DA Drift angle
DADC Digital air-data computer
DAMPED FREQUENCY The frequency of oscillation of an under damped second-order filter; See Also: second-order filter; Symbols: omega; Typical Units: rad/s, Hz; Dimensio...
DAMPING RATIO Control parameter for a second order filter. Symbols: zeta;
DAP Decision Altitude
DARTBOARD Ground-based interference from "ASPIDISTRA" of enemy RT and WT channels in the 300 kHz band.
DATA SOURCE OBJECT (DSO) Software that receives data from a physical device, translates the data into standard units, maintains equipment status, and provides a common interfa...
DATA TRANSFER SYSTEM Total pressure
DATA TRANSFER SYSTEM (DTS). A device for transferring data with avionics, similar to a diskette drive;
DB Decibel
DC Dual Control
DCA Directorate of Civil Aviation
DCT direct
DEAD RECKONING (DR) A method of navigation based on basic information (barometric altitude, magnetic heading, airspeed, wind conditions) from best available source; somet...
DEAD STICK A term used to describe unpowered flight (glide) when the engine quits running.
DECISION HEIGHT with respect to the operation of aircraft, means the height at which a decision must be made, during an ILS or PAR instrument approach, to either cont...
DECISION HEIGHT (DH) With respect to the operation of aircraft, means the height at which a decision must be made during an ILS, MLS, or PAR instrument approach to either ...
DECKER Phosphorous coated rags transported in water and designed to fire crops and forests. This tactic was of little effect.
DEG Degrees
DEL Delay/delayed
DELAY Delays are incurred when any action is taken by a controller that prevents an aircraft from proceeding normally to its destination for an interval of ...
DELTA Difference; error.
DEP Departure
DEPART FROM HOVER (DHOV) A guidance mode providing lateral guidance, longitudinal guidance and vertical guidance for a set heading or bank angle, a set speed, and a set climb ...
DEPARTURES The number of aircraft take-offs actually performed in domestic and international scheduled and non-scheduled passenger/cargo and all-cargo revenue se...
DERIVATIVE Rate of change, usually with respect to time; Symbols: x dot, x prime, x sup (1), dx/dt, Dx;
DERIVED Calculated values for which no direct measurement exists; Compare: estimated, filtered, measured, raw, selected, smoothed
DESALT Desired altitude
DESIRED What must be achieved in order to match a plan; Synonyms: reference;
DESIRED ALTITUDE (DESALT) A guidance control law parameter, generated by the vertical guidance modes; altitude which controlled altitude is attempting to achieve Typical Units:...
DESIRED PATH A trajectory in space determined by guidance to meet the current mission objectives;
DESIRED SPEED (DESS) A guidance control law parameter, generated by the longitudinal guidance modes; speed which controlled speed is attempting to achieve Typical Units: f...
DESS Desired speed
DEV Deviation
DEVIATION Difference from desired;
DEVICE A piece of equipment, a subsystem; Synonyms: physical device, unit
DF Direction Finder
DFAD Digitized Feature Analysis Data
DFS Deutsche Flugsicherung AG
DG Directional gyro
DGNSS Differential GNSS
DGPS Differential global positioning system. LA- prefix refers to local area DGPS; WA- prefix refers to wide-area DGPS signal retransmission schemes.
DGT REN Differential GPS
DH Decision Height
DHOV Depart from hover
DIALED IN Slang term for the condition in which the aircraft is set up to fly smoothly and predictably. This is the state where the mechanics and electronics wo...
DIFFERENCE EQUATION Distance Measuring Equipment
DIFFERENT EQUATION A mathematical relationship to model a continuous function, expressed in terms of derivatives; Initial conditions are usually given or implied. In avi...
DIGITAL MAP GENERATOR (DMG) Digital equipment that produces map video, and sometimes contains TRN; uses Digital Terrain Elevation Data and Digitized Feature Analysis Data; Displa...
DIGITAL TERRAIN ELAVATION DATA(DTED) On a digital map, data for elevation of terrain; DTED is usually provided by Defense Mapping Agency; Compare: Digitized Feature Analysis Data;
DIGITIZED FEATURE ANALYSIS (DFAD) On a digital map, data for cultural features such as buildings and roads; DFAD is usually provided by Defense Mapping Agency; Compare: Digital Terrain...
DIGITZER Any electronic device capable of converting information to a digital format; usually refers to encoding devices that convert sensed altitude into a tr...
DIHEDRAL The V-shaped bend in the wing. The upward angle of the airplane`s wings with respect to the horizontal. Typically, more dihedral causes more aerodynam...
DIMENSIONLESS No units, such as ratios; Synonyms: unit less;
DINA An American improvement of MANDREL airborne jamming device operating in the 95-210 MHz band. Also named PIPERACK when used to counter FuG 220 AI radar...
DING Minor dent or damage to the structure. Also, a nick in a prop. Dinged props must be replaced.
DIRECT Towards a point along the shortest distance; Compare: course
DIRECTION bearing.
DIRECTIONAL STABILITY The tendency of an aircraft to keep flying the direction its pointed.
DIRTY Extension of gear, hook, flaps, etc. for slow speed flight or landing.
DIRTY UP Extension of gear, hook, flaps, etc. for slow speed flight or landing.
DISCRETE TIME Time divided into quantized intervals; in avionics, time is usually divided into equal intervals to create a periodic process; Compare: continuous tim...
DISCRETE-TIME EQUATION A mathematical relationship to describe a function of time, expressed in terms of discrete time; Compare: continuous-time equation, difference equatio...
DISTANCE Method of measurement dependent on use; Synonyms: range;
DISTANCE MEASUREING EQUIPMENT(DME) Equipment for measuring distance, usually from an aircraft to a ground station; usually part of a Tactical Air Navigation system
DISTRESS A condition of being threatened by serious and/or imminent danger and of requiring immediate assistance.
DITCH To land safely somewhere other than a runway.
DIVERT To change from a scheduled landing base to an alternate airfield.
DLA Delay (Message of an ICAO FPL)
DME Distance Measuring Equipment.
DMG Digital Map Generator
DNS Doppler Navigation System
DOF Distance Measuring Equipment
DOMESTIC OPERATIONS Operations within and between: the 50 states of the United States, the District of Columbia, the Commonwealth of Puerto Rico, and the United States Vi...
DOP Dilution of Precision (GPS)
DOPPLER A technique for measuring velocity by radiating and determining frequency shift
DOPPLER NAVIGATION SYSTEM (DNS,DPLR) A navigation for measuring velocity by radiating and determining frequency shift;
DORSAL FIN An extension of the vertical fin forward of the main part of the fin, and against the fuselage. On the top, or "dorsal" side of the aircraft.
DOWN THRUST Downward angle of the engine relative to the centerline of the airplane. Down thrust helps overcome the normal climbing tendency caused by the torque ...
DP Deal Pending
DPLR Doppler navigation system
DR Ded (deduced) reckoning.
DRAG Force created by an airfoil moving through atmosphere, opposite to the direction of motion. The air resistance to forward motion. Drag can be increase...
DRIFT Slow, monotonic change in measured data
DRMS Distance root mean squared.
DRUMSTICK Ground based interference with enemy WT transmissions in the 3-6 MHz bands
DSO Data source object
DSP Data Processing
DTED Digital Terrain Elevation Data
DTK Desired track
DTU Data transfer unit
DUAL RATES Radio function used to adjust control sensitivity.
DUAT Direct User Access Terminal (US Computer Self-Briefing system)
DUNKEL-NACHTJAGD - DARK NIGHT HUNT; German night fighter zone not backed by searchlights
DUPLES Separate channels for transmitting and receiving
DœPPEL The German version of WINDOW. Strips of silver paper dropped to confuse the ground radars
E Airspace ICAO Class E
EAA Experimental Aircraft Association
EAD European AIS Database
EAG European ATFM Advisory Group
EANPG European Air Navigation Planning Group (ICAO)
EARLY EXTENDED VALIDATION INTEGRATIONPROGRAM (EEVIP) An FAA program, first implemented for the Boeing 777, to give "out-of-the-box" ETOPS clearance to a new plane, rather than waiting for a couple of yea...
EAROM Electrically alterable read-only memory, a type of digital memory device.
EART-REFERENCED FLIGHT PATHANGLE Angle in vertical plane of airspeed vector and groundspeed vector; usual definition for flight path angle; Compare: air-mass flight path angle; Symbol...
EARTH COORDINATES Coordinates referenced to the earth; See Also: east-north-up; Compare: body coordinates, stability coordinates
EARTH DATA Environmental data related to the earth at some point of interest; usually a function of latitude and longitude
EARTH ECCENTRICITY A measure of the degree to which the earth is oblate; Symbols: epsilon;
EARTH MODEL The earth model computes data related to the earth. Most data is a function of position. Standard models are: International, Clarke 1866, Clarke 1880,...
EARTH RADIUS Radius of the earth, function of position, separate radii for longitudinal radius and for lateral radius; See Also: state data; Symbols: rho; Typical ...
EARTH RADIUS BEST SPHERE Gaussian radius of curvature
EARTH RADIUS EAST/WEST Prime radius of curvature
EARTH RADIUS NORTH/SOUTH Meridian radius of curvature
EARTH SPEED Total velocity measured with respect to a plane tangent to the earth`s surface at the current position; a vector composed of velocity north, velocity ...
EAS European Air Sports
EASA European Aviation Safety Authority (planned to replace JAA)
EAST-NORTH-UP (ENU) A standard earth coordinate frame and sign convention, where east, north, and up are positive; vertical, or V, is sometimes used in place of up; Synon...
EAST-NORTH-VERTICAL (ENV) East-north-up.
EATCHIP European Air Traffic Control Harmonization Implementation Project
EATMP European Air Traffic Management Plan
EATMS European Air Traffic Management System
EATS Empire Air Training Scheme
EBAA European Business Aviation Association
EC European Commission
ECAC European Civil Aviation Conference ("Association" of Europe`s CAAs)
ECI Earth Centered Inertial
ECM Electronic Counter-Measures.
ECOGAS European Council of General Aviation Support
EDF Electric ducted fan. A battery-powered fan (rather than exterior propeller) driven aircraft.
EEC Euro control Experimental Centre
EEPROM Electrically Erasable Programmable Read-Only-Memory
EET Estimated Elapsed Time
EFATO Engine Failure At Take-Off (JAR-FCL)
EFDP European Flight Data Processing
EFIS Electronic Flight Instrument System
EFTS Elementary Flying Training School
EGNOS European Geostationary Navigation Overlay System
EGT Exhaust gas temperature indicator.
EHS Enhanced Surveillance (Mode S, 2nd step)
EHSI Electronic Horizontal Situation Indicator
EICAS Engine indicating and crew alerting system.
ELBA Emergency Locator Beacon-Aircraft
ELECTRIC STARTER A hand-held electric motor used for starting a aircraft airplane engine. Usually powered by a 12-volt battery.
ELEV Elevation
ELEVATION An angle in the vertical plane through a longitudinal axis; height above mean sea level, usually of terrain;
ELEVATOR Pitch control. Causes the aircraft to raise or lower its nose, resulting in a climbing or diving response. Moving the elevator down causes the tail to...
ELT Emergency Locator Transmitter (crash-activated transmitter)
EMC EATMP Management Committee
EMIL ; Nickname for the Bf109E
EMPENNAGE The vertical and horizontal tail surfaces of an airplane.
EN ROUTE AIR TRAFFIC CONTROLSERVICES Air traffic control services provided aircraft on IFR flight plans, generally by centers, when these aircraft are operating between departure and dest...
ENCAL Encoding Altimeter
ENCODER Displays aircraft`s altitude on ground-based radar screens.
ENGINE The methanol or gasoline fueled power plant used in a aircraft. Two or four-stroke gasoline and glow engines are very popular in aircraft. Four-stroke...
ENGINE COWL A removable covering placed over and around an airplane`s engine.
ENPLANEMENT A revenue passenger boarding an aircraft.
ENPRM Euro control (European?) Notice of Proposed Rule Making
ENU East-north-up
ENV East-north-vertical
ENVIRONMENTAL DATA Atmospheric data and earth data
EOBT Estimated off-block time
EP European Parliament
EPOXY A two-part resin/hardener glue that is extremely strong. It is generally available in 6 and 30-minute formulas. Used for critical points in the aircra...
EQUIPMENT STATUS Operational status of a piece of equipment consisting of a status indicator and status words; Synonyms: health;
ERA European Regional Airlines Association
EROS Brand Name for Oxygen Mask
ERPROBUNGS GRUPPE Luftwaffe formation for the evaluation of new tactics or techniques
ERROR Difference between desired and measured data; Synonyms: delta;
ESA European Space Agency
ESC Economic Social Committee
ESTIMATED Data that is the result of filtering two or more signals; Compare: derived, filtered, measured, raw, selected, smoothed
ETA Estimated Time of Arrival. The time the flight is estimated to arrive at its destination.
ETD Estimated Time of Arrival
ETFMS Enhanced Tactical Flow Management System
ETOPS Extended Twin-engine operations. FAA designation of over-ocean flights far from possible emergency landing strips, in which the possibility of engine ...
ETSI European Telecommunication Standardization Institute
EU European Union
EUAPA European Union Airplane Pilots Association
EULER ANGLES Pitch, roll, and yaw
EULER PARAMETERS Four parameters for specifying quaternion; Symbols: e sub
EUR European Region
EUROCAE European Organization for Civil Aviation Equipment
EVEREST A standard model for computing earth data
EXPANDED SCALE VOLTMETER (ESV) Device used to read the battery voltage of the on- board battery pack or transmitter battery pack.
EXPANDIG SQUARE SEARCH A pattern of progressively larger squares (a "square spiral") followed for searching the ground from an aircraft; Compare: creeping line search, secto...
EXPEDITE Used when prompt compliance is required to avoid the development of an imminent situation.
EXPONENTIAL This radio function allows the air crafter to adjust the sensitivity of the control towards the center. This will make the small stick motions very pr...
EXTENDED OVER-WATER OPERATION 1) With respect to aircraft other than helicopters, an operation over water at a horizontal distance of more than 50 nautical miles from the nearest s...
EXTERNAL-LOAD ATTACHING means the structural components used to attach an external load to an aircraft, including external-load containers, the backup structure at the attach...
EXTROPOLATE Function to determine values from two or values in a table, when the given value lies outside of the range of the table; usually linear but can be hig...
F Airspace ICAO Class F
FA Area Forecast (Meteo)
FAA Federal Aviation Administration.
FADEC Full authority digital engine control.
FAF Federal Aviation Administration
FAILSAFE A PCM function which moves servos to a pre programmed position if transmitter signal is lost or corrupted.
FAIRING A shaped area used to smooth out, streamline, or "fair", the joint between two members of an airplane to reduce drag. A wing fairing joins the wing an...
FANS Future Air Navigation System (an ICAO project group)
FAR Federal Aviation Regulations. The laws under which airmen in the US fly.
FAR 36 NOISE LEVELS In order to meet FAR 36 Stage 3 requirements, the maximum noise level permitted is: *Take Off 89.0 EPNdB *Sideline 94.0 *Approach 98.0
FAWP Final Approach Waypoint
FBO Fixed Base Operator
FBO (FIXED BASE OPERATOR) The small but important building near the ramp and runways of a small airport, from which airfield activity is coordinated.
FCC Federal Communications Commission (USA)
FCL Flight Crew Licensing
FCM Flight Confirmation Message
FCS Flight control system
FD Winds and Temperature aloft Forecast
FDE Fault detection and exclusion (GPS)
FDP Flight Data Processing
FDR Flight Data Recorder
FDS Flight Director System
FE Flight Examiner
FEDERAL AVIATION REGULATION(FAR) 14 CFR FAR Part 91 - General Aviation (portions apply to all operators) 14 CFR FAR Part 103 - Ultra light Vehicles 14 CFR FAR Part 105 - Parachute Jum...
FERRY FLIGHT A flight for the purpose of: 1. Returning an aircraft to base. 2. Delivering an aircraft from one location to another. 3. Moving an aircraft to and fr...
FFAS Free Flight Air Space (Euro control Definition)
FFON Flight Phone
FI Flight Identity (Code) - (Mode S Transponder)
FIC Flight Information Center
FIDGET Interference of enemy high frequency night-fighter transmissions.
FIE Flight Instructor Examiner
FIELD CHARGER A fast battery charger designed to work from a 12-volt power source, such as a car battery.
FIGURE 9 Can be an "official" competition maneuver, or a badly-done loop. When the aircraft flies over the top of a loop and picks up too much speed, the momen...
FILTER A device to alter a signal; software to alter a data steam; See Also: averaging filter, band-pass filter, complementary filter, first-order filter, hi...
FILTERED Data that is the result of filtering a signal; filtering is usually more sophisticated than smoothing Compare: derived, estimated, measured, raw, sele...
FIN, VERTICAL FIN The fixed portion of the vertical tail surface.
FINAL Used to mean an aircraft is on proper heading, descent rate, airspeed, and altitude during runway approach prior to landing, or to a target prior to w...
FIO Flight Information Office
FIR Flight Information Region
FIRE RESISTANT (1) With respect to sheet or structural members means the capacity to withstand the heat associated with fire at least as well as aluminum alloy in di...
FIREPROOF (1) With respect to materials and parts used to confine fire in a designated fire zone, means the capacity to withstand at least as well as steel in d...
FIRST-ORDER FILTER-ORDER FILTER A filter in which the output follows the input, only more slowly; It is usually implemented in software as a difference equation of period T. The firs...
FIS Flight Information Service
FIS-B Flight Information Service-Broadcast
FISHPOND Device fitted to H2S to enable wireless operators to scan beneath the bombers for night fighter attacks from below.
FIX A determination of one`s position based on external data, such as a known terrain point
FIXED WING An airplane, as opposed to a rotary wing / helicopter;
FL Flight Level, Altitude x100 = feet AMSL (FL 70 = 7000ft) at ISA
FLAK Flieger Abwehr Kanonen. German anti-aircraft guns
FLAME RESISTANT means not susceptible to combustion to the point of propagating a flame, beyond safe limits, after the ignition source is removed
FLAMMABLE with respect to a fluid or gas, means susceptible to igniting readily or to exploding
FLAP EXTENDED SPEED means the highest speed permissible with wing flaps in a prescribed extended position
FLAPS Hinged control surface located at the trailing edge of the wing inboard of the ailerons that act together to increase the lift characteristics of the ...
FLARE The point during the landing approach in which the pilot gives an increased amount of up elevator to smooth the touchdown of the airplane. This maneuv...
FLASH RESISTANT means not susceptible to burning violently when ignited
FLENSBURG ; (FuG 227) German air interception homing device.
FLGHT PATH ANGLE (FPA) Angle in vertical plane of earth speed vector and groundspeed vector (usual definition), earth-referenced flight path angle; angle in vertical plane o...
FLIGHT BOX A special box used to hold and transport all equipment used at the flying field.
FLIGHT CONTOLS Controls in a cockpit for flying an aircraft; primary flight controls are wheel, yoke, cyclic, pedals, throttle, and collective; secondary flight cont...
