Glossary
Learn the meaning and definitions of 380 acronyms and abbrevations used in ATPL exams and the Exam Copilot question bank.
- %MAC
- Percentage Mean Aerodynamic Chord
- AAIM
- Air Autonomous Integrity Monitoring
- AAL
- Above Aerodrome Level
- ABAS
- Air Based Augmentation System
- ABS
- Automatic Braking System
- ABV
- Above...
- AC
- Met: Altocumulus
- Electrics: Alternating Current
- ACAS
- Airborne Collision Avoidance System
- ACMS
- Aeroplane Condition Monitoring System
- ACN
- Aircraft Classification Number
- AD
- Aerodrome
- ADC
- Air Data Computer
- ADF
- Automatic Direction Finder
- ADI
- Attitude and Direction Indicator
- ADS-B
- Automatic Dependent Surveillance - Broadcast
- AHRS
- Attitude and Heading Reference System
- AFCS
- Automatic Flight Control System
- AFIS
- Aerodrome Flight Information Service
- AFM
- Aircraft Flight Manual
- AGL
- Above Ground Level
- AI
- Attitude Indicator
- AIP
- Aeronautical Information Publication
- AIP ENR
- Aeronautical Information Publication Enroute
- AIP GEN
- Aeronautical Information Publication General
- AIRAC
- Aeronautical Information Regulation and Control
- AIREP
- Air Report
- AIRMET
- Information in plain language concerning weather significant to light aircraft operations at or below 10,000FT
- AIS
- Aeronautical Information Service
- AM
- Amplitude Modulated
- AMSL
- Above Mean Sea Level
- ALU
- Arithmetic and Logic Unit
- ANO
- Air Navigation Order
- ANS
- Autonomic Nervous System
- AOC
- Air Operator Certificate
- AP
- Autopilot
- APCH
- Approach
- APP
- Approach Control
- APU
- Auxiliary Power Unit
- APV
- Approach with Vertical Guidance
- ARP
- Aerodrome Reference Point
- AS
- Altostratus
- ASDA
- Accelerate Stop Distance Available
- ASDR
- Accelerate Stop Distance Required
- ASI
- Air Speed Indicator
- ASR
- Area Surveillance Radar
- ATA
- Actual Time of Arrival
- ATC
- Air Traffic Control
- ATD
- Actual Time of Departure
- ATIS
- Automatic Terminal Information Service
- ATM
- Air Traffic Management
- ATPL
- Airline Transport Pilot Licence
- AUM
- All Up Mass
- AVGAS
- Aviation Gasoline
- BEM
- Basic Empty Mass
- BFO
- Beat Frequency Oscillator
- BKN
- METAR/TAF code for 5-7 oktas of cloud
- BOD
- Bottom Of Descent
- BMI
- Body Mass Index
- c
- The speed of light, 30,000,000 metres per second
- CA
- Coarse Acquisition
- CAS
- Calibrated Air Speed
- CAP
- Civil Aviation Publication
- CAT
- Clear Air Turbulence
- CAVOK
- Ceiling and Visibility OK
- CB
- Cumulonimbus
- CC
- Cirrocumulus
- CDI
- Course Deviation Indicator
- CDU
- Control and Display Unit
- CG
- Centre of Gravity
- CHT
- Cylinder Head Temperature
- CI
- Cirrus
- CLTOM
- Climb Limited Take Off Mass
- CNS
- Central Nervous System
- COAT
- Corrected Outside Air Temperature
- CO
- Carbon Monoxide
- CO2
- Carbon Dioxide
- CPL
- Commercial Pilot's Licence
- CPU
- Central Processing Unit
- CRM
- Crew Resource Management
- CS
- Met: Cirrostratus
- Air Law: Contracting State
- CS25
- Certification Specification 25
- CSD
- Constant Speed Drive
- CSDU
- Constant Speed Drive Unit
- CTA
- Control Area
- CTR
- Control Zone
- CU
- Cumulus
- CVR
- Cockpit Voice Recorder
- CVOR
- Conventional VHF Omnidirectional Range
- CWS
- Control Wheel Steering
- D-ATIS
- Data Link Automatic Terminal Information Service
- D-VOLMET
- Data Link VOLMET
- DA
- Altimetry: Density Altitude
- Approaches: Decision Altitude
- DADC
- Digital Air Data Computer
- DALR
- Dry Adiabatic Lapse Rate
- DAP
- Downlink Aircraft Parameters
- DC
- Direct Current
- DCDU
- Data Communication Display Unit
- DF
- Direction Finder
- DGI
- Directional Gyro Instrument
- DH
- Decision Height
- DME
- Distance Measuring Equipment
- DOC
- Designated Operational Coverage
- DOM
- Dry Operating Mass
- DP
- Dew Point
- DR
- Dead Reckoning
- DVOR
- Doppler VHF Omnidirectional Range
- EASA
- European Aviation Safety Agency
- EAS
- Equivalent Air Speed
- EAT
- Expected Approach Time
- EFIS
- Electronic Flight Information System
- EICAS
- Engine Indicating and Crew Alerting System
- ECAM
- Electronic Centralised Aircraft Monitor
- EGNOS
- European Geostationary Navigation Overlay System
- EGT
- Exhaust Gas Temperature
- EGPWS
- Enhanced Ground Proximity Warning System
- EHF
- Extremely High Frequency
- EHS
- Enhanced Surveillance
- ELS
- Elementary Surveillance
- EMBD
- Embedded
- ENR
- En Route
- EPC
- Echo Protection Circuit
- EPR
- Engine Power Ratio
- ERA
- En Route Alternate (Aerodrome)
- ETD
- Estimated Time of Departure
- ETOPS
- Extended Range Twin Engine Operational Performance Standards
- f
- Frequency
- FADEC
- Full Authority Digital Engine Control
- FAF
- Final Approach Fix
- FANS
- Future Air Navigation System
- FBW
- Fly By Wire
- FCL
- Flight Crew Licence
- FCOC
- Fuel Cooled Oil Cooler
- FCU
- Fuel Control Unit
- FD
- Flight Director
- FDE
- Fault Detection and Exclusion
- FDR
- Flight Data Recorder
- FEP
- Flight Envelope Protection
- FEW
- METAR/TAF code for 1-2 oktas of cloud
- FIR
- Flight Information Region
- FIS
- Flight Information Service
- FL
- Flight Level
- FLTA
- Forward Looking Terrain Avoidance
- FLLTOM
- Field Length Limited Take Off Mass
- FM
- Frequency Modulated
- FMA
- Flight Mode Annunciator
- FMC
- Flight Management Computer
- FMS
- Flight Management System
- FOD
- Foreign Object Damage
- FPM
- Feet per Minute
- FTE
- Flight Technical Error
- FWS
- Flight Warning System
- GAMET
- Area forecast for low-level flights
- GBAS
- Ground Based Augmentation System
- GDOP
- Geometric Dilution of Precision
- GEN
- General
- GES
- Ground Earth Station
- GLONASS
- Global Orbiting Navigation Satellite System (Russia)
- GNSS
- Global Navigation Satellite System
- GP
- Glide Path
- GPS
- Global Positioning System (USA)
- GPWS
- Ground Proximity Warning System
- GS
- Groundspeed
- HDG
- Heading
- HDOP
- Horizontal Dilution of Precision
- HF
- Radio Waves: High Frequency
- Human Performance: Human Factors
- HMI
- Human Machine Interface
- HMR
- Humidity Mixing Ratio
- HP
- High Pressure
- hPa
- Hectopascal
- HSI
- Horizontal Situation Indicator
- IAS
- Indicated Air Speed
- IATA
- International Air Transport Association
- ICAO
- International Civil Aviation Organisation
- IF
- Intermediate Approach Fix
- IFR
- Instrument flight rules
- ILS
- Instrument Landing System
- IM
- Inner Marker
- IMC
- Instrument meteorological conditions
- INS
- Inertial Navigation System
- IOAT
- Indicated Outside Air Temperature
- IRS
- Inertial Reference System
- ISA
- International Standard Atmosphere
- ITCZ
- Inter Tropical Convergence Zone
- ITU
- International Telecommunications Union
- LCTR
- Locators
- LEMAC
- Leading Edge of Mean Aerodynamic Chord
- LF
- Low Frequency
- LLZ
- Localiser
- LM
- Landing Mass
- LP
- Low Pressure
- LPV
- Localiser Performance with Vertical guidance
- LRNS
- Long Range Navigation System
- LSS
- Local Speed of Sound
- LVO
- Low Visibility Operations
- MAC
- Mean Aerodynamic Chord
- MAG
- Magnetic
- MAP
- Manifold Absolute Pressure
- MAUM
- Maximum All Up Mass
- MCDU
- Multi Control Display Unit
- MCP
- Mode Control Panel
- MDA
- Minimum Descent Altitude
- MEL
- Minimum Equipment List
- MET
- Meteorology
- METAR
- Meteorological Actual Report
- MF
- Medium Frequency
- MLM
- Maximum Landing Mass
- MLS
- Microwave Landing System
- MLSM
- Maximum Structual Landing Mass
- MM
- Middle Marker
- MMEL
- Master Minimum Equipment List
- MNPS
- Minimum Navigation Performance Specification
- MOPSC
- Maximum Operational Passenger Seating Configuration
- MRJT
- Medium Range Jet Transport
- MSL
- Mean Sea Level
- MSTOM
- Maximum Structual Take Off Mass
- MTOM
- Maximum Take Off Mass
- MTR
- Maximum Theoretical Range
- MTW
- Mountain Waves
- MWO
- Meteorological Watch Office
- MZFM
- Maximum Zero Fuel Mass
- NAR
- North American Routes
- navaid
- Navigation Aid
- ND
- Navigation Display
- NDB
- Non-Directional Beacon
- NIHL
- Noise Induced Hearing Loss
- NOSIG
- METAR/TAF code for No Significant Change
- NOTAM
- Notice To Airmen
- NS
- Nimbostratus
- NSC
- METAR/TAF code for No Significant Cloud
- NSE
- Navigation System Error
- NTOFP
- Net Take Off Flight Path
- OAT
- Outside Air Temperature
- OBI
- Omni Bearing Indicator
- OBS
- Omni Bearing Selector
- OEI
- One Engine Inoperative
- OIS
- Obstacle Identification Surface
- OM
- Outer Marker
- OPC
- Operator Proficiency Check
- OVC
- METAR/TAF code for 8 oktas of cloud
- PA
- Approaches: Precision Approach
- Altimetry: Pressure Altitude
- PANS
- Procedures for Air Navigation Services
- PAPI
- Precision Approach Path Indicators
- PAR
- Precision Approach Radar
- PBN
- Performance Based Navigation
- PCN
- Pavement Classification Number
- PDE
- Path Definition Error
- PFD
- Primary Flight Display
- PDOP
- Position Dilution of Precision
- PF
- Pilot Flying
- PIC
- Pilot In Command
- PIREP
- Pilot Report
- PLLM
- Performance Limited Landing Mass
- PLTOM
- Performance Limited Take Off Mass
- PNF
- Pilot Non Flying
- PNS
- Peripheral Nervous System
- PPL
- Private Pilot Licence
- PRF
- Pulse Repetition Frequency
- PRP
- Pulse Repetition Period
- PSC
- Polar Stereographic Chart
- PSI
- Pounds per Square Inch
- PSR
- Primary Surveillance Radar
- PTU
- Power Transfer Unit
- QDM
- Magnetic bearing from an aircraft to a beacon or station
- QDR
- Magnetic bearing from a beacon or station to an aircraft
- QFE
- Static pressure measured at an aerodrome
- QFF
- Static pressure at MSL calculated from QFE using actual temperature lapse rates
- QNH
- Static pressure at MSL calculated from QFE using ISA temperature lapse rates
- QTE
- True bearing from a beacon or station to an aircraft
- QUJ
- True bearing from an aircraft to a beacon or station
- RA
- Resolution Advisory
- RAIM
- Receiver Autonomous Integrity Monitoring
- RAS
- Rectified Air Speed
- RAT
- Ram Air Temperature
- RBI
- Relative Bearing Indicator
- RCC
- Rescue Co-Ordination Centre
- REM
- Rapid Eye Movement
- RH
- Relative Humidity
- RLM
- Regulated Landing Mass
- RMI
- Radio Magnetic Indicator
- RNAV
- Radio Navigation
- ROC
- Rate Of Climb
- ROD
- Rate Of Descent
- RPM
- Revolutions Per Minute
- RTO
- Rejected Take Off
- RTOM
- Regulated Take Off Mass
- RVR
- Runway Visual Range
- RVSM
- Reduced Vertical Separation Minimum
- RWY
- Runway
- SALR
- Saturated Adiabatic Lapse Rate
- SAR
- Search And Rescue
- SARP
- Standards And Recommended Practices
- SAT
- Static Air Temperature
- SBAS
- Space Based Augmentation System
- SC
- Stratocumulus
- SCT
- METAR/TAF code for 3-4 oktas of cloud
- SELCAL
- Selective Calling System
- SFC
- Altimetry and Charts: Surface
- Performance and Engines: Specific Fuel Consumption
- SHF
- Super High Frequency
- SID
- Standard Instrument Departure
- SIGMET
- Information concerning en route weather phenomena which may affect the safety of aircraft operations
- SKC
- METAR/TAF code for sky clear
- SLS
- Side Lobe Suppression
- SMR
- Humidity: Saturation Mixing Ratio
- Radar: Surface Movement Radar
- SOP
- Standard Operating Procedure
- SpMR
- Specific Mixing Ratio
- SPS
- Pressure: Standard Pressure Setting (1013.25hPa)
- GNSS: Space Segment
- SR
- Specific Range
- SSB
- Single Sideband
- SSR
- Secondary Surveillance Radar
- ST
- Stratus
- STAR
- Standard Arrival Route
- STD
- Simulator Training Device
- SVP
- Saturation Vapour Pressure
- TACAN
- Tactical Air to Navigation (Navaid)
- TA
- Traffic Advisory
- TAF
- Terminal Aerodrome Forecast
- TAS
- True Air Speed
- TAT
- Total Air Temperature
- TCAC
- Tropical Cyclone Advisory Centre
- TDC
- Top Dead Centre
- TDOP
- Time Dilution of Precision
- TEM
- Threat and Error Management
- TEMAC
- Trailing Edge of Mean Aerodynamic Chord
- TGT
- Turbine Gas Temperature
- TL
- Traffic Load
- TLA
- Throttle Lever Angle
- TMA
- Terminal Control Area
- TOD
- Take Off Distance
- TODA
- Take Off Distance Available
- TODR
- Take Off Distance Required
- TOM
- Take Off Mass
- TORA
- Take Off Runway Available
- TRS
- Tropical Revolving Storm
- TRU
- Transformer Rectifier Unit
- TS
- Thunderstorm
- TUC
- Time of Useful Conciousness
- U/S
- Unserviceable
- UHF
- Ultra High Frequency
- UL
- Useful Load
- ULD
- Unit Load Device
- UTC
- Co-ordinated Universal Time
- VAT
- Indicated Speed (V) At Threshold
- VDF
- VHF direction finding
- VDOP
- Vertical Dilution of Precision
- VFR
- Visual flight rules
- VHF
- Very High Frequency
- VL
- Variable Load
- VLF
- Very Low Frequency
- V1
- Take Off Decision Speed
- V2
- Lowest Take Off Safety Speed
- VFE
- Maximum speed with Flaps Extended
- VLO
- Maximum speed to Operate Landing gear
- VMC
- Visual Meteorological Conditions
- VMCA
- Minimum Control Speed in the Air
- VMCL
- Minimum Control Speed in the Landing configuration
- VMO
- Maximum Operating Speed
- VMU
- Minimum Unstick Speed
- VNAV
- Vertical Navigation
- VOLMET
- Meteorological Information for Aircraft in Flight — literally VOL ("fly" in French) MET (meteorology)
- VOR
- VHF Omnidirectional Range
- VP
- Vapour Pressure
- VR
- The speed at which the aircraft is rotated to lift off from the runway
- VRB
- Variable
- VREF
- Reference Landing Speed
- VS
- Stalling Speed
- VSI
- Vertical Speed Indicator
- VSR
- Reference Stalling Speed
- W/V
- Wind Velocity
- WAAS
- Wide Area Augmentation System
- WAFC
- World Area Forecast Centre
- WGS84
- World Geodetic System 1984
- WIP
- Work In Progress
- WMO
- World Meteorological Organisation
- WS
- Wind Shear
- WV
- Water Vapour
- WVC
- Water Vapour Content
- XTD
- Cross Track Distance
- Z
- Coordinated Universal Time
- ZFM
- Zero Fuel Mass
- λ
- Wavelength. The symbol is the greek letter lambda