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
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
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
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
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
flat rating - throttling or other restriction of engine power output (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.