Common Avionics Acronyms
A
: Amps.
ACARS: Aircraft Communications Addressing and Reporting System.
ACAS: Airborne Collision Avoidance System.
ACP: Audio Control Panel.
ACS: Audio Control System.
A/D: Analog to Digital.
ADAHRS: Air Data and Attitude Heading Reference System.
ADC: Air Data Computer.
ADF: Automatic Direction Finder.
ADI: Attitude Director Indicator.
ADIRS: Air Data Inertial Reference System.
ADIRU: Air Data Inertial Reference Unit.
ADM: Air Data Module.
ADS: Either; Automatic Dependant Surveillance or Air Data System.
ADS-A: Automatic Dependant Surveillance /Address.
ADS-B: Automatic Dependant Surveillance/Broadcast.
ADSEL: Address Selective.
ADSP: Automatic Dependant Surveillance Panel.
AET: Aircraft Electronics Technician (A NCATT certified technician).
AFCS: Automatic Flight Control System.
AFD: Autopilot Flight Director.
AFDC: Autopilot Flight Director Computer.
AFDS: Autopilot Flight Director System.
AFIS: Either; Automatic Flight Information Service or Airborne Flight Information System.
AGACS: Automatic Ground-Air Communications System, is also known as ATCSS or data link.
AGC: Automatic Gain Control.
AHC: Attitude Heading Control.
AHRS: Attitude Heading Reference System.
Air Data: Various parameters that can be derived from knowledge of the air mass surrounding the aircraft.
ALC: Automatic Level Control.
ALT: Either; Altimeter or Altitude.
ALT Hold: Altitude Hold Mode.
ALTS: Altitude Select.
AMLCD: Active Matrix Liquid Crystal Display.
ANC: Active Noise Cancellation.
ANN: Annunciator- caution warning system normally containing visual and audio alerts to the pilot.
ANR: Active Noise Reduction.
ANT: Antenna.
A/P: Autopilot.
APC: Autopilot Computer.
APS: Autopilot System.
ASD: Aircraft Situation Display.
ASDL: Aeronautical Satellite Data Link.
ASR: Airport Surveillance Radar.
ASU: Avionics Switching Unit.
ATCRBS: Air Traffic Control Radar Beacon System.
ATCSS: Air Traffic Control Signaling System.
ATI: Unit of measure for instrument size, a standard 3ยจรป cutout is a 3ATI.
ATT: Attitude.
Avionics: Aviation electronics.
AWG: American Wire Gauge.
B
B RNAV: Basic Area Navigation.
BARO: Barometric indication, setting or pressure.
BCRS: Back Course.
BDI: Bearing Distance Indicator.
BGAN: Broadcast Global Area Network.
C
CAI: Caution Annunciator Indicator.
CAT I: Operational performance Category 1.
CAT I Enhanced. Allows for lower minimums than CAT I in some cases to CAT 2 minimums.
CAT II: Operational performance Category II.
CAT IIIa: Operational performance Category IIIa.
CAT IIIb: Operational performance Category IIIb.
CAT IIIc: Operational performance Category IIIc.
CODEC: Coder/Decoder.
CDI: Course Deviation Indicator.
CFIT: Controlled Flight Into Terrain.
COMM or COM: Communications Receiver.
CNS: Communication, Navigation, Surveillance.
CNS/ATM: Communication, Navigation, Surveillance/Air Traffic Management.
CPDLC: Controller-Pilot Data Link Communication.
CPS: Cycles Per Second.
CRT: Cathode Ray Tube.
CTAF: Common Traffic Advisory Frequency.
CV/DFDR: Cockpit Voice and Digital Flight Recorder.
CVR: Cockpit Voice Recorder.
CWS: Control Wheel Steering.
D
DA: Drift Angle.
DG: Directional Gyroscope.
DGPS: Differential Global Positioning System.
DH: Decision Height.
DME: Distance Measuring Equipment.
DNC: Direct Noise Canceling.
DP: Departure Procedures.
DSP: Digital Signal Processing.
DUAT: Direct User Access Terminal.
E
EADI: Electronic Attitude Director Indicator.
EFD: Electronic Flight Display.
EFIS: Electronic Flight Instrument System.
EGPWS: Enhanced Ground Proximity Warning System.
EGT: Exhaust Gas Temperature.
EHSI: Electronic Horizontal Situation Indicator.
EICAS: Engine Indication Crew Alerting System.
ELT: Emergency Locator Transmitter.
ENC: Electronic Noise Canceling.
ENR: Electronic Noise Reduction.
EPR: Engine Pressure Ratio.
F
FADEC: Full Authority Digital Engine Control.
FAT: Free Air Temperature.
FDRS: Flight Data Recorder System.
FDU: Flux Detector Unit.
FF: Fuel Flow.
FIS-B: Flight Information Services- Broadcast.
FLIR: Forward Looking Infra-Red.
FLTA: Forward Looking Terrain Avoidance.
FMS: Flight Management System.
FREQ: Frequency.
FYDS: Flight director/ Yaw Damper System.
G
GCAS: Ground Collision Avoidance System.
GCU: Generator Control Unit.
GDOP: Geometric Dilution Of Precision.
GGS: Global positioning system Ground Station.
GHz: Gigahertz.
GLNS: GPS Landing and Navigation System.
GLNU: GPS Landing and Navigation Unit.
GLONASS: Global Navigation Satellite System.
GLS: GPS Landing System.
GLU: GPS Landing Unit.
GND: Ground.
GNSS: Global Navigation Satellite System.
GMT: Greenwich Mean Time.
GPS: Global Positioning Satellite or Global Positioning System.
GPWC: Ground Proximity Warning Computer.
GPWS: Ground Proximity Warning System.
H
HDG: Heading.
HDG SEL: Heading Select.
HDOP: Horizontal Dilution Of Precision.
HF: High Frequency.
HHLD: Heading Hold.
HSD: High Speed Data.
HSI: Horizontal Situation Indicator.
HSL: Heading Select.
HUD: Head-Up Display.
Hz: Hertz.
I
IAS: Indicated Airspeed.
ID: Identify/Identification or identifier.
IDENT: Identify/Identifier.
IDS: Information Display System or Integrated Display System.
IFE: In-Flight Entertainment.
IFR: Instrument Flight Regulations.
ILS: Instrument Landing System.
IMC: Instrument Meteorological Conditions.
InHg: Inches of Mercury.
IND: Indicator.
ISA: International Standard Atmosphere.
ISP: Integrated Switching Panel.
ITT: Interstage Turbine Temperature.
IVSI: Instantaneous Vertical Speed Indicator.
J
K
kHz: Kilohertz.
L
LAAS: Local Area Augmentation System.
LADGPS: Local Area Differential GPS.
LCD: Liquid Crystal Display.
LDGPS: Local area Differential Global Positioning Satellite.
LED: Light Emitting Diode.
LMM: Locator Middle Marker.
LOC: Localizer.
LOM: Locator Outer Marker.
LRU: Line Replaceable Unit
M
MAP: Manifold Absolute Pressure or Missed Approach Point.
MB: Marker Beacon.
MCBF: Mean Cycles Between Failures.
MDA: Minimum Decent Altitude.
MEL: Minimum Equipment List.
MF: Medium Frequency.
MFD: Multi-Function Display.
MFDS: Multi-Function Display System.
MHz: Megahertz.
MIC: Microphone.
MILSPEC: Military Specification.
MKR: Marker Beacon or Marker.
MLS: Microwave Landing System.
MMD: Moving Map Display.
MOA: Military Operations Area.
Mode A: Transponder pulse code reporting.
Mode C: Transponder code and altitude reporting.
Mode S: Transponder code, altitude, and TCAS reporting.
MSG: Message.
MSP: Modes S Specific Protocol.
MSSS: Mode S Specific Services.
MTBF: Mean Time Between Failures.
MTTF: Mean Time To Failure.
N
NAS: National Airspace System.
NAV: Navigation receiver.
Navaid: Navigational Aid.
NAVCOMM: Navigation and Communications equipment or receiver.
NAVSTAR-GPS: The formal name for the space-borne or satellite navigation system.
NCATT: National Center for Aircraft Technician Training.
ND: Navigation Display.
NDB: Non-Directional radio Beacon.
NFF: No Fault Found.
NM or NMI: Nautical Mile.
NPA: Non-Precision Approach.
O
OAT: Outside Air Temperature.
OBS: OmniBearing Selector.
OM: Outer Marker.
P
P-Code: GPS precision code.
PAPI: Precision Approach Path Indicators.
PAR: Precision Approach Radar.
PD: Profile Descent.
PDOP: Position Dilution Of Precision.
PFD: Primary Flight Display or Primary Flight Director.
PMG: Permanent Magnet Generator:
PND: Primary Navigation Display.
PNR: Passive Noise Reduction.
POS: Position.
PSR: Primary Surveillance Radar.
PTT: Push To Talk.
Q
R
RAI: Radio Altimeter Indicator.
RAIM: Receiver Autonomous Integrity Monitoring.
RALT: Radar or Radio Altimeter.
RCR: Reverse Current Relay.
RCVR: Receiver.
RDMI: Radio Distance Magnetic Indicator.
RDP: Radar Data Processing system.
RDR: Radar.
REF: Reference.
REL: Relative.
RF: Radio Frequency.
RFI: Radio Frequency Interference.
RHSM: Reduced Horizontal Separation Minimal.
RLG: Ring Laser Gyroscope.
RLY: Relay.
RMI: Radio Magnetic Indicator.
R-NAV: Area Navigation.
RNG: Range.
RNP: Required Navigation Performance.
ROC: Rate Of Climb.
ROD: Rate Of Descent.
RPM: Revolutions Per Minute.
RTE: Route.
RVR: Runway Visual Range.
RVSM: Reduced Vertical Separation Minimum.
RX: Receiver.
S
SAT: Static Air Temperature.
SATCOM: Satellite Communication.
SATNAV: Satellite Navigation.
SD: Secure Digital.
SID: Standard Instrument Departure.
SIU: Satellite Interface Unit.
SL: Sensitivity Level.
SMS: Short Messaging Service.
SNR: Signal to Noise Ratio.
SPKR: Speaker.
SQ or SQL: Squelch.
SSCV/DR: Solid State Cockpit Voice/Data Recorder.
SSCVR: Solid State Cockpit Voice Recorder.
SSFDR: Solid State Flight Data Recorder.
SSR: Secondary Surveillance Radar.
STAR: Standard Terminal Arrival Route.
STARS: Standard Terminal Automation Replacement System.
STC: Supplemental Type Certificate.
STP: Standard Temperature and Pressure.
SUA: Special Use Airspace.
T
TA: Traffic Advisory (TCAS).
TACAN: Tactical Air Navigation system.
Tach: Tachometer.
TAD: Terrain Awareness Display.
TAF: Terminal Area Forecast.
TAS: True Airspeed.
TAT: True Air Temperature or Total Air Temperature.
TAWS: Terrain Awareness Warning System.
TBO: Time Before Overhaul or Time Between Overhaul.
TCA: Throttle Control Assembly or Terminal Control Area.
TCAS: Traffic Collision Alert and avoidance System.
TCF: Terrain Clearance Floor.
TCN: TACAN
TCU: TACAN Control Unit.
TDOP: Time Dilution Of Precision.
TDR: Transponder (in some cases).
TERPS: Terminal Instrument Procedures or Terminal EnRoute Procedures.
TFR: Temporary Flight Restrictions.
TFT: Thin Film Transistor.
TGT: Turbine Gas Temperature or Target.
THDG: True Heading.
TIAS: True Indicated Airspeed.
TIS: Traffic Information Service.
TK: Track Angle.
TKE: Track Angle Error.
TOT: Turbine Outlet Temperature.
TR or T/R: Transmitter Receiver or transceiver.
TRACON: Terminal Radar Approach Control.
TRANS: Transmit, Transmission, or Transition.
TRK: Track.
TRP: Mode S Transponder.
TTR: TCAS II Transmitter/Receiver.
TTS: Time to Station.
TVE: Total Vertical Error.
TWDL: Two-Way Data Link, or Terminal Weather Data Link.
TWDR: Terminal Doppler Weather Radar.
TWIP: Terminal Weather Information for Pilots.
TWR: Terminal Weather Radar.
TX: Transmit.
U
UART: Universal Asynchronous Receiver Transmitter.
UHF: Ultra-High Frequency.
ULB: Underwater Locator Beacon.
USB: Universal Serial Bus.
UTC: Universal Time Coordinate.
V
V: Volts or voltage.
VASI: Visual Approach Slope Indicator.
VDL: VHF Data Link.
VDR: VHF Digital Radio.
VFO: Variable Frequency Oscillator.
VFR: Visual Flight Regulations.
VG/DG: Vertical Gyroscope/Directional Gyroscope.
VGA: Video Graphics Array.
VHF: Very High Frequency.
V/L: VOR/Localizer.
VMC: Visual Meteorological Conditions or minimum control speed with critical engine out.
V/NAV: Vertical Navigation.
VNE: never exceed speed.
VNO: maximum structural cruising speed.
VNR: VHF Navigation Receiver.
VOR: VHF Omnidirectional Radio and Ranging.
VOR/DME: VOR with Distance Measuring Equipment.
VOR/MB: VOR Marker Beacon.
VORTAC: VOR and TACAN combination.
VOX: Voice Transmission.
VPATH: Vertical Path.
V/R: Voltage Regulator.
V/REF: Reference Velocity.
V/S: Vertical Speed.
VSI: Vertical Speed Indicator.
VSM: Vertical Separation Limit.
VSO: stall speed in landing configuration.
VSWR: Voltage Standing Wave Ratio.
V/TRK: Vertical Track.
VX: speed for best angle of climb.
VY: speed for best rate of climb.
W
WAAS: Wide Area Augmentation System.
WD/WINDR: Wind Direction.
WMA: WXR Waveguide Adapter.
WMI: WXR Indicator Mount.
WMS: Wide area Master Station.
WMSC: Weather Message Switching Center.
WMSCR: Weather Message Switching Center Replacement.
WPT: Waypoint.
WRT: WXR Receiver Transmitter.
WX: Weather.
WXR: Weather Radar System.
WYPT: Waypoint.
X
XCVR: Transceiver.
XFR: Transfer.
XMIT: Transmit.
XMSN: Transmission.
XMTR: Transmitter.
XPDR: Transponder.
XTK: crosstrack.
Y&Z
YD: Yaw Damper.