed for full control deflection)
VA - Volcanic Ash
VAC - Volts AC
VAD - Visual Approach/Departure
VAL - In Valleys, Visual Approach and Landing(Chart)
VAR – Variation
VASI(S) – Visual Approach Slope Indicator System
VAT - Nominal Speed at Threshold
VB - Turbulence Penetration Speed
VC - Vicinity of Aerodrome
VCY - Vicinity
VDMaximum Dive Speed(for certifiaction only)
VDC - Volts DC
VDF – Very High Frequency Direction Finding
VER - Vertical
VFE – Maximum Speed Flaps Extended(down)
VFR – Visual Flight Rules
VHF – Very High Frequency
VHF-COM – Radio Transceiver (R/T)
VHF-COM/NAV – Combined Radio & Navigation Receiver
VHF-NAV - Navigation Radio
VIP - Very Important Person
VIS - Visual, Visibility
VLA - Very Light Aircraft
VLE - Maximum Speed Landing Gear Extended
VLF – Very Low Frequency
VLO – Maximum Speed Landing Gear Operation(extending or retracting)
VMC – Visual Meteorological Conditions
VMH - Visual Manoeuvring Height
V-n - Velocity/Load
VNAV - Vertical Navigation(GLS)
VNE – Speed Never Exceed
VNO – Speed Normal Maximum, (maximum structural cruising speed
VOLMET - In-flight Meteorological Service(Latin Volens-Flying)
VOR – Very High Frequency Omni-Directional Radio Range
VOR/DME - Combined VOR/DME Station
VOT - VOR airborne equipment test facility
VORTAC - VOR and TACAN combination(MIL)
VRRotation Speed
VRA - Rough Air Airspeed
VRB - Variable
VRP – Visual Reference Point
VSB – VHF Survival Beacon
VSI – Vertical Speed Indicator
VS0 – Stall speed gear & flaps down
VS1 – Stall speed ‘clean’ i.e. flaps up, gear up(if retractable)
VSSE - Minimum Safe Single Engine Speed
V/STOL - Vertical or Short Take-Off and Landing
VTOL - Vertical Take-Off and Landing
VTURB - Turbulence Penetration Speed(a.k.a. VB) VV/// - Cloud base not discernible, state of sky obscured
VX – Speed setting maximum angle in a climb
VXSE - Speed setting maximum angle in a climb, 1 engine inoperative
VY – Best vertical speed in a climb
VYSE - Best vertical speed in a climb, 1 engine inoperative

W

W - Whiskey(phonetic alphabet), West, Weight, White
WAC – World Aeronautical Chart
WAAS - Wide-Area Augmentation System(GNSS)
WAT - Weight, Altitude, Temperature
WC - Weather Coordinator
WCA – Wind Correction Angle
WDSPR - Widespread
WEF - With effect from or effective from
WGS - World Geodesic System
WIE - With immediate effect or effective immediately
WILCO - Will Comply
WIP - Work In Progress
WKN - Weakening
WMO - World Meteor WNW - West-Northwest
WOSSSSS – Wind, Obstacles, Size/Shape of field, Surface/Slope, Shoots, Sun, S(c)ivilisation
WP - Waypoint
WPT - Waypoint
WRDA - Weapons Range Danger Area
WRNG - Warning
WS - Windshear
WSFO - Weather Service Forecast Officer
WSO - Weather Service Office
WSW - West-Southwest
W/V – Wind Velocity
Wx - Weather

X

X - X-Ray(phonetic alphabet), Heavy(MET e.g. XXRA - heavy rain)
XC - Cross-country
XPDR - Transponder
XPOND - Transponder
XTK - Cross Track, Cross Track Error
Y

Y - Yankee(phonetic alphabet)
YD - Yaw Damper

Z

Z - Zulu(phonetic alphabet), a.k.a. UTC
ZAC – Zenith Aircraft Company
ZFW - Zero Fuel Weight

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