Aviation Glossary A-M

Aircraft and Aviation Terms Definitions (Not in any particular order)
AAIB Air Accident Investigation Branch: British equivalent of NTSB
ACARS Aircraft Communications Addressing and Reporting System
ACAS Aircraft Collision Avoidance System
ADF Automatic Direction Finder: a navigation receiver
ADS-B Automatic Dependent Surveillance: Broadcast
Altitude Indicator Indicates aircraft altitude or height from sea level. Must be calibrated for local atmospheric pressure.
Attidtude Indicator (Artificial Horizon) Shows if aircraft is in level flight. Usually indicated by wings on a horizontal line.
APU Auxiliary Power Unit
ATC Air Traffic Control
ATIS Automated Terminal Information Service
CTAF Common Traffic Advisory Frequency
DME Distance Measuring Equipment
EPIRB Emergency Position Indicating Radio Beacon
Flight Plan Aircraft will follow this route. Can contain multiple legs. Sumbmitted before flight.
Flight Planned Route Aircraft follows the FLIGHT PLAN there may be minor deviations but aircraft eventually resumes the FLIGHT PLANNED ROUTE.
FLIR Forward Looking Infra-Red (radar)
FMC Flight Management Computer
GNSS Global Navigation Satellite System
Go Around Aborted landing. Wheels do not contact with the ground. Aircraft climbs away under power.
GPS Global Positioning System.
GPWS Ground Proximity Warning System
GS Ground Speed. Calculated from speed indicator adjustment.
HF High Frequency (Radio) 3mHz to 30mHz
IAS Indicated Air Speed. Usually diminishes with altitude. (See Ground Speed).
ICAO International Civil Aviation Organization: agency of the UN
ILS Instrument Landing System
IMC Instrument Meteorological Conditions (see IFR)
Inmarsat International Maritime Satellite Organization
INS Inertial Navigation System
KT Knots: nautical miles/hour
LOC Localizer: part of Instrument Landing System (ILS). Located on ground at far end of runway. Provides runway centreline information to aircraft

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M Mach number: speed of a/c expressed in relation to speed of sound