List of abbreviations

  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

Abbreviation	Meaning(s)	Description
A	At or Above (constraint altitute)
A	Autotuning
AAR	Air-to-air refuelling
ACARS	Aircraft Communications Addressing and Reporting System	A digital datalink system for transmission of short, relatively simple messages between aircraft and ground stations via radio or satellite
ACAWS	Advisory, Caution And Warning System.	A system which monitors the aircraft's systems and provides warning messages to the crew (similar to EICAS).
ACCEL HT	Acceleration Height
ACT	Active
A/C	Aircraft
ACC	Area control centre
ADC	Air Data Computer
ADF	Automatic direction finder	tuned to NDB
ADIRS	Air Data Inertial Reference System
ADIRU	Air Data Intertial Reference Unit
AFCS	Automatic Flight Control System
AFDS	Auto Pilot Flight Director System
AGL	Above Ground Level	AGL
ALS	Approach lighting system
ALT	Altitude	Altitude
ALT NAV	Alternate Navigation
AMI	Airline Modifiable Information
AMSL	Above mean sea level
AoA	Angle of Attack	The angle of the (nose of the) aircraft relative to the surrounding airflow (Pitch is relative to the ground)
AIMS	Airplane Infromation Management System
AIP	Aeronautical Information Publication
APP	Approach	Used for autopilots among other.
Apt Elev	Airport Elevation	the MSL of a central point of an airport
APU	Auxiliary power unit	Primary purpose is to provide power to start the main engines
A/P	Autopilot
ARINC	Aeronautical Radio, Incorporated
ASCPC	Air Supply and Cabin Pressure Controllers
ASEL	Airplane, Single Engine, Land certificate	A particular class rating associated with a pilots certification.
ASES	Airplane, Single Engine, Sea certificate	A particular class rating associated with a pilots certification.
ASOS	Automated Surface Observation System	measures and broadcasts surface wheather info automatically
AT	AT (an altitude)
ATA	Actual Time of Arrival
ATC	Air Traffic Control
ATIS	Automatic Terminal Information Service
ATM	Air traffic management	Integrated management of air traffic and airspace. Can include ATC, ATS, flow management etc. through seamless collaboration with involved parties.
ATS	Air traffic service	A generic term that can mean flight information service, alerting service, air traffic advisory service or air traffic control service.
ATT	Attitude
ATZ	Aerodrome Traffic Zone
A/T	Autothrottle	A/P Subsystem which controls the throttle
AWACS	Airborne Warning And Control System

B

Abbreviation	Meaning(s)	Description
B	At or Below (constrained altitude)
BC	Back course	part of ILS, beacon that provides range information, like OM/MM/IM, specifies FAF for back course, a back course is non-precison since no G/S associated
BITE	Built-In Test Equipment
BRG/DIS	Bearing and/or Distance
BRT	Brightness

C

Abbreviation	Meaning(s)	Description
C	Celsius (Centigrade)
CALC	Calculated
CANC	Cancel
CDI	Course Deviation Indicator	part of a VOR gauge, a needle showing whether you are on course (centered) or not (left or right)
CDU	Control Display Unit
CG	Center of Gravity
CI	Cost Index
CLB	Climb
CLB DIR	Climb Direct
CLR	Clear
CMCF	Central Maintenance Computer Function
CO DATA	Company Data
COMM	Communications
CON	Continuous
CRS	Course
CRT	Cathode Ray Tube
CRZ	Cruise
CRZ ALT	Cruise Altitude
CRZ CG	Cruise Center of Gravity
CRZ CLB	Cruise Climb
CTAF	Common Traffic Advisory Frequency	Available at airfields with no operational control tower.
CTC	Cabin Temperature Controller
CTOT	Calculated take-off time
CTR	Controlled Zone

D

Abbreviation	Meaning(s)	Description
DG	Directional Gyro
DH	Decision height	point on G/S where to decide to continue landing or missed approach, similar to MDA, for precision approaches, determined by altimeter, lowest height where an approach can be flown by instrument alone
DLC	Direct lift control	system for steady approaches without changing pitch, as seen on the L-1011-500.
DME	Distance measuring equipment	measures the distance (slant, not on-ground distance) to the tuned in VOR
DTG	Distance to go
DTO	Direct to	GPS function to fly directly to a given point

E

Abbreviation	Meaning(s)	Description
EAT	Estimated Arrival Time
ECEF	Earth-Centred, Earth-Fixed coordinate system	Cartesian 3D coordinate system with origo at the Earth's center of mass and x axis intersecting 0°E, 0°N
EDT	Estimated Departure Time
EFATO	Engine failure after take off	Usually resulting in a force-landing.
EFIS	Electronic Flight Instrument System	Combination of displays (PFD and MFD) with autopilot
EICAS	Engine Indication and Crew Alerting System
EOBT	Estimated off-block time	The estimated time the aircraft will start moving before departure. In essence when the aircraft starts to taxi
ETA	Estimated Time of Arrival
ETOPS	Extended Twin-engine Operational Performance Standards	Standard allowing twin-engined aircraft (eg, the 777 or A330) to fly long distances between potential alternate airports, eg trans-oceanic flights.

F

Abbreviation	Meaning(s)	Description
FAF	Final approach fix
FD	Flight director	horizontal and vertical bars on your PD
FDM	Flight Dynamics Model
FL	Flight Level	Flight level
FLEX	Flex Temp	Performing a take-off (TOGA) at less than full power.
FMA	Flight Mode Annunciator Flight Mode Annunciation	The display of selected autopilot mode(s), typically on the top row of the PFD display in airliners.

G

Abbreviation	Meaning(s)	Description
G/S	Glideslope	provides vertical guidance during ILS, UHF, always goes together with LOC, usually 3deg, usable 10NM from field
GA	Go-Around
GA	General Aviation
GAR	Go-Around
GPS	Global Positioning System	allows a very exact measuring of location all over the world, based on satellites

H

Abbreviation	Meaning(s)	Description
HDG	Heading
HUD	Head up display	Head up display
HSI	Horizontal situation indicator

I

Abbreviation	Meaning(s)	Description
IAF	Initial approach fix
IAP	Instrument approach plate	see Approach Plate, aka. Terminal Procedures
IATA	International Air Transport Association
ICAO	International Civil Aviation Organisation
IFR	Instrument flight rules	0-179: odd thousands, 180-359: even thousands
ILS	Instrument Landing System
IM	Inner marker	See Inner marker

J

Abbreviation	Meaning(s)	Description
JBD	Jet blast deflector

K

Abbreviation	Meaning(s)	Description
KIAS	Knots Indicated Airspeed	IAS in knots

L

Abbreviation	Meaning(s)	Description
LDA	Localizer directional aid	similar to LOC, but offset from runway heading, the approach path is not lined up with runway
LFR	Low Frequency Radio Range	see article LFR
LNAV	Lateral navigation
LOC	Localizer	provides lateral guidance during ILS, VHF, always goes together with G/S, usable 18NM from field
LOC-A		an approach plate that ends with a letter indicates that a circling approach is required
LTA	Lighter than Air

M

Abbreviation	Meaning(s)	Description
MALSR	Medium-intensity ALS with Runway alignment indicator lights	a type of Runway Approach lighting
MAP	Missed approach point	touch down zone of runway
MCDU	Multipurpose Control and Display unit	CDU
MCP	Mode Control Panel	Panel that controls the autopilot
MDA	Minimum descend altitude	during an approach, this specifies the minimum Altitude (MSL) before the runway is in sight and a safe landing can be made
MEA	Mean enroute altitude
MES	Main Engine Start	See APU
METAR	Meteorological Aerodrome Report	METAR
MFD	Multi Function Display unit, sometimes named MDU	Display that can contain all sorts of information, like map, weather and engine status. Often a backup for PFD's
MIRL	Medium-intensity runway lights
MLS	Microwave landing system
MM	Middle marker	Middle marker
MOCA	Minimum obstruction clearance altitude
MSA	Minimum safe altitude	provides minimum of 1000ft clearance from obstructions and terrain
MSFS	Microsoft Flight Simulator	a flight simulator by Microsoft that is now discontinued
MSL	Mean Sea Level	Standardized height figure, Altimeters show the current A/C height over MSL
MTOW	Maximum Takeoff Weight

N

Abbreviation	Meaning(s)	Description
Navaid	Helper for navigation	eg: NDB, Fixes, VOR, GPS
ND	Navigational Display
NDB	Non directional beacon	LW, sends out Morse code of its ID, reception only reliable > 1000ft AGL

O

Abbreviation	Meaning(s)	Description
OAT	Outside air temperature	the temperature of undisturbed air, derived by correcting TAT for compressibility errors
OBS	Omni bearing selector	part of a VOR gauge, used to rotate the course card
OM	Outer marker	Outer marker

P

Abbreviation	Meaning(s)	Description
PAPI	Precision Approach Path Indicator	PAPI, similar to VASI, but more precise, uses four lights
PD	Primary display
PF	Pilot flying	the person that currently controls the airplane, can be either Captain or F/O
PFD	Primary flight display
PFL	Practice forced landing	Practise approach carried out to a suitable field. No landing is made.
PIREP	Pilot Report	(abbreviated UA in the briefing teletype, UUA is urgent PIREP)
PNF	Pilot non-flying	the person who's not the PF
PTS	Practical Test Standards	Guidelines used by the FAA in determining an airmens eligibility to receive their certificate

R

Abbreviation	Meaning(s)	Description
RAIM	Receiver autonomous integrity monitoring
RAT	Ram air temperature	The raw, non-corrected temp. as measured by the temperature probe. Errors due to the Ram effect (air compressed in the probe) and the position (air may be disturbed by parts of the airplane, and also due to the effect of the air compression in front of the plane) RAT may also describe a Ram Air Turbine; a device deployed into the airstream on large aircraft to provided minimum electrical power in the event of generator-failure.
RDF	Radio Direction Finder	see article RDF
RDH	Reference datum height	Height of the glidepath or a nominal vertical path above the runway threshold
RMI	Radio magnetic indicator
RNAV	Area Navigation	flying by longitude/latitude points that are not radio navigation aids, GPS or IRS is usually used.
RTO	Rejected take off
RTOW	Regulated Take Off Weight	See Maximum Takeoff Weight MTOW
RVR	Runway Visual Range	The distance over which a pilot of an aircraft on the centreline of the runway can see the runway surface markings delineating the runway or identifying its centre line

S

Abbreviation	Meaning(s)	Description
SAT	Static air temperature	same as OAT
SDF	Simple directional facility
SFDS	Secondary Flight System Display	Standby EFIS in a single self contained unit, not to be mistaken with MFD
SFD	Secondary Flight Display	Display of the SFDS
SID	Standard instrument departure	for takeoffs, specifies the route from the runway to the first waypoint
STAR	Standard terminal arrival route	for landings, speciefies the route from the last waypoint down to the runway
STOL	Short take off and landing
STOVL	Short take off and vertical landing

T

Abbreviation	Meaning(s)	Description
TACAN	Tactical Air Navigation	Tactical Air Navigation, military
TAF	Terminal aerodrome forecast
TAT	Total air temperature	This is derived by correcting the RAT for position. Still contains an error due to the compressibility of air inside the temperature probe.
TCAS	Traffic Collision Avoidance System
TDZE	Touch down zone elevation	the MSL of the touch down point of a runway
THDG	True Heading
TODR	Take Off Distance Required
TOGA	Take Off / Go Around	Automatic single-switch operation of throttle for Take-off / Go-Around Power.
TOW	Take Off Weight
T&P(s)	Temperatures and pressures	relating to engine systems.

U

Abbreviation	Meaning(s)	Description
UNICOM	Universal Communications	See also: CTAF
UTC	Coordinated Universal Time	Not to be confused with GMT - Greenwich Mean Time

V

Abbreviation	Meaning(s)	Description
V speeds	Velocity speeds	airspeeds important or useful to the operation of aircraft
VASI	Visual approach slope indicator	an approach lighting system, typically two lights left of the runway
VFR	Visual Flight Rules	0-179: odd thousands+500ft, 180-359: even thousands+500ft
VNAV	Vertical navigation
VOR	VHF Omnidirectional Radio Range	VOR, a type of radio navigation system
VORTAC	VOR/TACAN	A co-located VOR and TACAN beacon.
VS	Vertical Speed
VSI	Vertical speed indicator
VTOL	Vertical take off and landing

W

Abbreviation	Meaning(s)	Description
WCA	Wind correction angle
WOW	Weight on wheels	A condition met when the weight of an aircraft are pushing its wheels to the ground, indicating that it is not in the air.

Z

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External links

• Wikipedia (en)
• Wikipedia (de), more detailed and descriptions are english anyway ;-)