FLIGHT CONTROL SYSTEM (FCS) A primary flight control system or an automatic flight control system;
FLIGHT DATA RECORDER (FDR) An electronic device that records aircraft maneuvers. Used in accident investigations.
FLIGHT DIRECTOR System, usually software, that generates stick position cues from state errors - typically three cues:. pitch, roll, and throttle for fixed-wing and l...
FLIGHT LEVEL (FL) A level of constant atmospheric pressure related to a reference datum of 29.92 inches of mercury. Each is stated in three digits that represent hundre...
FLIGHT PACK OR AIRBORNE PACK All of the radio equipment installed in the airplane, i.e., Receiver, Servos, Battery, Switch harness.
FLIGHT PHONE Air-to-ground telephone system.
FLIGHT PLAN Specified information relating to the intended flight of an aircraft that is filed orally or in writing with an FSS or an ATC facility.
FLIGHT SERVICE STATION (FSS) Air traffic facilities which provide pilot briefing, enroute communications and VFR search and rescue services, assist lost aircraft and aircraft in e...
FLIGHT VISIBILITY means the average forward horizontal distance, from the cockpit of an aircraft in flight, at which prominent unlighted objects may be seen and identif...
FLIGHTCREW MEMBER means a pilot, flight engineer, or flight navigator assigned to duty in an aircraft during flight time. "Flight level" means a level of constant atmos...
FLIGHTLINE Where aircraft are parked between missions.
FLIR Forward-Looking Infrared
FLOATS Long, canoe-shaped structures that allow an airplane to land on water. They are not a part of the aircraft structure, but suspended below the fuselage...
FLOS Forward Looking Infra-Red
FLOWER an intruder sortie, usually by Mosquitoes, against German night-fighter airfields during bomber operations.
FLT Flight
FLUTTER A phenomenon whereby the elevator or aileron control surface begins to oscillate violently in flight. This can sometimes cause the surface to break aw...
FLUX VALVE A device to measure the earth`s magnetic flux; a compass
FLY OVER A position update by flying directly over a known point
FLYING BOAT The type of aircraft where the fuselage has the lower portion shaped like a power boat. The plane lands on water directly onto the fuselage. There may...
FM Frequency Modulation. This describes the mode of transmission of radio signal from transmitter to receiver.
FMCS Flight management computer system.
FMD Frequency Modulation
FMS Flight Management System
FNPT Flight Management System
FOCA Federal Office for Civil Aviation (Swiss CAA - see BAZL)
FOD Foreign Object Damage
FOG Fiber-optic gyro.
FORE, FORWARD Towards the front. Used such as: "...the forward edge of the rib...", or as in: "...with fore and aft movement...."
FOREIGN AIR CARIER means the carriage by aircraft of persons or property for compensation or hire, or the carriage of mail by aircraft, or the operation or navigation of...
FOREIGN AIR CARRIER means any person other than a citizen of the United States, who undertakes directly, by lease or other arrangement, to engage in air transportation
FOREIGN AIR TRANSPORTAION means the carriage by aircraft of persons or property as a common carrier for compensation or hire, or the carriage of mail by aircraft, in commerce b...
FORWARD ELEVATION A control surface used to tilt an airplane up or down and mounted on the front rather than the rear of an airplane.
FORWARD-LOOKING INFRARED (FLIR) Sensor equipment used to supplement AGR, extend the aircraft visual search capability and provide position information for guidance and navigation upd...
FPA Flight path angle
FPL Flight Plan (for ATC)
FPM Feet Per Minute. Unit of measure, used for ROC or sometimes speed.
FREEDOM OF INFORMATION ACT (FOIA) The Freedom of Information Act (FOIA) allows all U.S. citizens and residents to request any records in possession of the executive branch of the feder...
FREIJAGD The use of Bf109s in independent, (usually high altitude), fighter sweeps over southern Britain to divert Fighter Command`s response.
FREQUENCY CONTROL The FCC has allowed the 72MHz (72.010 - 72.990) band to be used for R/C aircraft operations. This band is divided up into many different channels in w...
FREYA :;; (FuG 221) A series of German early warning long range radars.
FSDM feet per minute (vertical speed)
FSDO Flight Standard District Office (FAA USA)
FSS Flight Service Station
FT feet (approx 0.3 Meters)
FTD Flight Training Device (lower category "simulator")
FTO Flight Training Organization (Flight School)
FUA Flexible Use of Airspace
FUEL The methanol/nitro methane/lubricant mix used to fuel aircraft engines. A helicopter fuel mix has a higher concentration of lubricant to counter the l...
FUG (FUNK GER¤T) a series of airborne homing devices used to illuminate MANDREL, MONICA, H2S and ASV. Later modifications permitted their use as search radars for nigh...
FULL DE-ICE Complete anti - and/or de-ice equipment installed on wings, tail, props, and windshield.
FULL PANEL All gyros necessary for instrument flight.
FUSE Fuselage, main body
FUSELAGE The body of an airplane.
FVS Fliegerische Vor-Schulung
G Acceleration force unit (1G = Earth Gravity
G-H British two-station radio direction finding system used as a bombing aid
G/S Glide slope receiver and indicator.
G/S SEL Groundspeed select
GA Go around
GA General Aviation and Aerial Work (all non-commercial civil aviation)
GAC General Aviation Center
GAFOR General Aviation Forecast (Weather)
GAIN Gyro sensitivity. When too low, the tail will not hold position well. When too high, the surface being dampened by the gyro will tend to wag, or hunt ...
GAL Gallons (usually US 3.78 liter, may be Imperial 4.54 liter)
GALLEY On-board meal service equipment.
GAMA General Aviation Manufacturers Association (USA)
GARDENING RAF codeword for mine laying by aircraft
GAS DISCHARGE A type of luminescent digital display.
GASSER Slang for a aircraft using a gasoline engine as a power plant.
GAT General Air Traffic
GATT General Agreement on Trade and Taxes
GAUSSIAN RADIUS OF CURVATURE Radius of the earth for the best fitting sphere at a given position; Synonyms: earth radius best sphere; Symbols: rho sub G; Typical Units: ft; Dimens...
GBAS Ground Based Augmentation System (DGNSS/DGPS/LAAS)
GCA Ground Controlled Approach ("Talk-down")
GCI Ground Communication Infrastructure
GCLP Guidance control law parameter
GCR Ground clutter rejection.
GEAR Landing gear, the undercarriage and wheels of an aircraft.
GEE RAF navigational aid which could provide the navigator with a fix from pulses transmitted by three ground stations. Range approximately 300 miles.
GEN General
GENDEC General Declaration Customs Form see full size, download zipped form,
GENERAL AVIATION That portion of civil aviation which encompasses all facets of aviation except air carriers holding a certificate of public convenience and necessity ...
GENERAL ELECTRIC (GE) Engine Mfr.
GEO Geostationary Earth Orbit (Satellite)
GEOCENTRIC LATITUDE Latitude measured with respect to horizontal through mass center of the earth; Compare: astronomical latitude, geodetic latitude; Symbols: Phi sub C; ...
GEODETIC LATITUDE Latitude measured with respect to normal to reference ellipsoid; Compare: astronomical latitude, geocentric latitude; Symbols: Phi sub T; Typical Unit...
GESCHWADER Luftwaffe formation approximately equivalent to a Wing, comprising 90-120 aircraft divided into Gruppen, each of 20-30 aircraft.
GFT General Flight Test (JAR-FCL)
GHZ Gigahertz (1`000 MHz or 1`000`000`000 Hertz)
GIMBALED INERTIAL SENSOR Accelerometers mounted to a platform which is free to rotate, with gyroscopes to measure rotation and servomotors to maintain a fixed attitude with re...
GISELA German intruder operation when the night fighters followed the British bombers back to their bases
GLD Glider
GLIDESCOPE Angle approach a runway; Symbols: Gamma; Typical Units: rad, deg;
GLITCH Momentary radio problem that never happens unless you are over trees or a swamp.
GLOBAL POSITIONING SYSTEM (GPS) A navigation sensor based on satellites; A Global Positioning System (GPS) provides highly accurate navigation data: position, velocity, and time refe...
GLONASS Global Orbiting Navigation Satellite System (Russian GNSS)
GLOW FUEL A Methanol based fuel, with a lubricating agent, used in most aircraft engines. Most aircraft fuels also use a percentage of nitro methane.
GLOW HEATER This is the plug that is used to help ignite the fuel in a aircraft engine. The combustion of the fuel in the engine keeps the element hot between cyc...
GLS GPS Landing System
GLU GNSS landing unit. Provides precision GPS guidance to the runway in Category III operations.
GM-P10 GM=Morocco, P10=Prohibited Area No. 10.
GND Ground
GNSS Global navigation satellite system.
GO AROUND (GA) A basic guidance mode, providing lateral guidance, longitudinal guidance and vertical guidance to climb then to accelerate, while maintaining a wings-...
GOLD CROWN Trade name owned by King Radio Corp.
GPA Groupe Parlementaire pour l`Aviation
GPADIRS Global positioning, air data, inertial reference system.
GPH Gallons (US) per hour
GPS Global positioning system
GPS-DNS Global Positioning System
GPS-INS GPS using INS
GPWS Ground Proximity Warning System
GRAS Ground Proximity Warning System
GRAVITATIONAL ACCELERATION Acceleration caused by the force of gravity; Symbols: g; Typical Units: ft/s-squared, g; Dimensions: Length / Time-squared;
GRAVITY Force exerted by gravity; gravity sometimes includes effects of the earth`s rotation; gravity is often treated as a constant, but for greater accuracy...
GRID NORTH Standard aviation term.
GRIVATION Symbols: nu sub g ; Typical Units: rad, deg;
GROSS-BATTERIEN Large batteries of German anti-aircraft guns.
GROUND AIR A/C unit to cool aircraft while on the ground.
GROUND EFFECT The cushion of air that the aircraft rides on when close to the ground. This will decrease the amount of elevator needed to maintain a constant altitu...
GROUND GROCER A jamming device used to interfere with FuG 202 and 212 AI radar
GROUND SPEED The speed of an aircraft relative to the surface of the earth.
GROUND TRACK ANGLE (GTA) Direction of ground speed vector with respect to true north; Synonyms: true track; Symbols: eta; Typical Units: rad, deg;
GROUND VISIBILITY prevailing horizontal visibility near the earth`s surface as reported by the United States National Weather Service or an accredited observer
GROUNDSPEED The speed over the ground; earth speed projected to a horizontal plane; Symbols: V sub g; Typical Units: kt, ft/s; Dimensions: Length / Time;
GROUNDSPEED SELECT (G/S SEL) A basic guidance mode, providing longitudinal guidance to an operator selected groundspeed;
GRUPPE subdivision of a geshwader, each group having 20-30 aircraft assigned
GS Groundspeed.
GSC Ground Speed
GSM General Standard for Mobile Communication (Mobile phones)
GTA Ground track angle
GTWO Gross Take off Weight
GUIDANCE System, usually software, that determines state errors of desired state minus current state, typically three states: heading, altitude, and speed;
GUIDANCE CONTROL PARAMETER (GCLP) One of several parameters for the guidance control laws, generated by individual guidance modes; See Also: altitude error scale factor, altitude integ...
GUSTAV Nickname for the Bf109G
GYRO A mechanical or electronic device which helps to stabilize the orientation of the aircraft by sensing rotation, and moving the appropriate servo to co...
GYRODYNE a rotorcraft whose rotors are normally engine-driven for takeoff, hovering, and landing, and for forward flight through part of its speed range, and w...
GYROPLANE A rotorcraft whose rotors are not engine-driven, except for initial starting, but are made to rotate by action of the air when the rotorcraft is movin...
GYROSCOPE (GYRO) An inertial device for measuring change of attitude (pitch rate, roll rate, and yaw rate); gyroscopes usually consist of a gimbled, rotating mass; gyr...
H Helicopter (JAR-FCL)
H24 Operating 24 hours
H2S ?
HACK An aircraft used for communications or recreational purposes.
HAPPY VALLEY ; RAF nickname for the Ruhr industrial area.
HB- Swiss nationality marks for aircraft registration
HDG Heading
HDG SEL Heading select
HEADER TANK This is a small fuel tank used in line between the main tank and the carburetor. The purpose of the header tank is to ensure that the fuel fed to the ...
HEADING Direction on a compass that aircraft is pointed, measured with respect to true north or magnetic north; Symbols: psi; Typical Units: rad, deg;
HEADING ERROR A basic output from guidance to flight director, indicating the difference between actual heading and desired heading; Symbols: DELTA psi; Typical Uni...
HEADING HOLD This describes a type of Gyro which senses rotation, and maintains direction. This is accomplished by sensing the rate of motion, and the time of moti...
HEADING LOCK Slang term for Heading Hold Gyro.
HEADING SELECT (HDG SEL) A basic guidance mode, providing lateral guidance to an operator selected heading (magnetic heading or true heading, again, operator selectable);
HEALTH Equipment status
HEINRICH German transmitter introduced to jam GEE.
HEL Helicopter
HELICOPTER A rotorcraft that, for its horizontal motion, depends principally on its engine-driven rotors.
HELIPORT an area of land, water, or structure used or intended to be used for the landing and takeoff of helicopters
HELLE NACHTJAGD ILLUMINATED NIGHT HUNT; German night fighter system backed by searchlights
HEO High Earth Orbit
HERTZ (HZ) Cycles per second, used to describe radio frequencies; usually with the prefix k for kilo (one thousand), M for mega (one million) or G for giga (one ...
HF High Frequency radio equipment.
HF COM High Frequency Communication.
HG High Frequency
HIGE Hover In Ground Effect
HIGH-PASS FILTER (HPF) A filter that allows frequencies above a cutoff frequency to pass while attenuating frequencies below the cutoff frequency;
HIMMELBETT FOUR POSTER BED; German radar-backed night fighter system.
HIRF High intensity radiated field.
HIRL High Intensity Runway Lights
HIS Horizontal Situation Indicator
HIT (OR TO BE HIT) Sudden radio interference which causes your aircraft to fly in an erratic manner. Most often caused by someone turning on a radio that is on your freq...
HITS Highway In The Sky (Flight/NAV display concept)
HJ Operating hours during daylight
HMI Human Machine Interface
HOGE Hover Out of Ground Effect
HOL Holidays (MON-TUE-WED-THU-FRI-SAT-SUN-HOL)
HOLD To maintain some aspect (s) of aircraft state, such as heading, airspeed, altitude, pitch
HOOK In the US Navy, a target cursor;
HORIZONTAL STABILIZER (STAB) The horizontal tail surface at the back of the fuselage which provides aerodynamic pitch stability to the airplane.
HOT START An engine which has been running will tend to remain hot for a short time. During this period, it is possible to restart the engine by turning the cra...
HOUGH A standard model for computing earth data
HOURS FLOWN The airborne hours in domestic and international scheduled and non-scheduled revenue service, computed from the moment an aircraft leaves the ground u...
HOVER The art of flying without moving. This can also be an illusion, depending on wind speed. For airplanes, this is a 3D maneuver also known as a "hanger"...
HOVER HOLD (HVR SYM) A basic guidance mode, providing lateral guidance and longitudinal guidance to maintain an operator selected north velocity and east velocity; if the ...
HP Horsepower
HPA High-power amplifier.
HPF High-pass filter
HQ Horsepower
HUD Heads-up display
HVR SYM Hover hold
HX Head-Up Display
HYDRAULIC LOCK Hydraulic lock happens when the engine becomes flooded with fuel, to the point where the piston cannot compress it in the combustion chamber. This can...
HYSTERESIS A function in which the algorithm for computing output changes at defined events or thresholds, such that output follows one path as input increases a...
IACA International Air Charter Association
IAF Initial Approach Fix
IAOPA International Council of Aircraft Owner and Pilot Associations
IAOPA-EUR IAOPA European Region
IAS Indicated airspeed
IAS-TFB Indicated Air Speed
IATA International Air Transport Association
IAWP Initial Approach Waypoint
IBC Ils Back Course
IBIT Initiated built-in-test
IC Interrogator Codes (II and SI codes)
ICAO International Civil Aviation Organization (a UN-Suborganisation)
ICD Interface Control Document
ID Identification
IDL Interface Definition Language
IDLE THRUST the jet thrust obtained with the engine power control level set at the stop for the least thrust position at which it can be placed
IDS Infrared Detecting Set
IFF IDENTIFICATION FRIEND OR FOE. Equipment carried by aircraft of both sides which issued a signal identifying it as friendly.
IFPS Integrated Flight plan Processing System of Euro control
IFPUV IFPS Validation System (offline Route Verification by Internet)
IFR Instrument Flight Rules ("all" weather operations rules) IG (al) Imperial Gallon (4,54 Liter)
IFR AIRCRAFT/IFR FLIGHT An aircraft conducting flight in accordance with instrument flight rules.
IFR CONDITIONS weather conditions below the minimum for flight under visual flight rules
IFR OVER-THE-TOP with respect to the operation of aircraft, means the operation of an aircraft over-the-top on an IFR flight plan when cleared by air traffic control t...
II Interrogator Identity (Code) - (Mode S Transponder)
IINTERSTATE AIR COMMERCE the carriage by aircraft of persons or property for compensation or hire, or the carriage of mail by aircraft, or the operation or navigation of aircr...
ILS Instrument Landing System. A precision instrument approach system, generally used to land at fields experiencing weather.
ILS APPROACH Instrument Landing System
ILS BACK COURSE (IBC) Operation of ILS in which the runway is approached in reverse direction, giving only lateral guidance; Compare: ILS Front Course;
ILS FRONT COURSE Operation of ILS in which the runway is approached in forward direction, giving lateral, longitudinal, and vertical guidance; sometimes called ILS Com...
IM Instrument Landing System
IMC Instrument Meteo Conditions (weather requiring IFR flight)
IMMELMANN A maneuver originally used to reverse direction in combat. The airplane noses up and over onto its back. It then rolls upright and continues in the di...
IN inch
IN-LINE ENGINE An engine in which the cylinders are mounted in a straight line or else in two, connected at an angle.
INCIDENCE The angle of one portion of a aircraft when compared to another portion of the aircraft. For example, if the stabilizer is perfectly parallel to the g...
INCIDENCE METER Used to measure the angle of attack of an airfoil, can be used to measure blade pitch, or paddle pitch.
INCIDENT An occurrence other than an accident associated with the operation of an aircraft, which affects or could affect the safety of operations.
INDICATED AIRSPEED "" means the speed of an aircraft as shown on its pitot static airspeed indicator calibrated to reflect standard atmosphere adiabatic compressible flo...
INDICATED AIRSPEED (IAS) The speed of an aircraft as shown on its pitot static airspeed indicator calibrated to reflect standard atmosphere adiabatic compressible flow at sea ...
INDICATED ALTITUDE The altitude as shown by an altimeter.
INERTIAL Based on inertia, such as with an INS or an AHRS
INERTIAL NAVIGATION SYSTEM (INS) A totally self-contained system which requires no information from outside references. Provides aircraft position and navigation information in respon...
INERTIAL NAVIGATION UNIT (INU) A self-contained Inertial Navigation System;
INFRARED DETECTING SET (IDS) Forward-Looking Infrared;
INHG inches of Mercury (unit of pressure)
INITIALIZATION A basic control to a data source from controls and displays for initializing a device. Initiated by power-on, operator, driver, or MC; During initiali...
INITIATED BUILT-IN-TEST (IBIT) Self tests running internal to a device initiated external to the device, usually an operator, causing the device to temporarily cease normal operatio...
INNER MARKER Innermost marker beacon on an ILS
INS Inertial Navigation System
INSTRUMENT means a device using an internal mechanism to show visually or aurally the attitude, altitude, or operation of an aircraft or aircraft part
INSTRUMENT FLIGHT RULE (IFR) A set of rules governing the conduct of flight under instrument meteorological conditions.
INSTRUMENT LANDING SYSTEM (ILS) Inertial Navigation System
INSTRUMENT METEOROLOGICAL CONDITIONS(IMC) Meteorological conditions expressed in terms of visibility, distance from clouds, and ceiling less than minima specified for visual meteorological con...
INSTRUMENT OPERATIONS Arrivals or departures of an aircraft in accordance with an IFR flight plan or special VFR procedures or an operation where IFR separation between air...
INSTRUMENTATION Hardware to measure and to monitor a system
INT Interior
INTAKE An air inlet on an aircraft. You can have a carburetor intake, cooling intake, air conditioning intake (on full-size aircraft), and so on. Named becau...
INTEGRATE To combine multiple systems; Also, to compute to integral of;
INTEGRATED AVIONICS COMPUTER(IAC) Central processor of a Honeywell integrated cockpit system.
INTEGRATED AVIONICS PROCESSINGSYSTEM (IAPS) Central processor of a colins integrated cockpit system
INTEGRATOR A function that integrates; Many types of integrators exist; in fact, they constitute entire books. Avionics software usually relies on rectangular, s...
INTERNATIONAL A standard model for computing earth data
INTERPOLATE Function to determine intermediate values from two or values in a table; usually linear but can be higher order; endpoints are either extrapolated or ...
INTERROGATION A request of data
INTERSTATE AIR TRANSPORTATION means the carriage by aircraft of persons or property as a common carrier for compensation or hire, or the carriage of mail by aircraft in commerce: (...
INTLIM Path integral limit
INTMAGLIM Altitude integral limit
INTRASTATE AIR TRANSPORTATION means the carriage of persons or property as a common carrier for compensation or hire, by turbojet-powered aircraft capable of carrying thirty or mor...
INTVAL Path integral value
INU Inertial Navigation Unit
INVALID An indication that data from a device is bad and cannot be trusted
INVERTED Flying upside down. Note that elevator and rudder seem to work backward from the ground, as elevator, aileron and rudder inputs are all based upon the...
IPG Inertial Navigation System
IPPL National (ICAO) Private Pilots License (AOPA internal abbreviation)
IR Instrument Rating
IRE Instrument Rating Examiner
ISA ICAO Standard Atmosphere
ITC Investment tax credit.
ITU International Telephone Union, refers to certain HF channels.
ITW Initial Training Wing (Ground School)
IVSI Instantaneous vertical speed indicator.
JAA Joint Aviation Authorities (CAA of Europe)
JABO (JAGDBOMBER) Bf 109s converted to carry 250Kg bombs and carry out nuisance raids. A very effective tactic.
JAGD GESCHWADER Luftwaffe day fighters
JAGDSCHLOSS Rotating long range early warning radar
JAR Joint Aviation Recommendation (as used in some JAA documents, reported false!)
JAR-1 JAR on Definitions and abbreviations
JAR-145 JAR on Approved Maintenance Organizations
JAR-147 JAR on Maintenance Training
JAR-22 JAR on Sailplanes and Powered Sailplanes
JAR-25 JAR on Large Airplanes
JAR-36 JAR on Aircraft Noise
JAR-APU JAR on Auxiliary Power Units
JAR-AWO JAR on All Weather Operations
JAR-E JAR on Engines
JAR-FCL JAR on Flight Crew Licensing
JAR-MED JAR on Medical
JAR-OPS JAR on Flight Operations
JAR-P JAR on Propellers
JAR-TSO JAR on Technical Standard Orders
JAR-VLA JAR on Very Light Airplanes
