Acronyms and abbreviations in avionics

A

A/A: Air to Air TACAN function

A/P: Autopilot

ABAS: Aircraft-Based Augmentation System

ACARS: Aircraft Communications Addressing and Reporting System

ACAS: Airborne collision avoidance system

ACC: Area Control Centre

ACE: Actuator Control Electronics

ACMS: Aircraft Condition Monitoring System

ACP: Audio Control Panel

ACS: Audio Control System

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 Dependent Surveillance or air data system

ADS-A: Automatic Dependent Surveillance-Address

ADS-B: Automatic dependent surveillance – broadcast

ADS-C: Automatic Dependent Surveillance-Contract

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

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

AGDL: Air-Ground Data Link

AHC: Attitude Heading Control

AHRS: Attitude and Heading Reference Systems

AHRU: Attitude and Heading Reference Unit

AIDS: Aircraft Integrated Data System

AIXM: Aeronautical Information eXchange Model

ALC: Automatic Level Control

ALT: Either; altimeter or altitude

ALT Hold: Altitude Hold Mode

ALTS: Altitude Select

AMLCD: Active-matrix liquid crystal display

AMO: Approved Maintenance Organisation

AMS: Air Management System

ANC: Active Noise Cancellation

ANN: Annunciator – caution warning system normally containing visual and audio alerts to the pilot

ANR: Active Noise Reduction

ANT: Antenna

AOC: Aeronautical Operational Control

AOP: Airport Operating Plan

APARS: Automatic Pressure Altitude Reporting System

APIRS: Attitude and Positioning Inertial Reference System

APOA: Airport of Arrival

APC: Auto Pilot Computer

APOD: Airport of Departure

APM: Aircraft Personality Module

APS: Auto Pilot System

APU: Auxiliary Power Unit

ARINC: Aeronautical Radio, Incorporated

ASD: Aircraft situation display

ASDL: Aeronautical satellite data link

ASR: Airport surveillance radar

ASU: Avionics switching unit

AT: Auto Throttle

ATC: Air traffic control

ATCC: Air Traffic Control Centre

ATCT: Airport Traffic Control Tower

ATCRBS: Air Traffic Control Radar Beacon System

ATCSS: Air traffic control signalling system

ATIS: Automated Terminal Information Service

ATSAW: Airborne Traffic Situational Awareness

ATSU: Air Traffic Services Unit

ATT: Attitude

Avionics: Aviation electronics

AWOS: Automated Weather Observation System

AWACS: Advanced Warning And Control Systems

ALNA: AirLine Network Architecture

B

B RNAV: Basic area navigation

BARO: Barometric indication, setting or pressure

BITE: Built-In Test Equipment

BCRS: Back course

BDI: Bearing distance indicator

BGAN: Broadcast Global Area Network

BER: Beyond Economic Repair

C

CAI: Caution annunciator indicator

CAS: Calibrated airspeed

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

CB: Cumulonimbus cloud

CDA: Continuous descent approach

CDI: Course deviation indicator

CDTI: Cockpit display of traffic information

CFIT: Controlled flight into terrain

CHT: Cylinder Head Temperature

CNS: Communication, navigation, surveillance

CNS/ATM: Communication, navigation, surveillance/air traffic Management

CODEC: Coder/decoder

COMM or COM: Communications transceiver, Communications receiver, or Communications radio transmitter (now, normally: either VHF or UHF; HF communications avionics are usually abbreviated simply HF)

COTS: Commercial off-the-shelf

CPDLC: Controller–pilot data link communications

CPS: Cycles per second

CRT: Cathode ray tube

CTAF: Common traffic advisory frequency

CV/DFDR: Cockpit voice and digital flight data recorder

CVR: Cockpit voice recorder

CWS: Control wheel steering

D

DA: Decision altitude

DA: Drift angle

DAPs: Downlink of aircraft parameters

DCDU: Data link control and display unit

DCL: Departure Clearance via CPDLC

DCP: Display control panel

DFDR: Digital Flight Data Recorder

DFMC: Dual Frequency Multiple Constellation

DG: Directional gyroscope

DGPS: Differential global positioning system

DH: Decision height

DLR: Data link recorder

DME: Distance measuring equipment

DNC: Direct noise canceling

DP: Departure procedures

DSP: Digital signal processing

DTU: Data transfer unit

DUAT: Direct user access terminal

DVE: Degraded Visual Environment

E

EADI: Electronic attitude director indicator

ECU: Engine Control Unit (=EEC)

EEC: Electronic Engine Control

EFD: Electronic flight display

EFIS: Electronic flight instrument system

EGI: Embedded GPS Inertial

EGPWS: Enhanced ground proximity warning system

EGT: Exhaust gas temperature

EHS: Enhanced surveillance

EHSI: Electronic horizontal situation indicator

EICAS: Engine indication crew alerting system

ELT: Emergency locator transmitter

ENC: Electronic noise canceling

ENG: Engine

ENR: Electronic noise reduction

EPR: Engine pressure ratio

ETOP(S): Extended-range twin-engine operation(s)

F

FAA: Federal Aviation Administration

FADEC: Full authority digital engine control

FAF: Final approach fix

FANS: Future Air Navigation System

FAT: Free air temperature

FBO: Fixed Base Operator

FBW: Fly-by-wire

FCC: Flight Control Computer

FCS: Flight Control System

FD: Flight Director

FDPS: Flight plan Data Processing System

FDR: Flight Data Recorder

FDRS: Flight data recorder system

FDU: Flux detector unit

FF: Fuel flow

FG: Flight Guidance

FIC: Flight Information Centre

FIS-B: Flight information services – broadcast

FLIR: Forward-looking infra-red

FLTA: Forward-looking terrain avoidance

FMA: Flight Mode Annunciator

FMGS: Flight Management & Guidance System

FMS: Flight management system

FOB: Fuel On-Board

FREQ: Frequency

FSS: Flight service station

FWS: Flight warning system

FYDS: Flight director/ Yaw damper system

G

GA: Go Around

GAST: GBAS Approach Service Type

GBAS: Ground based augmentation system

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: GBAS Landing System

GLU: GPS landing unit

GMT: Greenwich Mean Time

GND: Ground

GNSS: Global Navigation Satellite System

GO: Go Around

GPS: Global Positioning System

GPWC: Ground proximity warning computer

GPWS: Ground proximity warning system

G/S: Glide Slope

GS: Ground speed

H

"Hg: Inch of Mercury

HDG: Heading

HDG SEL: Heading select

HDOP: Horizontal dilution of precision

HF: High frequency

HHLD: Heading hold

HIRF: High intensity radiated field

HMD: Helmet-mounted display

HPR: High Pressure Rotor

HSD: High-speed data

HSI: Horizontal situation indicator

HSL: Heading select

HUMS: Health and usage monitoring systems

HUD: Head-up display

Hz: Hertz

I

IAP: Instrument approach procedure

IAS: Indicated airspeed

ID: Identify/Identification or identifier

IDENT: Identify/identifier

IDS: Information display system or integrated display system

IFE: In-flight entertainment

IFF: Identification Friend or Foe

IFICS: [(Integrated Flight Instrument and Control System)]

IFR: Instrument Flight Rules

ILS: Instrument landing system

IMC: Instrument meteorological conditions

IND: Indicator

InHg: Inch of Mercury

INS: Inertial Navigation System

IRS: Inertial Reference System

IRU: Inertial reference unit

ISA: International Standard Atmosphere

ISP: Integrated switching panel

ISIS: Integrated standby instrument system

ITT: Interstage turbine temperature

IVSI: Instantaneous vertical speed indicator

J

JTIDS: Joint Tactical Information Distribution System

K

KTAS: Knots true airspeed

KTIS: Knots Indicated airspeed

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

LOPA: Location of Passenger Accommodations

LORAN: Long-range navigation

LPR: Low Pressure Rotor

LPV: Localizer performance with vertical guidance

LRU: Line-replaceable unit

LTE: Loss of Tail Rotor Effectiveness Helicopters

LVP: Low visibility procedures, a designated state of operations at aerodromes where instrument approaches and low visibility takeoff procedures are using during inclement weather

LX: Lightning

M

MAP: Manifold absolute pressure or missed approach point

MAPS: Minimum Aviation Performance Standards

MB: Marker beacon

MCBF: Mean cycles between failures

MCDU: Multi-purpose/Multi-function Control and Display Unit

MDA: Minimum decent altitude

MEA: Minimum en-route altitude

MEL: Minimum equipment list

METAR: Meteorological Aerodrome Report

MCP: Mode control panel

MF: Medium frequency

MFD: Multi-function display

MFDS: Multi-function display system

MIC: Microphone

MIDS: Multifunctional information distribution system

MILSPEC: Military specification

MKP: Multi-function Keypad

MKR: Marker beacon

MLS: Microwave landing system

MM: Middle marker

MMD: Moving map display

MNPS: [Minimmum navigation performance specifications]

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

MOPS: Minimum Operational Performance Standard

MOSArt: Modular Open System Architecture

MSA: Minimum safe altitude

MSG: Message

MSP: Modes S-Specific Protocol

MSSS: Mode S-Specific Services

MTBF: Mean time between failures

MTBUR: Mean time between unscheduled removals

MTTF: Mean time to failure

MVA: Minimum vectoring altitude

MVFR: Marginal visual flight rules

N

N1: Low Pressure rotor (spool) speed (see Jet engine)

N2: High Pressure rotor (spool) speed (see Jet engine)

NAS: National Airspace System

NAV: Navigation receiver (normally VHF navigation receiver for VOR system.)

Navaid: Navigational aid

NAVCOMM, NAV/COM or NAV-COM: Combination navigation and communications equipment (normally VHF navigation receiver integrated with VHF communications transceiver).

NAVSTAR-GPS: NAVigation Satellite Timing And Ranging (The formal name for the space-borne or satellite navigation system)

NCAT: National Center for Aviation Training

NCATT: National Center for Aircraft Technician Training

ND: Navigation display

NDB: Non-directional radio beacon

NFF: No fault found

NM or NMI: Nautical mile

NORDO: No radio

NoTAM: Notice to Airmen

NPA: Non-precision approach

NVD: Night vision device

NVG: Night vision goggles

O

OAT: Outside air temperature

OBS: Omnibearing selector

OCC: Operations control center

OM: Outer marker

OWE/OEW: Operating Weight Empty/Operating empty weight

P

PA: Public address system

PAEW: Personnel and equipment working

PAL: Pilot Activated Lighting

PAPI: Precision approach path indicator

PAR: Precision approach radar

PCL: Pilot Controlled Lighting

P-Code: GPS precision code

PD: Profile descent

PDC: Pre-Departure Clearance

PDOP: Position dilution of precision

PESA: Passive electronically scanned array

PFD: Primary flight display or primary flight director

PMG: Permanent magnet generator

PND: Primary navigation display

PNR: Passive noise reduction

POF: Phase of flight

POH: Pilot's Operating Handbook

POS: Position

P-RNAV: precision area navigation

PRA: Pre-recorded announcement

PSR: Primary surveillance radar

PSU: Passenger service unit

PTT: Push-to-talk

Q

QAR: Quick Access Recorder

QNH: Barometric pressure adjusted to sea level

QRH: Quick Reference Handbook

R

RA: Resolution advisory (TCAS)

Rad Alt: Radio Altitude

Radar: RAdio Detection And Ranging

RAI: Radio altimeter indicator

RAIM: Receiver-autonomous integrity monitoring, also remote autonomous integrity monitoring

RALT: Radar or radio altimeter

RAT: Ram air turbine

RCR: Reverse current relay

RCVR: Receiver

RDMI: Radio distance magnetic indicator

RDP: Radar data processing system

RDR: Radar

REF: Reference

REIL: Runway end identifier lights

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

RPA: Remotely piloted aircraft (Unmanned aerial vehicle)

RPM: Revolutions per minute

RSP: Reversion switch panel

RTE: Route

RVR: Runway visual range

RVSM: Reduced vertical separation minimum

RX: Receiver

S

SAR: Search and Rescue, Smart ACMS Recorder

SAT: Static air temperature

SATCOM: Satellite communication

SATNAV: Satellite navigation

SD: Secure digital

SDF: Simplified directional facility

SELCAL: Selective calling

SID: Standard instrument departure

SIU: Satellite interface unit

SMS: Short Messaging Service

SNR: Signal-to-noise ratio

SPKR: Speaker

SQ or SQL: Squelch

SRS: Speed Reference System

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

STCA: Short-Term Conflict Alert

STP: Standard temperature and pressure

SUA: Special use airspace

T

TA: Traffic advisory (see 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 and warning system

TBO: Time before overhaul, or time between overhaul

TCA: Throttle control assembly, or terminal control area

TCAS: Traffic collision 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 en route procedures

TFR: Temporary flight restrictions

TFT: Thin-film transistor

TGT: Turbine gas temperature, or target

THDG: True heading

TIS: Traffic information service

TIT: Turbine Inlet Temperature

TK: Track angle

TKE: Track-angle error

TLA: Thrust Lever Angle

TLA: Three-letter acronym

TOC: Top of climb

TOD: Top of Descent point

TOGA or TO/GA: Takeoff/Go-around switch, Takeoff/go-around thrust

TOT: Turbine outlet temperature

TR or T/R: Transmitter receiver or transceiver

T/R: Thrust Reverser or Tail Rotor

TRACON: Terminal radar approach control

TRANS: Transmit, Transmission, or Transition

TRK: Track

TRP: Mode S transponder

TTL: Tuned to Localizer

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

UAV: Unmanned aerial vehicle

UHF: Ultra-high frequency

ULB: Underwater locator beacon

USB: Universal Serial Bus

UTC: Universal Time Coordinate

V

V: Volts or voltage

V/L: VOR/Localizer

V/NAV: Vertical navigation

V/R: Voltage regulator

V/REF: Reference velocity

V/S: Vertical speed

V/TRK: Vertical track

VASI: Visual approach slope indicator

VASIS: Visual approach slope indicator (system)

VDF: VHF Direction Finding

VDL: VHF Data Link

VDR: VHF digital radio

VFO: Variable frequency oscillator

VFR: Visual flight rules

VG/DG: Vertical gyroscope/directional gyroscope

VGA: Video Graphics Array

VHF: Very high frequency

VMC: Visual meteorological conditions or minimum control speed with critical engine out

VNE: Never exceed speed

VNO: Maximum structural cruising speed

VNR: VHF navigation receiver

VOR: VHF omnidirectional range and ranging

VOR/DME: VOR with Distance measuring equipment

VOR/MB: VOR marker beacon

VORTAC: VOR and TACAN combination

VOX: Voice transmission

VPA: Vertical Path Approach

VPATH: Vertical path

VRP: Visual Point of Reference

VSI: Vertical speed indicator

VSM: Vertical separation limit

VSO: Stall speed in landing configuration

VSWR: Voltage–standing wave ratio

VX: Speed for best angle of climb

VY: Speed for best rate of climb

W

WAAS: Wide Area Augmentation System

WD: Wind direction

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

WS: Wind shear

WX: Weather

WXR: Weather radar system

WYPT: Waypoint

X

XCVR: Transceiver

XFR: Transfer

XMIT: Transmit

XMSN: Transmission

XMTR: Transmitter

XPDR: Transponder

XTK: Crosstrack

Y

YD: Yaw damper

Y : YAW