Radio Abbreviations

A list of all used radio abbreviations


Abbreviation Term
AAE above aerodrome elevation
AAL above aerodrome level
A/C aircraft
ACARS Aircraft Communication and Addressing Reporting System
ACAS airborne collision avoidance system
ACC active clearance control
ACFT aircraft
ACI Airports Council International
ACMS aircraft condition monitoring system
ACU air condition unit
AD airworthiness directive
A/D aerodrome
ADA advisory area
ADAHRS air data attitude heading reference system
ADC air data computer
ADD acceptable deferred defect
ADF automatic direction finder
ADI Attitude Director Indicator
ADIRS Air Data Inertial Reference System
ADIZ Air Defense Identification Zone
ADS automatic dependent surveillance
AFCS automatic flight control system
A/FD Airport/Facility Directory
AFDS autopilot flight director system
AFE above field elevation
AFS aeronautical fixed service
AFT Aft The direction against the aircraft movement
AFTN Aeronautical Fixed Telecommunication Network
AGL above ground level
AHRS Attitude and heading reference system
AIP Aeronautical Information Publication
AIRAC Aeronautical information regulation and control
ALI Airworthiness Limitation Item
ALS approach lighting system
AMO Approved Maintenance Organization
AMSL above mean sea level
ANSP air navigation service provider
AOA angle of attack
AOC air operator’s certificate
AOG aircraft on ground
AP autopilot
A/P airplane (US), aeroplane (ICAO)
APT airport
APU auxiliary power unit
AR authorization required
ARINC Aeronautical Radio Inc.
ARP aerodrome reference point
ARTCC air route traffic control centers
ASAS Airborne Separation Assurance System
ASI airspeed indicator
ASL above sea level
ASM airspace management
A/T autothrottle
ATA Air Transport Association
ATC air traffic control
ATFM air traffic flow management
ATIS Automatic Terminal Information Service
ATM air traffic management
ATN Aeronautical Telecommunication Network
ATQP Alternative Training and Qualification Programme
ATPL Airline Transport Pilot Licence
ATS air traffic service


Abbreviation Term
BC back course
BITE Built-In Test Equipment
BL Butt Line
B/P Blue Print
BPR bypass ratio
BOM Bill of Material
BWC bird watch condition


Abbreviation Term
C2 command and control
CAA Civil Aviation Authority
CAR civil aviation requirements
CAS calibrated airspeed
CDI course deviation indicator
CDU control/display unit
CFIT controlled flight into terrain
CG center of gravity
CTR controlled traffic region/control zone


Abbreviation Term
EAS equivalent airspeed
EASA European Aviation Safety Agency
EBOM engineering Bill of Material
ECAM electronic centralised aircraft monitor
ECET end of civil evening twilight
ECR Engineering Change Request
EDTO extended diversion time operations
EFB electronic flight bag
EFIS electronic flight instrument system
EGT exhaust gas temperature
EICAS engine-indicating and crew-alerting system
E-LSA experimental light-sport aircraft
ELT emergency locator transmitter
EMAS engineered materials arresting system
EOBT estimated off-blocktime
EPR engine pressure ratio
ESA emergency safe altitude
ETA estimated time of arrival
ETD estimated time of departure
ETOPS Extended-range Twin-engine Operation Performance Standards, see ETOPS
EUROCAE European Organisation for Civil Aviation Equipment
EW Empty Weight


Abbreviation Term
FIR flight information region
FL flight level


Abbreviation Term
GA general aviation
G/A or GA go-around
GCA Ground-controlled approach
GEA Ground effect area
GLOC g-induced loss of consciousness, where g is acceleration relevant to the acceleration caused by gravity
GND ground
GP glide path. See Instrument landing system
GPS Global Positioning System
GPU Ground Power Unit
GPWS ground proximity warning system
G/S glideslope
GS groundspeed
GSE ground support equipment


Abbreviation Term
H Heavy (in the context of wake turbulence categories)
H High
HAZMAT Hazardous Material
HDG Heading
HFE Human Factors Engineering[2]
HFES Human Factors and Ergonomics Society
HIRO High Intensity Runway Operation
HIRTA High Intensity Radio Transmission Area
HIWAS Hazardous Inflight Weather Advisory Service
HL Height loss
HLD hold (hold altitude or speed or something else) (same as maintain, but not maintenance!)
HPA human-powered aircraft
HSI horizontal situation indicator
HUD head-up display
HUM Human Remains
HW headwind
HYD hydraulic
HYDIM hydraulic interface module


Abbreviation Term
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
ICD Interface Control Document
ICO idle cut-off
IDT identify (XPDR)
IEPR integrated engine pressure ratio
IF intermediate approach fix
IFA International Federation of Airworthiness
IFATCA International Federation of Air Traffic Controllers’ Associations
IFE In Flight Entertainment
IFR instrument flight rules
IFSD in-flight shutdown
ILS instrument landing system
IMC instrument meteorological conditions
IML Inside Mold Line
INS inertial navigation system
IR Initial Release
IRS inertial reference system
IRT instrument rating test
ISA International Standard Atmosphere
ISFD integrated standby flight display
ISIS integrated standby instrument system
ITAR International Traffic in Arms Regulations
ITT interstage turbine temperature
IAW In accordance with


Abbreviation Term
KCAS knots calibrated airspeed
KIAS knots indicated airspeed
KTAS knots true airspeed


Abbreviation Term
L Light (in the context of wake turbulence categories)
LAME licensed aircraft maintenance engineer
LCC low-cost carrier
LCG load classification group
LCN load classification number
LHO live human organs
LIR Loading Instruction Report
LKP last known position
LLC Life Limited Component
LLZ localizer (ILS)
LM land and marine
LOC loss of control; localizer
LOFT line-oriented flight training
LOTC loss of thrust control
LNAV lateral navigation
LPV localizer performance with vertical guidance
LRU line-replaceable unit
LSAS longitudinal stability augmentation system
LTP Landing Threshold Point
LW Landing Weight
LOM Limitation Of Movement


Abbreviation Term
M Medium (in the context of wake turbulence categories)
MAC mean aerodynamic chord
MAP missed approach point
MATS Manual of Air Traffic Services
MCP mode control panel
ME Manufacturing Engineer
MEA Minimum En-route Altitude
MCDU Multi control display unit
MDA minimum descent altitude
MDH minimum descent height
MEDEVAC medical evacuation
MEF maximum elevation figure
MMEL master minimum equipment list
MEL minimum equipment list
METAR meteorological aerodrome report (METAR)
MFD multi function display
MLDW maximum landing weight
MLS microwave landing system
MM middle marker
MOC minimum obstacle clearance
MOCA Minimum Obstruction Clearance Altitude
MORA Minimum Off Route Altitude
MP manifold pressure
MRB Material Review Board
MRO maintenance repair overhaul
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
MZFW maximum zero-fuel weight


Abbreviation Term
NADP Noise Abatement Departure Procedure
NDB Non-directional beacon
NDT Non-destructive testing
NOTAM notice to airmen
NTZ No-transgression zone


Abbreviation Term
OBE overcome by events
OBS omni-bearing selector
OCA obstacle clearance altitude
OCH obstacle clearance height
OEI one engine inoperative
OEM original equipment manufacturer
OIS obstacle identification surface
OM outer marker
OTS out of service
OW operational weight


Abbreviation Term
P (as a prefix:) prohibited airspace
PA pressure altitude
PANS-OPS procedures for air navigation services – aircraft operations
PAPI precision approach path indicator
PAOG Pre Aircraft on Ground
PAR precision approach radar
PAX passenger
PBD place bearing distance (RNAV waypoint)
PCN pavement classification number
PDG procedure design gradient
PDAS public domain aeronautical software
PET point of equal time
PF pilot flying
PFD primary flight display
PFAF precision final approach fix
PIC Pilot In Command
PICUS Pilot In Command, under supervision[3]
PIO Pilot Induced Oscillations
PIP performance improvement package
PIREP Pilot Report
PJE Parachute jumping exercise
PM pilot monitoring
PNF pilot not flying
PNR Point of No Return
POA Production Organisation Approval
POH Pilot’s Operating Handbook
POF Principles Of Flight
PPL private pilot licence
PPR prior permission required
PSR point of safe return
PSR power supply reset
PSU personal service unit
PS Pax Step
PTT push to talk


Abbreviation Term
QFE the Q-code for: Atmospheric pressure at aerodrome elevation (or at runway threshold)
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
R (as a prefix:) restricted airspace
RA radio altitude or radar altimeter
RA resolution advisory (in the context of TCAS)
RAS rectified air speed
RA(T) restricted area (temporary)
RAT ram air turbine
RCO remote communications outlet
RDH reference datum height for ILS
RESA runway end safety area
RFI recreational flight instructor
RNAV area navigation
RNP required navigation performance
RSA runway safety area
RSR en-route surveillance radar
RT radiotelephony
RTO rejected take-off
RTOW regulatory take-off weight
RVR runway visual range
RVSM reduced vertical separation minima
RWY runway
RW ramp weight
RPL Repetitive Flight Planning


Abbreviation Term
SAS stability augmentation system
SCAP Standard Computerized Airplane Performance
SESAR Single European Sky ATM Research
SIGMET Significant Meteorological Information
SMOH Since major overhaul
SMR surface movement radar
SOC start of climb at missed approach
SOP standard operating procedure
SOW Statement of Work
SID standard instrument departure
SR sunrise
SS sunset
STC supplemental type certificate
STAR standard terminal arrival route
SODPRO simultaneous opposite direction parallel runway operations


Abbreviation Term
TA traffic advisory (see TCAS)
TAA terminal arrival area
TACAN tactical air navigation
TAF terminal aerodrome forecast
TAM total airport management
TAR terminal approach radar
TAS true airspeed
TAT total air temperature
TAWS terrain awareness and warning system
TCA terminal control area
TCAS traffic collision avoidance system
TCH threshold crossing height
TDZ touchdown zone
TERPS terminal procedures
TFC traffic
TFR temporary flight restriction
TGB transfer gearbox
TGL temporary guidance leaflet
THLD threshold
THR runway threshold
THS trimmable horizontal stabilizer, see tailplane
TLD time-limited dispatch
TMA terminal manoeuvring area (Europe)/terminal control area (USA and Canada)
TMZ transponder mandatory zone
TOD top of descent
TODA take-off distance available
TO/GA take-off/go around
TOR take-off runway
TORA take-off runway available
TOW take-off weight
TOWS take-off warning system
TP turning point at missed approach
TRA temporary reserved area (airspace)
TRACON terminal radar approach control
TRP thrust rating panel
TSO technical service order
TTAF total time air frame
TTSN total time since new
TTSO total time since overhaul
TWR tower
TWY taxiway


Abbreviation Term
UAS Unmanned Aircraft System[4]
UAV unmanned air vehicle
UHF ultra-high frequency
UIR upper information region
UTC Universal Time Coordinated


Abbreviation Term
V&V Video & Vision[5]
VASI visual approach slope indicator
VDP Visual descent point
VFR visual flight rules
VHF very high frequency
VMC visual meteorological conditions
VNAV vertical navigation
VOR VHF omnidirectional range
VSI Vertical speed indicator
VVI Vertical velocity indicator (the same as VSI)

V speeds

Abbreviation Term
V1 speed at or above which takeoff cannot be safely interrupted
Va maneuvering speed
Vfe maximum flaps extended speed
Vle maximum landing gear extension sp
Vlo maximum landing gear operating 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
Vs stall speed
Vso stall speed in landing configuration
Vx best angle of climb speed
Vy best rate of climb speed


Abbreviation Term
WAT weight, altitude, temperature: variables that affect takeoff performance
W&B Weight & Balance
WEF with effect from
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


Abbreviation Term
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