JERK Rate of change of acceleration, either scalar or vector, often with subscripts such as ENU or XYZ to denote the coordinate frame; time derivative of a...
JET PROP Describes aircraft using turbine engines to drive propellers.
JET STREAM A migrating stream of high-speed winds present at high altitudes.
JET-A1 Jet Fuel type A1
JOSTLE British airborne jamming device to disrupt enemy RT transmissions.
JPPL JAR-FCL Private Pilots License (AOPA internal abbreviation)
JSA Joint Steering Assembly (JAA)
JUG Nickname for the P-47
JURG Joint User Requirement Group
K Airspace Euro control Project Class K (all traffic known)
KALMAN FILTER A filter for putting together multiple data sources, of different types, to return an estimate better than any one source;
KALTINT Altitude integral advantage.
KAMMHUBER-LI RAF nickname for the zonal system of air defense set up by General Joseph Kammhuber.
KAMPF GESHWADER; Luftwaffe Bomber wing
KIAS Knots Indicated Air Speed; IAS, in knots.
KINT Path integral gain
KIT A Kit is an unassembled aircraft, it arrives as packages of parts it must be assembled, as opposed to an ARF; Almost Ready to Fly, which is mostly pre...
KITE means a framework, covered with paper, cloth, metal, or other material, intended to be flown at the end of a rope or cable, and having as its only sup...
KLA Reference Acceleration Gain.
KNICKEBEIN German radio beam/beams used to guide bombers to their targets.
KNOT One nautical mile/hour, which is about 1.15 stature miles/hour.
KNOWN ICING FAA certified to fly into icing conditions.
KORFU (FuG 351) German ground radar often used to produce fixes on the bombers H2S equipment.
KOSIF knots Indicated Air Speed.
KPH Kilometers/hour
KPI Key Performance Indicator (KPI)
KT(S) knots true air speed (KT)
KTAE Track angle error gain (KTAE)
KTAS Knots True Air Speed (KTAS). TAS, in knots.
KVSF Velocity error scale factor (KVSF)
KXTKD Cross track deviation gain (KXTKD)
KXTKR Cross track deviation rate gain (KXTKR)
KZSF Altitude error scale factor (KZSF)
L-BAND A radio frequency between 890 and 1550 MHz.
LAAS Local Area Augmentation System (LAAS)
LAHSO Land And Hold Short Operation. (to cross intersecting runway).
LANDING GEAR (LG) The assemblies this includes the wheels and the wheel struts.
LANDING GEAR EXTENDED SPEED the maximum speed an aircraft can be safely flown while the landing gear is extended
LANDING GEAR OPERATION SPEED the maximum speed at which landing gear can be extended or retracted safely.
LANDING SKID The rail type landing equipment used aircrafts which have no wheels.
LAPLACE TRANSFORM A mathematical relationship to model. A continuing function in the complex frequency domain (S-plane). Laplace transforms are usually used by systems ...
LARGE AIRCRAFT Aircraft of more than 12,500 pounds. Maximum certificated takeoff weight
LASER IRS An inertial reference system getting angular rate information by measuring doppler shift between two counter-rotating light beams.
LASER OBSTACLE AVOIDANCE/TERRAINAVOIDANCE SENSOR (OA/TA) A sensor that warns for long, thin objects (IE: like wires); it has at least a 20deg x 30deg FOV. Itis both velocity tracked and pitch stabilized; it ...
LAT Latitude
LATERAL Related to latitude; across an aircraft left to right
LATERAL AXIS The axis about which an aircraft pitches, extending out along each wing.
LATERAL CONTROL The ability to make an airplane roll, or turn around its long axis, according to its pilot`s wishes
LATERAL CUE A cue to control heading; lateral cyclic cue See Also: wheel cue,
LATERAL CYCLIC A flight control operated by moving left or right with hand in rotary-wing aircraft, primarily to control roll (heading); controls differential pitch ...
LATERAL CYCLIC CUE A lateral flight director cue for rotary-wing aircraft, primarily to control heading, by changing roll; Compare: wheel cue; Symbols: Gamma sub "LAT"; ...
LATERAL GUIDANCE Calculations for the lateral axis of the appropriate guidance modes. The control law lateral axis input data are: Cross Track Deviation, Cross Track D...
LATERAL STABILITY Stability about an airplane`s longitudinal (nose to tail) axis.
LATITUDE Position on earth, north or south of the equator; See Also: astronomical latitude, geocentric latitude, geodetic latitude; Symbols: Phi; Typical Units...
LBA Luftfahrt-Bundes-Amt (German CAA)
LBST Pounds of static thrust
LCD Liquid-crystal display.
LDA Landing Distance Available
LDG Landing
LEADING AND TRAILING EDGES The foremost and rearmost edges of a wing.
LEADING EDGE (LE) The very front edge of the wing or stabilizer. This is the edge that hits the air first.
LEAN Refers to carburetor setting. When an engine is run too lean it will overheat, causing damage, and likely an in flight engine failure. Tuning a carbur...
LEAN RUN This happens when an engine develops a lean condition. Possible causes are improper tuning, improper fuel choice, fuel foaming due to excessive vibrat...
LED Light-emitting diode.
LEG A segment of a flight plan; flight path between two waypoints
LEO Low Earth Orbit
LF ADF Low Frequency Automatic Direction Finding
LFR low-frequency radio range.
LH Left-hand
LI-R5 LI=Italy, R5=Restricted Area No. 5
LICHTENSTEIN (FuG 212) German air interception radar
LICHTENSTEIN SN-2 (FuG 220) AI search radar effective at 2 miles
LIFT Force created by an airfoil moving through atmosphere, perpendicular to the direction of motion.
LIGHTER-THAN-AIR AIRCRAFT aircraft that can rise and remain suspended by using contained gas weighing less than the air that is displaced by the gas
LIMITER A filter that passes the input to the output, except that the output is limited to a minimum value and a maximum value; Compare: rate limiter;
LIRL Low Intensity Runway Lights
LLWAS Low Level Wind Shear Alert System
LLZ Localizer (approach system)
LMB Light marker beacon.
LMM compass locator at middle marker
LNAV Lateral navigation guidance.
LOAD FACTOR The ratio of a specified load to the total weight of the aircraft. The specified load is expressed in terms of any of the following: aerodynamic force...
LOADING a.k.a wing loading. The load placed on the airfoil of a flying machine. In the case of an aircraft, this would be wing loading. Typically found by div...
LOC Localizer receiver and indicator.
LOCALIZER (LOC) Part of ILS that provides lateral deviations from a preset course;
LOGBOOK A pilot`s record of his flying achievements, including flight time, takeoffs, landings, and maneuvers mastered.
LOM compass locator at outer marker.
LONG Lateral Navigation (GLS)
LONGITUDE Position on earth, east or west of the prime meridian; Symbols: lambda; Typical Units: rad, deg;
LONGITUDINAL Related to longitude; lengthwise along the center line of an aircraft forward
LONGITUDINAL AXIS The axis about which an aircraft rolls, extending from nose to tail.
LONGITUDINAL CUE A cue to control pitch; longitudinal cyclic cue See Also: throttle cue,
LONGITUDINAL CYCLIC A flight control operated by moving fore or aft with hand in rotary-wing aircraft, primarily to control pitch (speed); controls differential pitch of ...
LONGITUDINAL CYCLIC CUE A longitudinal flight director cue for rotary-wing aircraft, primarily to control speed, by changing pitch; Compare: throttle cue; Symbols: Gamma sub ...
LONGITUDINAL GUIDANCE Calculations for the longitudinal axis of the guidance modes. The control law longitudinal axis input data are: Reference Acceleration, Reference Acce...
LONGITUDINAL STABILITY The characteristic of returning to the trimmed angle of attack after a displacement.
LOOKS PER MINUTE Scanning or sweep rate of a weather radar antenna.
LOOP A vertical circle in the air. The plane noses up, keeps rotating until it`s on its back, and then comes down and around to describe a vertical circle ...
LOP Line of position.
LORAN LOng RANge version of GEE
LORAN(-C) Long Range Navigation
LORAN-C Hyperbolic grid navigation system based upon measured time differences (TD) from pulse transmissions.
LOW FREQUENCY AUTOMATIC DIRECTIONFINDING (LF ADF) Equipment that determines bearing to a radio station on a low frequency band, usually the standard AM band;
LOW-PASS FILTER (LPF) A filter that allows frequencies below a cutoff frequency to pass while attenuating frequencies above the cutoff frequency; See Also: first-order filt...
LPF Low-pass filter
LRT Long range fuel tanks.
LRU Line replaceable unit
LS-D12 LS=Switzerland, D12=Danger Area No. 12
LSC Local Signaling Channel (VDL-4)
LT Local Time
LTE Long Term Exception (JAR-FCL)
LUBRICANT The agent used to aid in the reduction of friction between two parts. This term is used for many substances, which in turn are used in many different ...
LUFTWAFFE-HELFERINNEN . "BLITZ MAIDENS";. German female radar plotters.
LYC Avco-Lycoming (Engine mfr.)
M means mach number.
M$ Mega dollars (1`000`000 US dollars)
MAA maximum authorized IFR altitude.
MAC Mean Aerodynamic Chord
MACH NUMBER Ratio of airspeed to the local speed of sound (Mach 1 is the speed of sound under current atmospheric conditions); Symbols: M;
MAGNETIC VARIATION (MVAR, MAGVAR) Difference between true north and magnetic north, varying with position; magnetic variation drifts with time; Symbols: nu; Typical Units: rad, deg;
MAGNETING HEADING Heading of the aircraft relative to magnetic north; A Magnetic Heading Sensor provides this heading data. Symbols: psi sub M; Typical Units: rad, deg;...
MAGVAR Magnetic variation
MAHMOUD RAF night fighter operation conducted against Luftwaffe night fighters with a single mosquito joining the landing pattern
MAHWP Missed Approach Holding Waypoint
MAIN GEAR Also Main Landing Gear. The large, heavy-duty landing gear struts and wheels that support most of the weight of the airplane. They are usually under t...
MAINTENANCE Indicates device is in a maintenance mode; Values: non-maintenance, calibration, alignment, bore sight
MALS medium intensity approach light system.
MALSR medium intensity approach light system with runway alignment indicator lights
MAMMUT MAMMOTH. German long range radar with a range of up to 300Km.
MANDREL Airborne radar jamming device operating in the 85-135 MHz waveband to counter the Freya early warning system.
MAP Equipment that produces a map image; See Also: Digital Map Generator
MARKER BEACON (MB) Part of Instrument Landing System that signals crew members of distance to runway, consisting of three markers:. inner, middle, and outer;
MAS Map section of AIP
MAS UAC Maastricht Upper Airspace Center
MASP Minimum Aviation System Performance
MASSAGED Filtered, estimated, or derived, or some combination of the three
MASTER CAUTION A signal which indicates that one or more caution lights has been activated (from MIL-STD-1472D);
MASTER WARNING A signal which indicates that one or more warning lights has been activated (from MIL-STD-1472D);
MATSE ECAC Transport Ministers Meeting on the Air Traffic System in Europe
MATTSCHEIBE FOCUSING SCREEN. German name for the glow in the sky from searchlights, flares and fires against which the bombers were silhouetted.
MATZ Military ATZ
MAUW Maximum All-Up Weight
MAWP Missed Approach Waypoint
MAXIMUM PAYLOAD Maximum Zero Fuel Weight - (minus) Basic Operating Weight
MAYDAY The international radiotelephony distress signal. When repeated three times, it indicates imminent and grave danger and that immediate assistance is r...
MB Marker Beacon
MC Mission computer
MCA Minimum Controllable Airspeed. The speed below which your control surfaces do not generate sufficient lift to control the aircraft.
MCC Millibar (replaced by hPa)
MCI Mobile Communication Infrastructure
MCTR Military CTR
MCU Minimum configuration unit.
MD Medical Doctor
MDA Minimum Descent Altitude
MDAU Maintenance data acquisition unit.
MDF demonstrated flight diving speed.
MDH Major damage history.
ME Multi Engine
MEA Minimum Enroute Altitude
MEAN SEA LEVEL (MSL) The average height of the surface of the sea for all stages of tide; used as a reference for elevations throughout the U.S.
MEASURED Raw data converted to standard units; Compare: derived, estimated, filtered, raw, selected, smoothed
MEL Minimum Equipment List
MEO Medium Earth Orbit
MEP Member of Parliament
MERIDIAN RADIUS OF CURVATURE Radius of the earth in the east/west direction at a given position; Synonyms: earth radius north/south; Symbols: rho sub M; Typical Units: ft; Dimensi...
MET Multi Engine Piston
METAR Meteorological Actual Report (current weather)
MFD Multi Function Display
MH Magnetic Heading
MHP Mental Health Professional (or: psychologist)
MHZ Megahertz (1`000 kHz)
MICROLINE Trade name owned by Collins.
MIDDLE MARKET Marker beacon located where the center of the glide slope is 200ft above the runway
MIDRANGE The power band of an engine between idle and full throttle.
MIL Military
MILES FLOWN The miles (computed in airport-to-airport distances) for each inter-airport hop actually completed in domestic and international revenue services, sch...
MILK RUN Nuisance sorties over Berlin undertaken by Mosquitoes to activate the German air defense system
MILLENNIUM Codename for the first 1000 bomber raid on Cologne 30-31 May 1942.
MISSION COMPUTER (MC) Mission processor;
MISSION OBJECTIVES Goals to be accomplished during a specific mission, including flight plan, NRPs, legs, and a plan on how to accomplish these objectives; plan includes...
MISSION PROCESSOR (MP) A general purpose computer to host avionics software. Synonyms: mission computer;
MIXING Radios with mixing will take two or more controls and mix their output in relation to stick input. The number of channels that can be mixed, and the p...
MIXING ARM A specialized lever which has three or more pivots. The length between pivots will determine the proportion of the mix between two or more linkages.
MIXTURE Fuel to air mixture is determined by the needle valve on the engine carburetor.
MLS Microwave Landing System
MLW Microwave Landing System
MM Middle Marker
MMI Man-Machine Interface (see HMI)
MMO maximum operating limit speed.
MMR Multi-Mode Receiver
MNPS Minimum navigational performance specifications.
MOCA Minimum Obstacle Clearance Altitude
MOD Moderate
MODE Microwave Landing System
MODE-A A transponder which does not give the controllers altitude information
MODE-C A transponder and encoding altimeter which together give air traffic controllers altitude information
MODE-S A transponder which features unique identification per unit, the potential for low-speed up and down data links, and "selective interrogation" trigger...
MODIFIED EVEREST A standard model for computing earth data
MODING CURSOR A symbol on a display, moved by an operator much like arrow keys for menu selection, to select one of several options
MOGAS Motor Gasoline (Auto-Gas)
MOH Major overhaul
MON Motor Octane Number (aviation fuel rating)
MONICA RAF tail fighter-warning device effective up to 4 miles
MOONSHINE Radio jamming device used by RAF to deceive the Freya radars by returning their own signal in an amplified form giving the impression of a larger forc...
MOPS Minimum operational performance standard (RTCA)
MOT Ministry of Transport
MOTOR Any electric motor used in the aircraft. Examples are the servo motors, which move the servo arms, and thus the control surfaces. There are also kits ...
MP Mission processor
MPA Multi-Pilot Airplane
MPH Speed in Miles Per Hour. Like RPM, MPH is both singular and plural. You can go 1 MPH or 100 MPH. You do not go 100 MPH`s.
MRA minimum reception altitude.
MRVA Multi-Pilot Helicopter
MRW Maximum Ramp Weight
MSA Minimum Safe Altitude
MSG Message
MSL Mean sea level
MSP Maintenance Service Program. (Garret engine)
MT Mean Sea Level
MTOM Maximum Take-Off Mass
MTOW Maximum Take-Off Weight
MULTI-MODE RADAR (MMR) A Multi-Mode Radar is used for Terrain Following (TF) and Terrain Avoidance (TA), Ground Mapping (GM) and Air-to Ground Ranging (AGR). The TF mode sup...
MULTIFUNCTION DISPLAY (MFD) The third or fifth tube in an EFIS, it replaces the weather radar screen and displays radar data, navigation maps, checklists and other information.
MVA Minimum Vectoring Altitude
MVAR Magnetic variation
MZFW Maximum Zero-Fuel Weight
N Airspace Euro control project Class N (managed traffic only)
N(....) Country identifier for aircraft registered in USA
N/A not available or not applicable
NAA National Aviation Authority (generic term within JAA)
NABS Navigation Augmentation Broadcast Service (ICAO for GBAS)
NACELLE An enclosure on an aircraft.
NAP-OF-THE-EARTH FLIGHT Flight with a goal to remain close to the earth, usually below the height of surrounding trees and less than 100 ft above the terrain; Compare: terrai...
NARA professional trade association of 54 reputable business companies organized to promote the growth and public understanding of the aircraft resale indu...
NASA National Aeronautics and Space Agency (USA)
NAT North Atlantic Tracks.
NATIONAL AIRSPACE SYSTEM (NAS) The common network of US airspace; air navigation facilities, equipment and services, airports or landing areas; aeronautical charts, information and ...
NATO North Atlantic
NATS National Air Traffic Service (UK)
NATURAL FREQUENCY Standard engineering term See Also: second-order filter; Symbols: omega sub n; Typical Units: rad/s, Hz; Dimensions: 1/Time;
NAUTICAL MILE Measurement of distance. Equals 1.15 statute miles.
NAV Navigation Receivers
NAV/COM Navigation and communication radios combined in a single unit.
NAVAID Navigation Aid (Ground Radio Station for Navigation)
NAVIGABLE AIRSPACE airspace at and above the minimum flight altitudes prescribed by or under this chapter, including airspace needed for safe takeoff and landing
NAVIGATION A system, usually software, in which the primary purpose is to generate position relative to a coordinate frame, usually fixed earth frame, such as la...
NAVIGATION AID A device or process to help with navigation, such as a VOR station or a position update;
NAVIGATION REFERENCE POINT (NRP) A point, usually fixed in earth coordinates but possibly moving; Also, a basic guidance mode, providing lateral guidance to an NRP, either by course o...
NAXOS (FuG 227) German ground radar which produced fixes on H2S.
NAXOS 2 Airborne version of NAXOS.
NBAA IFR FUEL RESERVES Fuel for go-around at destination airport
NDB Navigation
NEAN North European ADS-B Network
NEAR MIDAIR COLLISION (NMAC) An incident associated with the operation of an aircraft in which the possibility of a collision occurs as a result of proximity of less than 500 feet...
NEEDLE VALVE This is used to tune the fuel to air mixture on the engine carburetor. On most engines, the needle is turned clockwise to lean the mixture, and counte...
NELS Northwest Europe Loran Steering Committee
NEPTUN (FuG 216-217-218) German warning device fro attack from the rear or alternatively, a night-fighter search radar.
NICAD (OR NICD) Nickel Cadmium battery. Rechargeable batteries which are typically used as power for radio transmitters and receivers.
NICKELLING Codename for leaflet dropping
NIGHT the time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the American Air Almanac, converted to...
NIL Nothing, no information
NIMBY "Not In My Back-Yard"-Syndrome: "We need an airport but not here"
NITRO Abbreviation for nitro methane. The addition of nitro methane in fuel provides more power, and a smoother idle, thus making the engine easier to tune....
NITRO METHANE The addition of nitro methane in fuel provides more power, and a smoother idle, thus making the engine easier to tune. The nitro also makes an engine ...
NM Nautical Miles. One nautical mile = 1.15 statute miles = 6,080 feet.
NM, NMI Nautical Mile (1.852 km)
NMS Navigation management system.
NMU Navigation management unit.
NOISE Part of received data that is undesired, consisting of random sinusoidal terms added to a signal; Compare: offset, signal;
NON-DIRECTONAL BEACON (NDB) An L/MF or UHF radio beacon transmitting non directional signals whereby the pilot of an aircraft equipped with direction finding equipment can determ...
NON-SCHEDULED SERVICE Revenue flights, such as charter flights, that are not operated in regular scheduled service and all non revenue flights incident to such flights.
NONPRECISION APPROACH PROCEDURE a standard instrument approach procedure in which no electronic glide slope is provided
NOPT no procedure turn required.
NORMALIZER Function to restrict input to a specific range, such as restricting an angle alpha in radians so that -pi le alpha le +pi; angles usually require norm...
NOSAR No Search and Rescue required (Australia)
NOSE The front portion of a aircraft`s fuselage.
NOSE GEAR The strut and wheel that`s under the nose of some aircraft.
NOTAM Notice to Airmen
NOTAR No Tail Rotor
NPA Non-Precision Approach
NPO Non-Profit Organization
NPPL National (ICAO) Private Pilots License (AOPA internally used: IPPL)
NPRM Notice of Proposed Rule-Making (USA)
NRP Navigation reference point
NTSB National Transportation Safety Board. Investigates airplane accidents. Plays at most an advisory role in flightworthiness accreditation.
NVFR Night VFR
NVM Nonvolatile memory. Digital memory that retains information through system shutdown.
NW North-west
O/R on request
OA Obstacle avoidance
OACI Organisation de l`Aviation Civile Internationale (voir ICAO)
OAT Outside Air Temperature
OBERKOMMANDO WEHRMACHT (OKW) German Army General Staff HQ
OBOE RAF target-finding bombing aid using two transmitting stations CAT and MOUSE.
OBS Omni bearing Selector - part of a VOR receiver system, which allows the pilot to select a course to or from a VOR station
OBST Obstacle, obstruction
OBSTACLE AVOIDANCE (OA) Outside Air Temperature
OCD Operational Concept Document
ODIAC Operational Development of Initial Air/ground Data Communications
ODT Operational Requirements and Data Processing Systems Team
OEI one engine inoperative.
OFAC Office F©d©rale de l`Aviation Civile (Swiss CAA - voir BAZL)
OFF Device is powered off (power switch is off; no response to communications) - no data and function is available.
OFFSET Part of received data that is undesired, consisting of a random, time-invariant term added to a signal; Synonyms: bias; Compare: noise, signal
OH Overhaul
OM Outer Marker
OMEGA A very-low-frequency navigation system
OMS Outer Marker Substitute (sort of a virtual OM)
