List of aviation, aerospace and aeronautical abbreviations

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This is a list of aviation, aerospace, aeronautical and avionics abbreviations.


Abbreviation Term Note
A/A Air to air TACAN function
A/C aircraft[1]
A/D aerodrome
A/F autofeather
A/FD Airport/Facility Directory
A/P Autopilot
AAE above aerodrome elevation[1] In aviation, above aerodrome level (AAL), or above aerodrome elevation (AAE), denotes that an altitude is given above the nearest aerodrome or airport.
AAIB Air Accidents Investigation Branch United Kingdom
AAIM Aircraft Autonomous Integrity Monitoring
AAO assumed adverse obstacle
AAS airport advisory service[1]
AC advisory circular[2] Information and guidance publication
ACAM aircraft continuous airworthiness monitoring
ACARS Aircraft Communication and Addressing Reporting System
ACAS airborne collision avoidance system
ACC area control centre[1]
ACC active clearance control Turbine engine system
ACC Accessory In gas turbine engine
ACE Actuator control electronics
ACFT aircraft
ACI Airports Council International
ACM air cycle machine Part of A/C air conditioning system
ACMS aircraft condition monitoring system
ACP Audio Control Panel
ACR Avionic Communication Router
ACS1 Airman Certification Standards[3] FAA pilot testing
ACS2 Audio control system
ACU1 air condition unit
ACU2 alternator control unit[2] Protection from alternator over-voltage.
AD airworthiness directive
ADA advisory area
ADAHRS air data attitude heading reference system
ADC air data computer
ADD acceptable deferred defect
ADF automatic direction finder Navigation equipment
ADI Attitude Director Indicator
ADIRS Air Data Inertial Reference System
ADIRU Air Data Inertial Reference Unit
ADIZ Air Defense Identification Zone
ADJ Adjustment Mechanical term
ADM1 aeronautical decision-making Piloting term of judgment
ADM2 air data module
ADS1 air data system
ADS2 automatic dependent surveillance
ADS-A Automatic dependent surveillance – address
ADS-B Automatic dependent surveillance – broadcast
ADS-C Automatic dependent surveillance – contract
ADV Arbeitsgemeinschaft Deutscher Verkehrsflughäfen "German Airports Association"
AEA Association of European Airlines
AESA Active electronically scanned array
AFCS automatic flight control system
AFD autopilot flight director
AFDC autopilot flight director computer
AFDS autopilot flight director system
AFDX Avionics Full-Duplex Switched Ethernet
AFE above field elevation
AFIS airborne flight information system also called automatic flight information service
AFM aircraft flight manual
AFS aeronautical fixed service
AFT Aft The direction against the aircraft movement
AFTN Aeronautical Fixed Telecommunication Network
AGACS Automatic ground–air communications system also known as ATCSS or data link
AGB accessory gear box mainly used in turbine engine
AGC automatic gain control
AGDL air–ground data link
AGL above ground level
AHC attitude heading control
AHRS Attitude and heading reference system
AIDS aircraft integrated data system
AIM Aeronautical Information Manual
AIP Aeronautical Information Publication
AIRAC aeronautical information regulation and control
AIRMET Airmen's Meteorological Advisory[4] in-flight advisory given over 126.7
AIXM aeronautical information exchange model
ALI Airworthiness Limitation Item
ALS approach lighting system
ALT Altitude
ALT Alternate
ALUM Aluminum
AND Aircraft Nose Down
AMC Acceptable Means of Compliance (EASA)
AME Aircraft Maintenance Engineer
AME Aviation Medical Examiner
AMM Aircraft Maintenance Manual
AMO Approved Maintenance Organization
AMSL above mean sea level
AMP aircraft maintenance program
AMT Aircraft Maintenance Technician
ANSP air navigation service provider
ANSP Authorization of Aircraft Network Security Program (FAA)
ANPT Aeronautical national pipe taper
ANSOG Airport Network Security Operator Guidance (Boeing)
A/O Air oil In turbine engines
AOA angle of attack
AOC air operator's certificate
AOG aircraft on ground
AOM aircraft operations manual
AOM airport/aerodrome operating minima
AP autopilot
A/P airplane (US), aeroplane (ICAO)
APP Appendix
APPL Application
APPROX Approximately
APT airport
APU auxiliary power unit
APV approach procedure with vertical guidance
AR airworthiness review
AR authorization required
AR As required
ARC airworthiness review certificate
ARINC Aeronautical Radio Inc.
ARO airport reservation office
ARP aerodrome reference point
ARTCC air route traffic control centers
ASAS Airborne Separation Assurance System
ASDA Accelerate Stop Distance Available
ASI airspeed indicator
ASL above sea level[1]
ASLO Aircraft Security Logging Overview
ASM airspace management
ASM available seat miles
assy assembly
A/S Anti-Skid
A/T autothrottle
A/THR Autothrust
ATA Air Transport Association
ATC air traffic control
ATD actual time of departure equivalent to off-block time[5]
ATF aerodrome traffic frequency
ATFM air traffic flow management
ATIS Automatic Terminal Information Service
ATM Air traffic management
ATN Aeronautical Telecommunication Network
ATO Approved Training Organisation
ATPL Airline Transport Pilot Licence
ATQP Alternative Training and Qualification Programme
ATS air traffic service
AVAIL available
AWBS Aviation weather briefing service[4] Available at designated FSS's
AWG American Wire Gage The larger the size number, the smaller the wire diameter.
AWIS Aviation weather information service[4] Available at FSS
AWOS Automated weather observation system[4] Automated METAR reporting system
AWWS Aviation weather web site[6] In Canada


Abbreviation Term Note
BC back course
BCAA Belgian Civil Aviation Authority
BDC bottom dead centre[1] Piston engine
BFL balanced field length
BHP brake horsepower[1]
BITE Built-In Test Equipment
BL Butt Line
BME Bridge Mounted Equipment
B/P Blue Print
BPR bypass ratio
BOM bill of material
BTV Brake-to-Vacate System A new feature introduced by Airbus A380
BWC bird watch condition
BVID Barely Visible Impact Damage
BVR Beyond Visual Range


Abbreviation Term Note
C2 command and control
CA Captain
CAA Civil Aviation Authority
CAM cockpit area microphone Part of a cockpit voice recorder
CAME Continuing Airworthiness Management Exposition
CAMO Continuing Airworthiness Management Organisation
CAMP Continuous Airworthiness Maintenance Program (FAA)
CANSO Civil Air Navigation Services Organisation
CAP cabin attendant panel
CAR civil aviation regulation
CARs civil aviation regulations[7][8]
CARS Canadian Aviation Regulations
CAS calibrated airspeed
CASS Commercial Air Service Standards
CASS continuing analysis and surveillance system
CAT clear air turbulence[1]
CAT Commercial Air Transport
CAW continuing airworthiness (EASA)
CBT computer based training
CCRs closed circuit mixed gas rebreathers
CCRs constant current regulators
CDCCL critical design configuration control limitation
CDI course deviation indicator
CDL configuration deviation list
CDU control/display unit
CFIT controlled flight into terrain
CFG constant frequency generator
CFR Code of Federal Regulations
CG center of gravity
CH Course Heading
CHDO certificate-holding district office (FAA)
CHT Cylinder Head Temperature (Piston engine aviation)
CI cost index
CL check list a flight deck manual
CMC central maintenance computer
CMM component maintenance manual
CMO Certificate Management Office FAA
CMV converted meteorological visibility
CMPA complex motor-powered aircraft
CofA Certificate of airworthiness
COTS Commercial off-the-shelf
CPDLC controller–pilot data link communications
CPR Changed product rule EASA
CRD Comment-response document (EASA) Part of rule making process
CRES Corrosion resistant steel
CS certification specification (EASA)
CSD constant speed drive
CSO cycles since overhaul
CSS cabin services system
CSU constant speed unit
CSCT Configuration Item Signer Crater Tool Boeing
CTAF common traffic advisory frequency
CTR controlled traffic region/control zone
CVR cockpit voice recorder
CWS control wheel steering


Abbreviation Term Note
D Compass Deviation
DA density altitude
DA/H decision altitude/height (rel. to THR) See instrument landing system
DAH design approval holder (EASA)
DBER damaged beyond economic repair
DER departure end of runway
DER Designated Engineering Representative
DEU display electronic unit
DG directional gyro
DGPS differential GPS[1]
DGR Dangerous Goods Regulation
DIA diameter
DLR German Aerospace Center / Deutsches Zentrum für Luft- und Raumfahrt e.V.
DME distance measuring equipment
DME Designated Mechanic Examiner[2] A person appointed by the FAA
DMI deferred maintenance item
DO design organization
DOA design organization approval EASA
DOM design organization manual
DODAR diagnose, options, decide, act/assign, review
DOW dry operational weight
DP Departure Procedures
DR dead reckoning
DTO declared training organisation
DUATS Direct User Access Terminal Service


Abbreviation Term
EA engineering authorisation
EADI Electronic Attitude Direction Indicator
EAS equivalent airspeed[1]
EASA European Aviation Safety Agency
EAT expected approach time[1]
EBOM engineering Bill of Material
EBU engine build-up
EC engineering control (also E/C)
ECAM electronic centralised aircraft monitor
ECET end of civil evening twilight
ECR Engineering Change Request
ECS Environmental control system
EDR engineering data record
EDTO extended diversion time operations
EEC electronic engine control
EET estimated elapsed time
EFB electronic flight bag
EFC expect further clearance
EFFRA engine failure flap retraction altitude
EFIS electronic flight instrument system
EFP engine failure procedure
EFS elevator feel shift
EFTO engine failure on take-off
EGPWS enhanced ground proximity warning system
EGT exhaust gas temperature
EHM engine health monitoring
EHSI Electronic Horizontal Situation Indicator
EICAS engine-indicating and crew-alerting system
E-LSA experimental light-sport aircraft
ELAC elevator and aileron computer
ELOS Equivalent Level of Safety
ELT emergency locator transmitter
EMAS engineered materials arresting system
EMDP electric motor driven pump
ENCASIA European Network of Civil Aviation Safety Investigation Authorities
EOBT estimated off-blocktime
EPA European part approval (EASA)
EPR engine pressure ratio
ERM engineering request for maintenance
ESA emergency safe altitude
ETA estimated time of arrival
ETD estimated time of departure[1]
ETE estimated time en route[1]
ETL effective translational lift
ETOPS Extended-range Twin-engine Operation Performance Standards, see ETOPS
ETSO European Technical Standard Order, issued by EASA; see TSO
EUROCAE European Organisation for Civil Aviation Equipment
EVAS emergency vision assurance system
EW Empty Weight


Abbreviation Term Note
FAA U.S. Department of Transportations' Federal Aviation Administration Organisation
FADEC full authority digital engine control Engine equipment
FAC Flight Augmentation computer Avionics
FAF final approach fix
FAF [first available flight] Airline operations
FANS future air navigation system Avionics
FAP final approach point
FAP forward attendant panel Aircraft equipment
FAR Federal Aviation Regulation FAA regulation
FAR/AIM Federal Aviation Regulation /
Aeronautical Information Manual
bundle of FAA regulations and Aeronautical Manual[9]
FAROS final approach runway occupancy signal
FATO final approach and take off
FB Winds aloft World Meteorological Organization abbrev. see also FD
FBO fixed-base operator Airfield operations
FBS fixed base simulator Flight crew training
FBW fly-by-wire
FC flight crew
FCF functional flight check Check functionality after maintenance
FCOM flight crew operating manual Aircraft operations
FCTM flight crew training manual
FCU fuel control unit In turbine engines
FD flight director Avionics
FD upper winds and temperature forecast[1] US and Canada abbrev. See also FB
FDM flight data monitoring Operations planning
FDR flight data recorder (also known as black box) Avionics
FDTL flight duty time limitations
FEP final end point
FFDZ free fall drop zone (parachutists)
FFS full flight simulator Flight crew training
FIC flight information centre
FIDO Fog Investigation and Dispersal Operation Airfield operations
FIKI Flight Into Known Icing Aircraft operations
FIR flight information region ATC
FIS Federal Inspection Services
FISE flight information service enroute
FL flight level ATC
FM frequency modulation Example: FM immunity
FMA flight mode annunciator Equipment
FMC flight management computer (part of a FMS) Avionics
FMGC flight Management and guidance computer Avionics
FMS flight management system Avionics
F/O First Officer Flight crew
FOD foreign object damage Airfield operations
FOO flight operation officer Person
FOQA flight operational quality assurance
FPA flight path angle
FPL filed flight plan ATC
FPM feet per minute
FSDO Flight Standards District Office (FAA)
FSF Flight Safety Foundation Organisation
FSIMS Flight Standards Information Management System (FAA)
FSS flight service station
FTD flight training device Flight crew training
FTL flight time limitations
FVU flux valve unit Equipment


Abbreviation Term Note
GA general aviation
G/A or GA go-around aborted landing procedure
GBST ground-based, software tool airfield operations
GCA Ground-controlled approach airfield operations
GCU generator control unit
GEA Ground effect area
GLOC g-induced loss of consciousness "g" is acceleration relevant to the acceleration caused by gravity
GM guidance material (EASA)
GMM general maintenance manual
GND ground airfield operations
GP glide path see instrument landing system
GPP general practices and procedures
GPS Global Positioning System avionics
GPU Ground Power Unit Aerospace Ground Equipment
GPWS ground proximity warning system avionics
G/S glideslope avionics
GS groundspeed
GSE ground support equipment aerospace ground equipment
GUMPS Gas, Undercarriage, Mixture, Propeller, Seat belts/Switches mental checklist before landing


Abbreviation Term Note
H Heavy (in the context of wake turbulence categories)
H High
HAT Height Above Touchdown
HAZMAT Hazardous Material
HBCS High Bandwidth Connectivity System
HDG Heading Navigation
HDI Horizontal Deviation Indicator
HFE Human Factors Engineering[10]
HFES Human Factors and Ergonomics Society
HIGE Hover In Ground Effect
HIRL High Intensity Runway lighting Airfield operations
HIRO High Intensity Runway Operation Airfield operations
HIRTA High Intensity Radio Transmission Area
HIWAS Hazardous Inflight Weather Advisory Service
HL Height loss
HLD hold Maintain same altitude or speed or direction
HMG hydraulic motor generator
HMU hydro-mechanical unit In turbine engine
HOGE Hover Out of Ground Effect Helicopter operations
HPA human-powered aircraft Aircraft type
HPC high pressure compressor In turbine engine
HPT high pressure turbine In turbine engines
HPTACC high pressure turbine active clearance control Mainly used in turbofan engines
HSI horizontal situation indicator Avionics
HUD head-up display Avionics
HUM Human Remains
HW headwind
HYD hydraulic Aircraft equipment
HYDIM hydraulic interface module


Abbreviation Term Note
IB Inboard
IAC instrument approach chart
IAF initial approach fix
IAP instrument approach procedure
IAS indicated airspeed
IATA International Air Transport Association
ICA Instructions for Continuous Airworthiness
ICAO International Civil Aviation Organization
ICAS International Council of the Aeronautical Sciences
ICD Interface Control Document
ICO idle cut-off
ICTS Ice Contaminated Tailplane Stall
IDG integrated drive generator Combination of a CSD and generator in a single case
IDT identify (XPDR)
IEPR integrated engine pressure ratio
IETM interactive electronic technical manual
IF intermediate approach fix
IFA International Federation of Airworthiness
IFATCA International Federation of Air Traffic Controllers' Associations
IFE In Flight Entertainment
IFP instrument flight procedure
IFR instrument flight rules
IFSD in-flight shutdown
IGV Inlet guide vane
ILS instrument landing system
IMC instrument meteorological conditions
IML Inside Mold Line
IPC Illustrated Parts Catalog (e.g. by Boeing, Airbus)
IR Initial Release
IRS inertial reference system
IRT instrument rating test
IRVR instrumented runway visual range
ISA International Standard Atmosphere
ISFD integrated standby flight display
ISIS integrated standby instrument system
ITAR International Traffic in Arms Regulations
ITT interstage turbine temperature


Abbreviation Term
JAA Joint Aviation Authorities
JAR Joint Aviation Requirements


Abbreviation Term
KCAS knots calibrated airspeed
KIAS knots indicated airspeed
KRE key risk element
KTAS knots true airspeed


Abbreviation Term Note
L Light in the context of wake turbulence categories
LAHSO Land And Hold Short Operations
LAME licensed aircraft maintenance engineer
LCC low-cost carrier
LCG load classification group
LCN load classification number
LDA landing distance available
LDA localizer type directional aid
LHO live human organs
LIR Loading Instruction Report
LKP last known position
LLC Life Limited Component
LLP Life Limited Part EASA, ICAO
LLZ localizer (ILS)
LM land and marine
LNAV lateral navigation
LOA letter of authorization FAA
LOC loss of control; localizer
LOFT line-oriented flight training
LOM limitation of movement
LOM locator outer marker
LOTC loss of thrust control
LPC low pressure compressor In turbine engines
LPT low pressure turbine
LPTACC low pressure turbine active clearance control Mainly used in turbofan engines
LPV localizer performance with vertical guidance
LRC long range cruise
LRU line-replaceable unit
LSAP loadable software aircraft part (EASA) introduced in RMP for technical records
LSAS longitudinal stability augmentation system
LTC line training captain
LTP landing threshold point
LVP low visibility procedures
LW landing weight
LZ landing zone


Abbreviation Term
M medium (in the context of wake turbulence categories)
MAC mean aerodynamic chord
MAC mid-air collision
MAP missed approach point or manifold absolute pressure
MATS Manual of Air Traffic Services
MBC Main Base Check
MCAS Maneuvering Characteristics Augmentation System
MCC Multi Crew Coordination
MCDU multifunction control display unit
MCH Manufacturer Certificate Holder (TCCA); see also PAH and POA
MCP mode control panel
MCT maximum continuous thrust
MCDU multi control display unit
MDA minimum descent altitude
MDDR maintenance deferred defect record
MDH minimum descent height
MDM multi-disciplinary measure (EASA)
ME Manufacturing Engineer
MEA Minimum En-route Altitude
MEDEVAC medical evacuation
MEF maximum elevation figure
MMEL master minimum equipment list
MEL minimum equipment list
MEP multi-engine piston
METAR meteorological aerodrome report (METAR)
MFD multi-function display
MFRA minimum flap retraction altitude
MH magnetic heading
ML maintenance laptop
MLDW maximum landing weight
MLG Main Landing Gear
MLS microwave landing system
MM middle marker
MOCA Minimum Obstacle Clearance Altitude
MOE maintenance organisation exposition
MORA Minimum Off Route Altitude
MP manifold pressure
MPL multi-crew pilot license
MRB Material Review Board
MRO maintenance, repair, overhaul
MRO maintenance and repair organization
MROT Minimum Runway Occupancy Time
MRP Material Resources Planning
MRW maximum ramp weight
MSA minimum safe altitude / minimum sector altitude
MSDS Material Safety Data Sheet
MSL mean sea level
MSLW Max. Structural Landing Weight
MSTOW Max. Structural Take-off Weight
MTOW maximum take-off weight
MSZFW Max. Structural Zero Fuel Weight
MVA Minimum Vectoring Altitude
MX Maintenance
MZFW maximum zero-fuel weight


Abbreviation Term Note
NADP noise abatement departure procedure
NDB non-directional beacon
NDT non-destructive testing
NGS nitrogen generation system
NHA next higher assembly
NIST National Institute of Standards and Technology
NLG nose landing gear
NLR Netherlands Aerospace Research Centre
NNC non-normal checklist
NORDO no radio
NOTAM notice to airmen
NOTAR no tail rotor[2] helicopter control system
NPA non-precision approach
NPA notice of proposed amendment (EASA)
NPRM notice of proposed rulemaking (FAA)
NRR noise reduction rating hearing protector attenuation
NRTC nonroutine task card
NTZ no-transgression zone

N numbers (turbines)[edit]

Abbreviation Term Note
N compressor speed[1] N1, N2, etc. refers to specific compressor spool (in the order that air passes over them).
Ng gas generator speed[1]
Nh high rotor speed[1]
Np power turbine speed[1]
Nr rotor speed (helicopters) Np and Nr are typically shown on the same gauge with two needles, both expressed in percent, so that the pilot can tell if the power turbine is driving the rotor or if it is freewheeling.


Abbreviation Term
OAT outside air temperature
OBE overcome by events
OBS omni-bearing selector
OCA obstacle clearance altitude
OCCM on condition / condition monitored components
OCH obstacle clearance height
OEI one engine inoperative
OEM original equipment manufacturer
OGV outlet guide vane
OHM overhaul manual
OIS obstacle identification surface
OM outer marker
OML outer mold line
ONS onboard network system
ONAT Onboard Network Access Terminal
OTS out of service
OPC operational check
OPS/CHK operational check
OW operational weight


PJA || Parachute Jumping Area
Abbreviation Term
P (as a prefix:) prohibited airspace
PA pressure altitude
PAH production approval holder (FAA); see also POA and MCH
PANS-OPS procedures for air navigation services – aircraft operations
PAOG Pre Aircraft on Ground
PAPI precision approach path indicator
PAR precision approach radar
PATWAS Pilot's Automatic Telephone Weather Answering Service[4]
PAX passenger
PBCS performance-based communication and surveillance
PBD place bearing distance (RNAV waypoint)
PBE Protective Breathing Equipment
PBN Performance-Based Navigation
PC proficiency check
PCN pavement classification number
PDA performance degradation allowance
PDAS public domain aeronautical software
PDG procedure design gradient
PDM pilot decision making
PDU power drive unit (flap actuation)
PET point of equal time
PF pilot flying
PFAF precision final approach fix
PFD primary flight display
PIC Pilot In Command
PICUS Pilot In Command, under supervision[11]
PIO Pilot Induced Oscillations
PIP performance improvement package
PIREP Pilot Report
PJE Parachute jumping exercise
PM pilot monitoring
PMA Parts Manufacturer Approval
PMG Permanent magnet generator
PN part number (also P/N)
PNF pilot not flying
PNR Point of No Return
POA Production Organisation Approval (EASA); see also PAH and MHC
POB persons on board
POF Principles Of Flight
POH Pilot's Operating Handbook
PPL private pilot licence
PPR prior permission required
PS passenger step
PSR point of safe return
PSR power supply reset
PSR primary surveillance radar
PSU passenger service unit
PTCU power transfer Control unit
PTF permit to fly
PTT push to talk
PYLD payload


Abbreviation Term
QAR quick access recorder
QCM quality and compliance monitoring
QEC quick engine change
QFE the Q-code for: Atmospheric pressure at aerodrome elevation (or at runway threshold)
QNE the Q-code for pressure altitude
QNH the Q-code for: Altimeter sub-scale setting to obtain elevation when on the ground, i.e. altitude above MSL
QRA quick reaction alert
QRH quick reference handbook


Abbreviation Term Note
R (as a prefix:) restricted airspace
RA radio altitude or radar altimeter
RA resolution advisory (in the context of TCAS)
RAAS Runway Awareness and Advisory System
RAAS remote airport advisory service
RAIM Receiver Autonomous Integrity Monitoring
RAREPS Weather Radar Reports[4] Provided by Air Traffic Controllers
RAS rectified air speed
RA(T) restricted area (temporary)
RAT ram air turbine
RCO remote communications outlet
RDH reference datum height for ILS
REO Repair engineering order
RFF rescue and fire fighting
RFI recreational flight instructor
RGB reduction gear box
RIA regulatory impact assessment (EASA)
RII required inspection items
RMI radio magnetic indicator
RMP Radio Management Panel
RMT rule making task (EASA)
RNAV area navigation
RNP required navigation performance
RPL Recreational Pilot Licence
RPL repetitive flight planning
RPT regular public transport
RQR Required
RSA runway safety area
RSR en-route surveillance radar
RT radiotelephony
RTB return to base
RTF radiotelephony
RTL rudder travel limiting
RTO rejected take-off
RTOW regulatory take-off weight
RVDT rotary variable differential transformer In a turbine engine
RVR runway visual range
RVSM reduced vertical separation minima
RW ramp weight
RWY runway


Abbreviation Term
SAR Surveillance Approach Radar
SAS stability augmentation system
SAT Saturated Air Temperature
SB service bulletin
SC special condition
SCAP Standard Computerized Airplane Performance
SCCM senior cabin crew member
SDF Simplified directional facility
SEP Safety and Emergency Procedures
SEP single-engine piston
SESAR Single European Sky ATM Research
SESMA Special Event Search and Master Analysis
SFCC Slat Flap Control Computer
SFO Senior First Officer
SFOC Special Flight Operating Certificate
SID standard instrument departure
SIGMET Significant Meteorological Information
SLPC single lever power control
SM service manual
SMM safety management document (ICAO)
SMOH Since major overhaul
SMR surface movement radar
SMT software maintenance tool
SN serial number
SOC start of climb at missed approach
SODPRO simultaneous opposite direction parallel runway operations
SOG speed over ground (same as ground speed)
SOP standard operating procedure
SOW Statement of Work
SR sunrise
SRM structural repair manual
SS sunset
STAR standard terminal arrival route
STC supplemental type certificate
STOL short take-off and landing[1]
STS speed trim system
SVFR Special visual flight rules


Abbreviation Term Note
TA traffic advisory (see TCAS)
TAA terminal arrival area
TAC thrust asymmetry compensation
TACAN tactical air navigation
TAF terminal aerodrome forecast
TAI thermal anti-ice
TAM total airport management
TAR terminal approach radar
TAS true airspeed
TAT total air temperature
TAWS terrain awareness and warning system
TBO time between overhauls
TBV transient bleed valve In turbine engines
TC towering cumulus
TC turn coordinator
TC True Course
TC type certificate
TCA terminal control area
TCAS traffic collision avoidance system
TCCA Transport Canada's Civil Aviation
TCDS type certificate data sheet
TCH threshold crossing height
TCI thrust computer indicator
TCU terminal control unit Air traffic control
TDZ touchdown zone
TERPS terminal procedures
TFC traffic
TFR temporary flight restriction Airspace
TGB transfer gearbox
TGL temporary guidance leaflet
TGL(S) touch-and-go landing(s)
THLD threshold
TH True Heading
THR runway threshold
THS trimmable horizontal stabilizer, see tailplane
TIT turbine inlet temperature
TLD time-limited dispatch
TLB technical logbook (EASA)
TLS transponder landing system
TMA terminal manoeuvring area (Europe)/terminal control area (USA and Canada)
TMG touring motor glider
TML Toolbox Mobile Library (Boeing)
TMZ transponder mandatory zone
TOC Top of Climb (also known as T/C)
TOD top of descent
TODA take-off distance available
TO/GA take-off/go around
TOP take-off power
TOR take-off runway
TORA take-off runway available
TOW take-off weight
TOWS take-off warning system
TR transformer rectifier
TR thrust reversers
TP turning point at missed approach
TRA temporary reserved area (airspace)
TRACON terminal radar approach control
TRE type rating examiner
TRP thrust rating panel
TSO technical standard order[2] FAA specification of quality standard.
TTAF total time air frame
TTSN total time since new
TTSO total time since overhaul
TWB Transcribed Weather Broadcasts[4] Abbreviated area forecast
TWC tail wind component
TWLU Terminal Wireless LAN Unit
TWR tower
TWY taxiway


Abbreviation Term Note
UAS Unmanned Aircraft System[12]
UAV unmanned air vehicle commonly called 'drones'
UHF ultra-high frequency
UIR upper information region
UTC Universal Time Coordinated indicates time zones


Abbreviation Term Note
V magnetic variation
V&V video & vision[13]
VASI visual approach slope indicator
VBV variable bleed valve in turbine engines
VCR visual control room
VCS vehicle control service
VDP visual descent point
VFR visual flight rules
VG vortex generator
VGM voice generator module see AWOS
VHF very high frequency
VID visible impact damage
VIGV variable inlet guide vane
VMC visual meteorological conditions
VNAV vertical navigation
VNC VFR navigation chart
VOR VHF omni-directional range
VRS vortex ring state helicopter flight phenomenon
VSCF variable speed constant frequency electricity generation system
VSI vertical speed indicator
VSV variable stator vane in a turbine engine
VTA VFR terminal area chart[1]
VTOL vertical take-off and landing[1]
VVI vertical velocity indicator same as VSI

V speeds[edit]

Abbreviation Term
V1 speed at or above which takeoff cannot be safely interrupted
V2 speed at or above which takeoff can be done with 1 engine out
Va maneuvering speed
Vfe maximum flaps extended speed
Vle maximum landing gear extension speed
Vlo maximum landing gear operating speed
Vlof lift-off speed
Vmc minimum control speed
Vmca velocity of minimum control in the air
Vmcg velocity of minimum control on ground
Vmo maximum operating speed
Vne never-exceed speed
Vno normal operating speed limit
Vr rotate speed
Vra rough air speed
Vref reference touchdown speed
Vs stall speed
Vso stall speed in landing configuration
Vx best angle of climb speed
Vy best rate of climb speed


Abbreviation Term
WAC World Aeronautical Chart
WAT weight, altitude, temperature: variables that affect takeoff performance
W&B Weight & Balance
WCA Wind Correction Angle
WDM Wiring Diagram Manual
WEF with effect from
WOCL window of circadian low
WOFW weight-off-wheels, indicates aircraft is off ground since lift off
WONW weight-on-wheels, indicates aircraft is on ground since touch down
WS wind shear
WTC Wake Turbulence Category
Wx weather[1]


Abbreviation Term
XC cross-country[1]
XMIT transmit
XPDR transponder
XPNDR transponder


Abbreviation Term
Y yaw or yaw angle
Y/D yaw damper


Abbreviation Term
Z Zulu Time (UTC)
ZFT zero-fuel time
ZFW zero-fuel weight
ZULU Zulu Time (UTC)

See also[edit]


  1. ^ a b c d e f g h i j k l m n o p q r s t u v w McDonald, Sandy A.F. From the ground up. Aviation Publishers Co. Ltd. pp. Appendix B.
  2. ^ a b c d e Jeppesen, Boeing. A&P Technician General Textbook. pp. Glossary.
  3. ^ [1]
  4. ^ a b c d e f g Nielsen, Dane. PILOT PREP. Canuck West Holdings Inc.
  5. ^ "Actual Off-Block Time - EUROCONTROL ATM Lexicon". Retrieved 2019-03-12.
  6. ^ "AWWS – Forecasts and Observations". Retrieved 2017-04-06.
  7. ^
  8. ^
  9. ^ "FAR/AIM Series". Aviation Supplies & Academics, Inc.
  10. ^
  11. ^ "Training requirements". Civil Aviation Authority (UK).
  12. ^ US DoD
  13. ^


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