Glossary of Aviation Terms

Please select a letter from below. You will then be presented with a list of aviation terminology beginning with that letter.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

FAA - Federal Aviation Administration, USA, equivalent of UK's CAA.

FAA - Fleet Air Arm, of UK's Royal Navy.

FADEC - full authority digital engine control.

FAF - final approach fix, the point at which a published instrument approach begins.

FAI - Fédération Aéronautique Internationale, the international body for verification of aeronautical record attempts and sporting regulations.

FAR - Federal Aviation Regulations (USA).

FARA - Formula Air Racing Association.

FBL - fly by light i.e. control via optical fibres

FBO - fixed base operator, American term for commercial operators supplying fuel, maintenance, aircraft sales, rental, flight training, handling and other GA services at an airport. (So called because the first FBOs were early barnstormers who chose to settle at one field.)

FBW - fly-by-wire. Aircraft control systems in which pilots' control inputs are transmitted to control surfaces electronically or via fibre optics rather than by mechanical linkage. Also see FBL.

FCL - Flight Crew Licensing (Division), a CAA department handling all aspects of private and professional pilot, flight engineer and navigator licensing.

FCS - flight control system.

fcst - forecast.

FDR - flight data recorder, popularly known as a 'black box' (actually painted bright orange), by which various parameters of an aircraft's flight performance are recorded for analysis in the event of an incident or accident.

feather (of a propeller) - to set the angle of CS or VP propeller edge on to the airflow to minimise drag and rotation following engine failure on multi engined aircraft. Also applies to motor gliders which have feathering propellers to enhance engine off soaring performance.

FIC - Flight Information Centre.

final(s) - final approach. The part of a landing sequence or aerodrome circuit procedure in which the aircraft has made its final turn and is inbound to the active runway. Downwind is the segment of the circuit paralleling the runway and flown on a reciprocal heading. Base leg is the crosswind segment bringing the aircraft from the downwind leg to final approach. The leg before downwind is called the Crosswind leg.

FIR - Flight Information Region. UK airspace is divided into two FIRs, London and Scottish.

FIS - Flight Information Service, providing a variety of services and information (but not control) to air traffic in the two FIRs above.

FJ - fast jet.

FL - flight level, a level of constant atmospheric pressure shown by an altimeter set to a standard 1013.2 millibars, expressed in rounds hundreds of feet, thus FL330 is 33,000 feet.

flag - warning signal incorporated in certain navigation and flight instruments indicating that the instrument is not operating satisfactorily or that the strength of signals being received from ground stations is below acceptable limits.

flameout - combustion failure in a turbine engine resulting in power loss.

flat rating - throttling or other restriction of engine power ouput (usually in turboprops and turboshafts) at sea level to enable it to give constant predictable power at higher operating altitudes.

FLG - flashing.

flicker effect - nausea, dizziness or vertigo which can be brought on by flickering at certain frequencies of a bright light source such as sunlight or strobe when viewed through a rotating propeller or rotor blades.

Flight plan codes -
1. Nav/com codes
D = DME
G = GLS
L = ILS
O = VOR
V = VHF R/T
S = V+O+L+ADF
2. Transponder codes
N = None or unserviceable transponder
A = Mode A, no altitude reporting, 4096 codes
C = Mode C, altitude reporting, 4096 codes
S = Mode S, altitude and aircraft identification.


FLIR - forward-looking infra red

FLM - foot launched microlight.

FM - frequency modulation.

FMC/S - flight management computer/system

FMGC - flight management guidance computer.

FMS - flight management system.

FMU - flight management unit.

FOD - foreign object damage, usually to turbine engines through ingestion of runway debris etc.

FPL - filed flight plan.

fpm - feet per minute, a measure of an aircraft's rate of climb or descent. Similarly m/s or mps, metres per second.

FSS - Flight Service Station (USA).

FTO - flying training organisation.