Acronyms and Abbreviations in Avionics

Recently, our new FMS team is struggling with avionics technical acronyms and abbreviations. For example, someone was not able to understand “MAP” (tring to think it’s a “geographical map”). However, actually “MAP” stands for “missed approach point”. So here’s a list of acronyms and abbreviations in avionics to help you guys understand “Technical Lazy Word” better, and make an accurate search when facing some new avionics terms.


A

  • A/A: Air to air TACAN function
  • A/C: Aircraft
  • 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
  • ACR: Avionic Communication Router
  • 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 system
  • 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
  • ATR: Air transportable racking
  • ATR: Automatic thrust restoration
  • 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

  • CACTCS: Cabin Air Conditioning and Temperature Control System (pronounced “Cactus”)
  • CAI: Caution advisory panel (sometimes spelled “caution-advisory” or “caution/advisory”)
  • 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
  • CDCCL: Critical Design Configuration Control Limitations
  • CDI: Course deviation indicator
  • CDTI: Cockpit display of traffic information
  • CFIT: Controlled flight into terrain
  • CHP: Course Heading Panel
  • CHT: Cylinder Head Temperature
  • CMU: Communications Management Unit
  • CNS: Communication, navigation and surveillance
  • CNS/ATM: Communication, navigation and surveillance / Air traffic management[1]
  • 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
  • DPU: Display Processor Unit
  • DSP: Digital signal processing
  • DTU: Data transfer unit
  • DUAT: Direct user access terminal
  • DVE: Degraded Visual Environment
  • DRMC : Direct Reading Magnetic Compass

E

  • EADI: Electronic attitude director indicator
  • ECAM: Electronic Centralised Aircraft Monitor
  • ECU: Engine Control Unit (=EEC)
  • EEC: Electronic Engine Control
  • EFD: Electronic flight display
  • EFIS: Electronic flight instrument system
  • EGI: Embedded GPS Inertial
  • EGNOS: European Geostationary Navigation Overlay Service
  • 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
  • EPU: Emergency Power Unit
  • ERAM: En Route Automation Modernization
  • 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
  • FCMC: Fuel Control & Monitoring Computer
  • FCS: Flight Control System
  • FD: Flight Director
  • FDAU: Flight-data acquisition unit
  • 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
  • FQIS: Fuel Quantity Indication System
  • 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: Symbol for unit of pressure, 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: Symbol for unit of frequency, 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)][2]
  • 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

  • KIAS: Knots Indicated airspeed
  • KTAS: Knots true 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 descent 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: Minimum 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
  • MORA: Minimum Off Route Altitude
  • MOSArt: Modular Open System Architecture
  • MPU: Multifunction Processor Unit
  • 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
  • MZFW: Maximum Zero Fuel Weight

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
  • NGS: Nitrogen Generation System, found in aircraft to reduce fire risk in fuel tanks.
  • 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
  • OCH: Obstacle Clearance Height
  • 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
  • SDU: Satellite data unit
  • 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
  • Twr: Tower (Aerodrome Control)
  • TX: Transmit

U

  • UAC: Upper Area Control
  • 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
  • X-Start: Cross-start. Use the air pressure or electrical power from a working engine.

Y

  • YD: Yaw damper
  • Y : YAW

Z

  • ZFW: Zero Fuel Weight