航空缩略语

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A AAC - Army Air Corps AAIB - Air Accident Investigation Branch of the Department of the Environment, Transport and the Regions. aae - above aerodrome elevation. Also see aal. aal - above aerodrome level. Also see aae. ab initio - elementary flying training, literally 'from the beginning',. abm abeam - an aircraft is abeam a point when that point is at ninety degrees left or right of the aircraft's track, but term usually used to indicate a general position rather than a specific point. a/c - aircraft. ACARS - Aircraft Communication Adressing and Reporting System. AC - alternating current. ACC - Area Control Centre. And ACZ Aerodrome Control Zone. See ATZ below. ACMS - aircraft condition monitoring system. ACR - aerodrome control radar. accelerate-stop distance - calculated distance required for an aircraft to accelerate to V1 (which see), reject take-off and brake safely to a halt. A/D - aerodrome. AD - Airworthiness Directive, issued by airworthiness authorities to correct a defect found in an aircraft type after certification. Compliance is mandatory and may be required immediately and before further flight, within a specified period of time or number of flying hours, or when next due for routine maintenance. ADA - Advisory aispace - Advisory Area or Advisory Route. ADC - air data computer. ADELT - automatically deployable emergency locator transmitter. ADF - automatic direction finder/finding. Radio compass which gives a relative bearing to the non-directional radio beacon to which it is tuned. ADI - attitude deviation indicator. An advanced type of artificial horizon, part of a flight director system providing pitch and roll information and commands. ADIZ - Air Defence Identification Zone. An area of airspace extending upwards from the surface, usually along a national boundary, within which identification of all aircraft is required in the interests of national security. ADR - Accident Data Recorder. ADS - Automatic Dependence Surveillance. ADT - Approved Departure Time. AEF - Aerodromes Environmental Federation. AEW - Airborne early warning Aerad - UK-published flight guide and navigational chart system. aerodrome/airport elevation - highest point of an aerodrome's usable runway(s) expressed in feet above mean sea level (amsl). AFB - air force base, usually U.S. or Canadian. AFCS - automatic flight control system, an advanced autopilot. Also IFCS, integrated flight control system. AFDS - Autopilot and flight director system. AFI - assistant flying instructor. Also AFIC, assistant flying instructor course, FIC, flying instructor course. AFIS - Aerodrome Flight Information Service, providing information to, but not control of, aircraft using that aerodrome. AFIS(O)- Aerodrome Flight Information Service (Officer) AFS - Aerodrome Fire Service. AFS - Aeronautical Fixed Service - telephone/teleprinter network, includes AFTN. AFS - auto flight system. AFTN - Aeronautical Fixed Telecommunications Network. A ground- based teleprinter network transmitting flight plans, weather information etc. AGO - air-to-ground operator A/G - air-to-ground. agl - above ground level. AHRS - attitude-heading reference system. A sensor deriving aircraft attitude and heading information from gyros and accelerometers. AIAA - area of intense aerial activity, usually military. AIC - Aeronautical Information Circular. Bulletins issued at intervals by the CAA relating to matters of airworthiness, administration, operating procedures, safety etc. AICs are colour-coded according to subject, e.g. safety circulars are pink, thus 'Pink 12' issued in December 1990. AIDS - Airborne integrated data system. AIP - Aeronautical Information Publication. The UK Air Pilot, statutory bible of aeronautical information published by the CAA. Airep - form for reporting position and Met conditions in flight. Airmet - CAA's telephone aviation weather service, covering Southern, Northern and Scottish regions of the UK. Also Metdial and Metplan, privately-operated aviation weather services. For full details see Pilot, February 1991. AIS - Aeronautical Information Service. CAA unit based at London-Heathrow Airport, providing flight-planning services and information for pilots. Publishes AICs, above. AIZ - Aerodrome Information Zone. See ATZ below. ALERFA - alert phase of search-and-rescue procedure. alt - altitude. Height above sea level. alternate - aerodrome specified on a flight plan to which an aircraft chooses to divert if a landing at its intended destination is not possible (for reasons of poor weather, for example). altimeter setting - barometric pressure reading in millibars, hectopascals or (in USA) inches of mercury (Hg) used to set a pressure altimeter's sub-scale to QFE or QNH . AM - Amplitude modulation. AME - authorized medical examiner. A doctor approved by the CAA (or foreign licensing authority) to conduct examinations for the issue or renewal of aircrew medical certificates. amsl - above mean sea level (sometimes asl in USA). anhedral - sloping down from root to tip. Opposite: dihedral. ANO - Air Navigation Order. Statutory legal instrument defining the laws of air navigation, pilot licensing etc, in the UK. Other aviation legislation includes the Rules of the Air and Air Traffic regulations and the Air Navigation (General) Regulations AoA - angle of attack. Also alpha, thus 'high alpha', high angle of attack. AOA - Airport Operators' Association. AOC - Air Operator's Certificate, issued by the CAA and required by aircraft operators flying scheduled or charter public transport flights, including cargo, air-taxi and pleasure-flying work. Also Air Officer Commanding in RAF parlance. AoE - airport of entry (usually in USA). AOG - aircraft on ground, a term used to denote urgency when requesting spares or service from suppliers or manufacturers, meaning that the aircraft cannot fly again until the parts have been supplied. AOPA - Aircraft Owners and Pilots Association. A/P - airport or autopilot. A & P - Airframe and Powerplant Mechanic (USA). APA - Aerodromes Protection Agency, the federation of associations for the advancement of British general aviation facilities. APHAZ - Aircraft Proximity Hazards Assessment Panel, which investigates near-miss reports filed by air traffic controllers (see also JAWG). APP - Approach (control). APU - auxiliary power unit. Large transport aircraft and some business jets have an APU, typically a small turbine, to provide power for engine-starting and for running systems when on the ground, obviating the need for external power or ground power unit, GPU. ARB - Airworthiness Review Board. ARCAL - aircraft radio control of aerodrome lighting. Aresti - key shorthand notation system devised by Spaniard José L Aresti whereby aerobatic display routines or competition sequences can be drawn up on paper like a musical score. Now largely superseded by the simpler FAI Aerobatic Catalogue system. ARINC - Aeronautical Radio Incorporated. A non-profit corporation owned by airlines to set standards for airline avionics and provide communications services. ARP - aerodrome reference point. articulated rotor - blades can flap, drag and feather. ARV - air recreational vehicle. ASDA - accelerate-stop distance available. ASI - airspeed indicator, a flight instrument which measures the speed of an aircraft through the air. ASR - altimeter setting region, a geographical area for which the lowest value of QNH is forecast hourly and relayed by air traffic control centres. Also airport surveillance radar and air-sea rescue. ASTOVL - advanced short take-off and vertical landing. ATA - actual time of arrival. Also Air Training Association. ATC - air traffic control. ATCA - air traffic control assistant ATC(C) - air traffic control centre; ATCO - air traffic control officer.. ATIS - automatic terminal information service, a continuous recorded broadcast of routine non-control airport information, usually at large airports. ATPL - Air Transport Pilot's Licence, needed to act as pilot-in- command of a commercial air transport aircraft exceeding 20,000 kg all-up weight. ATO - assisted take-off e.g. J(et) or (R)ocket assisted. ATS - air traffic service. Also ATSU, ATS Unit. ATSORA - air traffic services outside regulated airspace. ATC(U) - air traffic control unit. ATZ - Aerodrome Traffic Zone. An area of protected airspace surrounding an aerodrome bounded by a circle of 2 nm or 2.5 nm radius (depending on runway length) centred on the mid-point of the longest runway. Permission is required for entry into and movement in an ATZ. AUW - all-up weight, a term for the total loaded weight of an aircraft, made up of empty weight plus useful load; maximum auw is the maximum allowable weight, including fuel and payload, specified in an aircraft's Certificate of Airworthiness. Sometimes referred to (in USA especially) as gross weight and maximum gross weight respectively. Also MTWA, maximum total weight authorised; BOW Basic operating weight, the weight of an aircraft with all equipment, lubricants, fuel and operating crew, but without payload; MLW, maximum landing weight, above which fuel must be burned off or jettisoned before landing or there may be risk of structural damage. avgas - aviation gasoline, usually followed by the octane rating. Used by piston-engined aircraft. Also LL, low lead. avtur - aviation turbine fuel (kerosene). Used by turboprops and jets. AWR - airborne weather radar. Awy - airway. B BA - British Airways BAA - British Airports Authority. BAeA - British Aerobatic Association. BALPA - British Airline Pilots Association. base leg - The crosswind segment of an aerodrome circuit bringing the aircraft from the downwind leg to final approach BAUA - Business Aircraft Users Association. BCAR - British Civil Air Requirements. Airworthiness standards laid down by the CAA for certification of aircraft on the UK Civil Aircraft Register. BCP - break cloud procedure. BCPL - Basic Commercial Pilot's Licence, the minimum qualification necessary in the UK to receive payment for acting as a pilot. Also CPL, Commercial Pilot's Licence, and SCPL, Senior Commercial Pilot's Licence (no longer issued). beta mode - manually-controlled mode for CS propellers on turboprop aircraft enabling reverse pitch to be selected for braking or to aid ground manoeuvring. BFR - Biennial Flight Review (USA). Holders of U.S. FAA Private Pilot Licences must undergo a flight check with an FAA-approved examiner every two years. No UK equivalent. BGA - British Gliding Association. BHAB - British Helicopter Advisory Board. bhp - brake horsepower. BHPA - British Hang-Gliding and Paragliding Association. Bleed air - Hot compressed air taken from turbine engines. BMAA - British Microlight Aircraft Association. Bottlang - Loose-leaf Euopean airfields manual for VFR operations. BRG - bearing, the horizontal direction to or from any point expressed in degrees of the compass. BWPA - British Women Pilots Association. C C - Celsius (temperature) or compass. CAA - Civil Aviation Authority. CAD/CAM - computer-aided design/manufacture. CAAFU - Civil Aviation Authority Flying Unit, based at Stansted Airport, which performs such tasks as navaid checking and calibration and also examines candidates for instrument ratings and commercial pilot's licences. CANP - Civil Aviation Notification Procedure. A voluntary system whereby civil operators notify their intention to fly at low level (at or below 1,000 feet agl, when crop-spraying or powerline inspecting for example), aimed at avoiding conflict with low-flying military aircraft. CAP - Civil Air Publication. Information booklets issued by the CAA, e.g. CAP 53 The Private Pilot Licence. CAS - calibrated airspeed -- indicated airspeed corrected for air density and compressibility. casevac - casualty evacuation. CAT - clear-air turbulence. Also CATegory when referring to certain instrument landing systems which require special aircraft instrumentation, certification and pilot qualification beyond those needed for standard instrument approaches (e.g. a CAT IIIC ILS permits operation down to the surface of the runway without external visual reference, true zero-zero operation). CAVOK - pronounced CAV-okay (ceiling and visibility OK), visibility at least ten kilometres, with no cloud below 5,000 feet, with no Cbs, precipitation, thunderstorms, shallow fog or low drifting snow. CAVU - ceiling and visibility unlimited. Cloudless (or scattered cloud) conditions with visibility in excess of ten kilometres. CCF - Combined Cadet Force CDI - course deviation indicator. The vertical needle of a VOR indicator which shows the aircraft's position relative to the selected VOR radial. CDU - control display unit. ceiling - height above ground or water of the base of the lowest layer of cloud below 20,000 feet which covers more than half of the sky. An aircraft's service ceiling is the density altitude at which its maximum rate of climb is no greater than 100 feet per minute. Its absolute ceiling is the highest altitude at which it can maintain level flight. CFI - chief flying instructor (certified flying instructor in USA). CFS - Central Flying School (RAF) CG - centre of gravity CH - compass heading. Check 'A' - a thorough pre-flight inspection - the first of the day. CHIRP - Confidential Human Factors Incident Reporting system, whereby professional pilots and ATC staff may report in confidence incidents arising from human errors for analysis by the CHIRP Charitable Trust at Farnborough. CHT - cylinder head temperature (gauge). A device which, by means of a probe(s) gives a cockpit readout of the temperature of one or more of an aircraft engine's cylinder heads. circuit - pattern around which aircraft fly when arriving at an airfield, usually rectangular in UK but not necessarily elsewhere. The circuit (known as the pattern in USA) is aligned with the active runway and may be either left- or right-handed. Dead side is the opposite side of the circuit pattern in operation from which arriving aircraft join for landing. See also final(s). C/L - centre-line (of a runway, for example). clamped - colloquialism referring to an airport closed to air traffic by bad weather clean - flaps, slats and undercarriage retracted and on military aircraft no external missiles etc. clearance - authorization from air traffic control to proceed as requested or instructed. Used for ground and air manoeuvring, thus "cleared for take-off", "cleared flight-planned route", "cleared to descend" etc. Clouds - commonly-used abbreviations for cloud types: AC = altocumulus AS = altostratus CB = cumulonimbus CC = cirrocumulus CI = cirrus CS = cirrostratus CU = cumulus NS = nimbo stratus SC = stratocumulus ST = stratus C of A - Certificate of Airworthiness issued by the CAA indicating that an aircraft meets the Authority's airworthiness standards. Cs of A are issued to individual aircraft, and also to generic aircraft types (Type Certification in the USA) when the first example of a type is registered. Cs of A on individual aircraft are granted in several categories, e.g. Private, Public Transport, Aerial Work etc. and much be renewed at intervals. Permits to Fly are authorisations granted to specialist aircraft and are accordingly restricted in the kinds of operation for which they may be used. C of E - Certificate of Experience, valid for private pilot licence holders for thirteen months, and renewed by flight test or evidence of completing the minimum required flying experience in the preceding thirteen-month period. Also C of T, certificate of test. C of G - centre of gravity. The point on an aircraft through which the entire aircraft's weight may be assumed to act (i.e. around which the aircraft, if suspended, would balance). C of G limits are the most forward and rearward positions of the C of G permitted for safe operation. An aircraft loaded outside its C of G limits can be difficult or impossible to control. C of P - centre of pressure, the point through which the total effect of lift may be said to act on an aeroplane. Com(m)(s) - communication(s) CPL - Commercial Pilot's Licence CR or C/R - counter-rotating. Usually in general aviation referring to twin-engined aircraft with 'handed' engines whose propellers turn in opposite directions to eliminate propeller torque effect. CRM - cockpit resources management crosswind (leg) - portion of an aerodrome circuit flown before downwind CRP - compulsory reporting point. CRT - cathode ray tube (like a television). Used in flight deck displays of new-generation airliners, business aircraft and military jets instead of conventional instruments. See also EFIS,. critical altitude - the highest density altitude at which it is possible to maintain the maximum continuous rated power or manifold pressure of an aero engine. critical engine - the engine on a multi-engined aircraft whose failure would most seriously effect performance or handling of the aircraft, through asymmetric effects or loss of power to systems such as hydraulics. CRS course - the intended direction of flight in the horizontal plane expressed in degrees of the compass. c/s - call sign. CS - constant-speed (propeller). A variable-pitch propeller which maintains constant rpm by automatically changing blade angle. Also CSU, constant-speed unit. CTA - Control Area. An area of controlled airspace extending upwards from specified limit agl. CTR - Control Zone. An area of controlled airspace extending upwards from ground level to a specified upper limit. CVR - cockpit voice recorder. A tape recorder installed on the flight decks of commercial transport aircraft and helicopters and some business aeroplanes to record crew conversation, RT transmissions and cockpit background noises (e.g. trim-wheel operation, flap motor running) in case required for incident or accident investigation. CW - carrier wave or continuous wave. CWR - colour weather radar. CZ - Control Zone (USA). CZI - compressor zone inspection. D DA - Danger Area. DAAIS - Danger Area Activity Information Service. DACS - Danger Area Crossing Service. DADC - Digital air data computer (DADS - /system). D & D - Distress & Diversion Cells at Air Traffic Control Centres. RAF units which provide a 24-hour listening watch on VHF and UHF emergency frequencies and can locate and assist pilots who are lost or in emergency situations. dB - decibel(s) - a unit of sound DC - direct current DCT - direct dead side - opposite side of an airfield circuit pattern from which aircraft join for landing deadstick - descent and landing with engine(s) shut down and propeller(s) stopped. Decca - hyperbolic area navigation system, originally developed for maritime use, based on signals received from a chain of master and slave ground stations located in northern Europe. DEEC - digital electronic engine control density altitude - pressure altitude corrected for air temperature. derated - engine's potential power deliberately limited, lengthening likely life. DETRESFA - distress phase of search-and-rescue operation. DF - direction-finding. A DF bearing can be provided by airfields or other facilities such as D & D cells (above) having suitable direction-finding equipment to locate an aircraft. DG - Directional gyro DGAC - Direction Général à l'Aviation Civile DH - decision height. The height on a precision approach at which a pilot must have the runway approach lights in sight to continue the descent, or if not, must initiate a go-around. DHFS - UK Defence Helicopter Flying School at RAF Shawbury DI - direction indicator. A gyro instrument which indicates the magnetic heading of an aircraft. The DI, also known as the directional gyro (DG), is free of the turning errors associated with magnetic compasses but is prone to precession (wander) and must be reset against the magnetic compass at intervals. ALSO - DI - is also used to refer to the daily inspection -- a thorough pre-flight check of an aircraft prior to the first flight of the day. dihedral - sloping up from root to tip. Opposite: anhedral. DIN(S) - digital interial navigation (system). DME - distance-measuring equipment. A combination of ground and airborne equipment which gives a continuous slant range distance-from-station readout by measuring time-lapse of a signal transmitted by the aircraft to the station and responded back. DMEs can also provide groundspeed and time-to-station readouts by differentiation. Doppler - Doppler effect (or shift) is the change in frequency of light, radio or sound waves when source and receiver are in relative motion. DoT - Department of Transport. downwind - The segment of an aerodrome circuit paralleling the active runway and flown on a reciprocal heading DP - dew point DR - dead (deduced) reckoning. Plotting position by calculating the effect of speed, course, time and wind against last known position. dry - when referring to aircraft hire charges means 'without fuel', as opposed to wet, with fuel. DZ - dropping zone, for parachuting etc. E EAA - Experimental Aircraft Association, the American homebuilders' organisation. EADI - electronic attitude director indicator. An ADI with CRT cockpit display forming part of an EFIS, below. EAS - equivalent airspeed. EAT - estimated (or expected) approach time. EBAA - European Business Aircraft Association. ECAC - European Civil Aviation Conference. ECOGAS - European Council of General Aviation Support. ECU - environmental control unit. ED - emergency distance. EET - estimated elapsed time. EFAS - electronic flash approach light system. EFATO - engine failure at (or after) take-off. EFIS - electronic flight instrument system, in which multi- function CRT displays replace traditional instruments for providing flight, navigation and aircraft systems information, forming a so-called 'glass cockpit'. Now common in commercial transports, corporate aircraft and helicopters, military fighters and some GA piston singles and twins. EGT - exhaust gas temperature (gauge). A device which provides a cockpit readout of the exhaust gas temperature of an aircraft's (piston) engine(s), enabling the pilot to lean the mixture for maximum fuel efficiency. EHSI - electronic horizontal situation indicator. CRT-based HSI forming part of an EFIS. EICAS - engine indication and crew alerting system. CRT display which monitors engine performance and alerts the crew to system or airframe failure. Found in new-generation transports and business jets. EICMS - engine in-flight monitoring system ELT - emergency locator transmitter. A small radio transmitter fixed to an aircraft's structure which is automatically activated by impact or water immersion and transmits a code on emergency frequencies enabling SAR satellites or search units equipped with DF to locate the crash or ditching site. Carriage mandatory in the USA, but not in UK. Sometimes styled ADELT, automatically deployable ELT, or ELB, emergency locator beacon. empty weight - weight of the basic aeroplane including all fixed equipment, plus unusable fuel, oil, hydraulic and other fluids. encoding altimeter - an altimeter which gives a digital output to the transponder (which see) for automatic transmission of the aircraft's pressure altitude to ATC. EOBT - estimated off-blocks time. EP - Elementary pilot rating of the British Hang Gliding and Paragliding Association EPNdB - effective perceived noise decibel. Unit of measurement of aircraft noise levels. ER - extended range. eshp - equivalent shaft horsepower. ETA - estimated time of arrival. Also ; ETD - estimated time of departure ETE - estimated time en route. ETOPS - extended-range twin operations, usually long over-water flights by airliners. ETPS - Empire Test Pilots School, based at the Aircraft & Armament Experimental Establishment, Boscombe Down. Eurocontrol - organisation, headquartered in The Netherlands, comprising Belgium, France, Germany, Ireland, Luxembourg, Netherlands and UK for coordinating en route air traffic control in Europe.

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F FAA - Federal Aviation Administration, USA, equivalent of UK's CAA. FAA - Fleet Air Arm, of UK's Royal Navy. " D R6 C. ^; s) R 2 F4 V1 O# x6 P `. [( Q$ TFADEC - full-authority digital engine control. . f4 @) n: y) U% ` FAF - final approach fix, the point at which a published instrument approach begins. # P. O1 P; t+ a7 e7 g7 x2 uFAI - Fédération Aéronautique Internationale, the international body for verification of aeronautical record attempts and sporting regulations. ( w: n! |, m q8 A5 V; I# p5 z FAR - Federal Aviation Regulations (USA). . ]- h4 F* a* l- x/ o5 I$ \ FARA - Formula Air Racing Association. $ f; U/ @& h+ s1 k, |0 `% v" qFBL - fly by light i.e. control via optical fibres 1 O# C; H5 @2 |- F' |/ J" \1 ` C 9 R* T8 z, I8 G3 ]! DFBO - 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.) 3 @' T6 s6 D$ f! l( j/ ~; h3 o7 H 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. : ]! D+ l% C9 N; R- `+ N FCS - flight control system. ) p/ O# n5 g3 ^$ n8 L* k0 z9 Dfcst - forecast. % H0 H+ t+ M6 V" _/ B3 X3 VFDR - 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. " r: u) w L3 g/ ~$ J; Bfeather - (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. , y/ Q( v2 h4 u- ~ 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. 8 N. }. _5 l& ^9 S& uFIC - Flight Information Centre. 0 [% Y! e8 h- z; y 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. 1 T; o( u2 y. Z" L+ P! BFJ - fast jet. ( r% Z+ q- [6 M- R: I 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. 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. flameout - combustion failure in a turbine engine resulting in power loss. / w& v, ~& l3 |: q9 }1 R' } / A7 }4 ]5 Y" Q2 p1 oFLG - flashing. ) a3 f/ N5 S7 ]: ]0 V o' y8 ]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. 4 k$ J. u, O% G, _8 W- OFLIR - forward-looking infra-red. FLM - foot-launched microlight. + n# \: g5 G3 Z- MFLPA - foot-launched powered aircraft, e.g. powered parachutes. : a6 x1 S1 S$ Y p( J1 P5 A0 m; M1 KFM - frequency modulation. - F' W3 J7 k* e9 O4 G 0 K* Z! ^( [' j) ]5 YFMC/S - flight management computer/system 4 T7 ]0 t, K2 y l& p; [0 } 6 K) A4 X% Y: h# I; GFMGC - flight management guidance computer. FMS - flight management system. : u( @/ u$ \1 y2 r/ r7 S FMU - flight management unit. ; i' N- m+ k9 [/ HFOD - foreign object damage, usually to turbine engines through ingestion of runway debris etc. 4 B6 u1 O, T7 v K FPL - filed flight plan. ) B. B% [" W1 j9 ~+ p( e. Y+ O$ Sfpm - feet per minute, a measure of an aircraft's rate of climb or descent. Similarly m/s or mps, metres per second. 8 h6 |! f2 |9 f- j; U! l( q FSS - Flight Service Station (USA). ) Y+ f/ u( A' u3 o! u + `0 r Y; y' R# @6 f+ a9 yFTO - flying training organisation. ) u2 i) n( d& V) c t3 l$ w# F% ^ FTS - Flying Training School (RAF) 4 s$ e: w# p' ]+ `1 ^& X& K ft/min - feet per minute % Q$ m7 e+ h H4 d" B9 M F( }. y 4 T$ X2 o) a& O7 n/ ~G + X% y' @; o& |5 R5 Hg - the acceleration force of gravity, normally 1g on earth. Zero g (0g) is weightlessness, as experienced by orbiting astronauts. g is expressed as positive (+) and negative (-) values. During a normal loop a pilot experiences positive g, tending to force him down in his seat. In an outside loop, with the pilot's head on the outside of the vertical circle, negative g forces him up against his straps. Aircraft structural load limits are expressed in positive and negative values, the positive limit usually greater than negative, except in specialist aerobatic types. / X$ A3 K2 W% r# m+ x ( ?( a% w. K/ C9 }# c' j8 yg-loc - g-induced loss of consciousness. Pilot blackouts caused by excessive g or by too-rapid onset of g-forces. Experienced mostly by pilots of high-performance military jets and competition aerobatic aircraft, has led to fatal crashes. & ~7 d+ C1 U! S% ^/ M " | V! C3 L* t$ n2 a4 QGA - general aviation, all flying other than airlines and the military. , i8 u0 H/ P# }* o b GAAC - General Aviation Awareness Campaign. / x- Z. T8 B5 r8 t! d1 `2 [ GAFOR - General Aviation Visual Flight Forecast. Met briefing service in operation in France, Germany, the Netherlands and some other European countries. gall imp/U.S. - gallons, imperial or USA. One imp gall = 1.201 U.S. gall. GAMA - General Aviation Manufacturers Association, an American trade organisation. 3 C) x. k- X, e- m4 aGAMTA - General Aviation Manufacturers & Traders Association, UK. GAPAN - Guild of Air Pilots and Air Navigators. + D" Z; ^ X; n Z4 uGASCo - General Aviation Safety Council T% n* A& {! ]/ I7 s$ P 1 |/ b& `4 W* Q5 D. xGASIL - General Aviation Safety Information Leaflet. Monthly safety and accident prevention bulletin for pilots and engineers published by the CAA. 2 s, x4 E' S0 y' k: k; u2 R1 OGCA - ground-controlled approach. A landing approach in which a ground controller gives verbal guidance in azimuth and elevation to a pilot using precision approach radar (PAR) to monitor the aircraft's approach path. Still used by the military, but defunct in civil aviation. 8 a+ L" o& `* d' C, H( k, N! f' L" iGFT - General Flying Test, taken by student pilots to qualify for the PPL, and also by candidates for the BCPL and CPL. Also NFT, navigation flight test, which is part of the practical examination for the PPL. % G* e' ?1 M1 O+ A0 G' v/ F" T+ F: { Glonass - Russian equivalent of GPS/Navstar satellite navigation system. glove - non-movable part of a variable geometry wing. 5 t2 Y7 n" |( W. z ( w8 Q6 @7 _! D4 F8 P5 j$ t2 ^gnd - ground 6 W0 L9 n p4 i L/ C" a& V 6 j- U: ?' Y3 q/ ]& I) r1 bGNSS - Global Navigation Satellite Systems. 2 I: D k. E0 p4 A. ~ k go-around to climb away from a runway after making an approach, either to make a further attempt at landing or to divert to an alternate airport (formerly 'overshoot'). Goxio - VHF direction-finding (France) / R' S+ T$ f" a2 k* q, k ( d2 z8 n$ r/ Q9 e6 I, ~GP - glidepath 2 X& A! j) [* [. z. z3 L: l5 U& V gph - gallons per hour, an expression of fuel consumption or fuel flow (FF) in either imperial or U.S. gallons. Usually lb/hr for turbine-powered aircraft. , l$ C8 N6 \, b GPS - Global Positioning System (Navstar). A U.S. developed satellite-based high-precision navigation system, intended primarily for military use but now in widespread use by commercial and private operators, though with reduced accuracy compared with military versions. / ?' I: }6 `* Q) d1 c, t: o& x1 o! o & M6 r8 s6 l! b# s6 dGPWS - ground proximity warning system. A radar-based flight- deck system to give pilots audible warning by means of horns, hooters, taped or synthetic voices of terrain close beneath an aircraft's flight path. GRADU - gradual (term used in Met reports). 3 G: W# P' C7 D4 L ; G& k# [, {$ X7 MGRP - glassfibre-reinforced plastic; also CFRP, carbon-fibre reinforced plastic. Composite materials seeing increasing use in entire airframes for GA aircraft (e.g. Beech Starship) and for components for helicopters, airliners and military aircraft. ) K$ _$ q7 @5 _* \GS - glideslope. The vertical guidance part of an instrument landing system which establishes a safe glidepath (usually three degrees) to a runway. / T; ~9 y" G# p. ~$ x4 r9 ?& @ ( ?, Z) C% z! f7 OG/S - groundspeed. The speed an aircraft makes over the ground, a product of its airspeed and wind speed. ; Q. i h5 i" H0 S# Q8 G A, M / z" d" F0 X+ W7 n7 |H H24 - continuous round-the-clock operation. Also HJ operates during day; HN operates during night; HO operates during times to meet operational requirements, and HX no specific operational hours. 3 D* h2 B; @ t HAA - Historic Aircraft Association. " z; _: J' c" k" u2 T# a HAI - Helicopter Association International. half-mill(ion) - 1:500,000 scale ICAO aeronautical chart. : h( K1 u; P/ a W Hdg - heading. The direction in which an aircraft's nose points in flight in the horizontal plane, expressed in compass degrees. 8 n) ?6 e% @8 |0 {! S. z : @' y+ `( u" e" \Heavy - suffix used in RT callsigns to indicate that the aircraft is a large transport, alerting controllers and following aircraft to the possibility of wake turbulence . , v$ M+ h# b7 }; r5 `) mHectopascal (hPa) - unit of pressure measurement, equivalent to one millibar (which see), now the ICAO-standard for altimeter setting. ! V6 G- J8 j `! [+ M/ b/ t5 EHEMS - helicopter emergency medical services. a& S2 H9 B+ ^ Hertz - standard radio equivalent of frequency in cycles per second. See also kHz and MHz. i7 U, f$ o3 F4 A2 B& u 9 T/ [" [' D5 Q& T ?( s8 ?9 NHF - high-frequency band, used for long-range radio communications in the 3-30 MHz range. Hg - inches of mercury, a unit of pressure measurement. % u! y7 F! x8 C/ a HIAL - high intensity approach lighting. + Z9 C8 Z6 d7 G0 N* H+ C. m# I$ ]HIGE - hover in ground effect. Also see HOGE. 7 M8 g4 J. H. k4 cHIRF - high intensity radiated (electromagnetic) fields. " N/ u& G8 v2 s4 x" E. ^HIRL - high intensity runway lighting. HISL - high intensity strobe light. % k T! g) l6 |8 f) J) `& h3 mholding pattern - racetrack-shaped manoeuvre which keeps aircraft within a specified airspace while awaiting further clearance from air traffic control. % T7 D y6 _/ j6 k+ p! s( `6 MHOCAC - hands on cyclic and collective - see HOTAS below. 8 c* p5 @/ Y. ^0 A, x/ {8 d HOGE - hover out of ground effect. Also see HIGE. & F- x5 t; ~- ^- Y) V+ U hot-and-high - airfield conditions of high altitude and high ambient temperatures that can severely limit aircraft performance. See also density altitude. HOTAS - hands on throttle and stick. Ergonomic cockpit design technology, originally developed for military combat aircraft, enabling a pilot to fly the aircraft and manage all navigation, weapons and other systems from control column/throttle lever hand grips. ! H( Y: {! K/ P; RHOTCC - hands on throttle, collective & cyclic - see HOTAS above. " z: q- a* a& a& D hp - horsepower. HRA - Highlands Restricted Area hrs - hours 5 |5 U9 X5 s: ?9 V+ C- v7 m. e - d; f2 j7 a# ^8 M" _( mHSD - horizontal situation display. 7 }# C4 S& @- W0 r HSI - horizontal situation indicator. A cockpit navigation display, usually part of a flight-director system, which combines navigation and heading. HUD - head-up display. A method of projecting instrument readouts or data which enables a pilot to see them while looking through the aircraft's windscreen. Mostly used on military aircraft, but now in service on some commercial airliners. $ I3 t$ T0 i) k# \$ V+ f: P " h/ g1 \4 [8 G; F) g& DHz - Hertz. I IAOPA - International Council of Aircraft Owners and Pilots Associations 5 g5 S) a; j2 j9 {5 L0 ^IAS - indicated airspeed. An aircraft's speed through the air as indicated by the ASI, without correction for position error, altitude or outside air temperature. Also see CAS, RAS and TAS. ) v0 B6 |+ p2 R. [, N( _+ pIATA - International Air Transport Association. 3 B3 i0 n( D& Q i/c - intercom : f$ Y( ?7 X5 T( o7 y/ d8 LICAO - International Civil Aviation Organisation. 7 [ h6 [+ L# k& ` : s6 f% c6 c, N1 n7 ZIF - instrument flying. Also intermediate frequency. ' t( s" B7 K1 }2 X" @7 s4 GIFF - identification friend or foe. IFR - instrument flight rules prescribed for the operation of aircraft in instrument meteorological conditions (see below). Flight in most controlled airspace in the UK is conducted under IFR or Special VFR. Also used by military to denote in-flight refuelling. 6 b S% Y5 ^: c/ q3 MIGE - in ground effect. Helicopter performance with an earth surface immediately below. Also OGE, out of ground effect. Helicopters can hover at a greater maximum altitude IGE (above a mountain slope, for example) than they can in free air, OGE. IGS - instrument guidance system. : l" L+ C+ X! FILS - instrument landing system. The approach aid employing two radio beams to provide pilots with vertical and horizontal guidance during the landing approach. The localiser provides azimuth guidance, while the glide-slope defines the correct vertical descent profile. Marker beacons and high intensity runways lights are also part of the ILS. 8 T$ h9 Z4 g/ H IMC - instrument meteorological conditions: weather below VMC minima, see below. Also associated rating used in conjunction with UK PPL. INCERFA - uncertainty phase of search-and-rescue procedure. & k; w: j( B% o INS - inertial navigation system. A gyroscope-based system which senses acceleration and deceleration and computes an aircraft's position in latitude and longitude with great accuracy. Used mostly by long-haul airliners, military aircraft and sophisticated business jets. Also IRS, inertial reference system. 1 z9 `+ r% {4 l4 ?' J& w: a6 m% iINTER - intermittent or fluctuating, term used in Met reports. # T* W9 Q, I. I& U, O$ L% G $ G; {( C7 v! ]* N- O" zIR - Instrument Rating ; q: R" C# D" ?7 I F IRAN - Inspect and repair as necessary ' f( Q/ H2 A, i1 q IRE - Instrument Rating Examiner IRT - Instrument Rating Test 7 [5 \' e L% V8 g# [ ISA - International Standard Atmosphere -- a set of standard conditions or temperature and pressure which serve as a basis for comparison. ISA = pressure 1013.2 millibars, temperature 15 degrees C. Aircraft performance figures quoted by manufacturers are often based on such a 'standard day'. $ z8 W/ E+ ~. i ITT - inter-turbine temperature. Also TGT, turbine gas temperature TIT, turbine inlet temperature. & Z2 f$ N$ F4 b. a h 1 r9 q4 e8 a. E+ H8 d1 Y. u$ d, ZIWR - Instrument weather rating. Proposed by the JAA as a replacement for the UK's unique IMC rating a" {% C8 G) Y/ {0 p+ { / j. q6 w0 q5 f9 R3 [J ' z' o1 m+ e( KJAA - Joint Aviation Authority. 8 s+ r, w2 Q% t2 T 1 p6 U' Z' J" ]! Z; s# ~1 `JAR - Joint Aviation Requirements, being drawn up by eighteen European states, aimed at unifying airworthiness, flight crew licensing and other criteria among signatory nations. 6 K+ `5 m; h. I! g3 V0 Y4 Q # a/ i: U" h9 u: v0 {JAWG - Joint Airmiss Working Group. A civilian/military committee which reviews and reports on all airmisses which occur in UK airspace. : U' v) p! ?/ ]4 RJEFTS - Joint Elementary Flying Training Squadron based at RAF Barkston Heath, Lincolnshire ; Y. Q) X& H( b' z" j* c! vJeppesen - U.S.-developed navigational/approach chart system with worldwide coverage, similar to British Aerad system. JPATS - Joint Primary Aircraft Training System. A USAF/U.S. Navy programme to select a common aircraft design as a basic pilot trainer for the two services, due to be decided next year. 6 M, z& q1 E; A- s8 F" TK kg - kilogram(s) * d4 h) p6 ~+ P; ? Y! k # l2 l4 Z: \% ]" O$ ?5 a' dkHz - kilohertz, the frequency of a radio carrier wave measured in thousands of cycles per second. 1 kHz = 1,000 Hertz. ; A8 V$ ~6 W1 XKIAS - knots indicated airspeed. + B$ d) ~, J& V' m/ P9 F6 a3 U km - kilomrtre(s) knot (kt) - one nautical mile per hour (never one knot per hour), the standard unit of aviation speed measurement. One knot equals 1.1515 mph; one nautical mile equals 6,080 feet. * q- w# k4 h. [; T- m kV- kilovolt 2 v) R- C4 C& T ! h$ o" \' i% Q# P( k; ]kW - kilowatt. / i9 e/ t$ L2 u $ _1 R4 u" O9 @) RL LARS - Lower Airspace Radar Advisory service, available to all aircraft flying in uncontrolled UK airspace from 3,000 feet amsl to FL95. See also MMARS, RAS and RIS, below. 4 f7 ?! K& X3 uLAMS - Light Aircraft Maintenance Schedule, the CAA-approved schedule for fixed-wing light aircraft below 2,730 kg auw whose Cs of A are valid for three years subject to compliance with LAMS. % @3 X) s) f K: n- l/ J# E lat - latitude. ( S# ~% Y. O: |2 g# G1 ~% G$ z/ ALATCC - London Area & Terminal Control Centre at West Drayton, near Heathrow. 1 g2 I5 C- I' nlb - pound(s) lbf - engine thrust in pounds force / C" u% N# |3 ELCD - liquid crystal display 8 N* T/ ^+ l& I" {& t 5 G5 s% P& p; j4 R, q% r9 v5 klczt - (ILS) localizer (USA) , R/ p6 Q8 e/ w2 J( M% z( tl/d ratio - lift /drag ratio, a measurement of the efficiency of a wing aerofoil section LDA - landing distance available. 0 P/ I! n- {; g8 N' d; ?/ x" I LED - light emitting diode 9 e$ b, A/ Q) d LF - low-frequency radio waves with frequencies in the 30-300 kHz band. # K1 Q( x; z# N9 [LITAS - low-intensity two-colour approach system. 3 i' k0 R1 w z, g' i . q3 S' T0 i/ q/ m- N, b& sLLTV - low light level television. * |: ^/ f' z( j! Z. g0 gLLZ - localizer ((USA). # C, M) X2 [$ U$ v / x @8 G4 D) M7 Z8 dLOC - localiser. The azimuth guidance portion of an instrument landing system. locator - medium-frequency non-directional radio beacon used as an aid to establishing yourself on final approach during an instrument landing procedure.. LOFT - Line-orientated flying training. Usually on large jet simulators to prepare newly-qualified commercial pilots for multi-crew airline operations - f9 p# m9 \/ E; Q LOM - Locator outer marker lon(g) - longitude : g" v, x; U+ f8 K, T8 t LLoran - low-frequency hyperbolic radio long-range navigation system which measures time difference between reception of synchronised signals transmitted from ground transmitters. Loran-C, operates in the 100-110 kHz frequency band with an operating range of 600-1,500 nm independent of line-of-sight, and is becoming very popular among GA aircraft operators in the USA.

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M M or mag - magnetic * w. p1 V. _1 I1 l ' r' |& e3 m6 c8 W. e' K! UMach number - ratio of true airspeed to the speed of sound. Mach 1 is the speed of sound at sea level, ISA, approximately 1,100 feet per second or 760 mph. 0 i# L6 w& L- V+ _ $ ]2 Y" G. u: I, g) a. m1 uMAP - missed approach point. The point on a published ILS approach expressed in time or distance from the final approach fix, or as an altitude on the glideslope, at which the missed approach procedure must be initiated if the runway or approach lights are not clearly in sight. " c9 [) o0 r$ |$ Z- S- Gmarker beacons (mkrs) - part of an instrument landing system using 75 MHz transmitters emitting fan-shaped or elliptical signal patterns vertically upwards, defining specific points along the glideslope. The outer marker OM is situated at or near the glideslope intercept altitude of the ILS localiser, the middle marker (MM) defines a point on the glideslope at or near decision height (DH). Markers provide aural and visual indications on a cockpit marker beacon receiver. 7 u$ b7 J. a4 B : x0 E7 r2 G, ~' B1 d. j2 i2 {MATZ - military aerodrome traffic zone. An area of protected airspace surrounding certain military airfields which normally extends for a five nautical mile radius around the airfield and upwards from the surface to 3,000 feet above aerodrome level. A 'stub' projection protects the final approach path to the main runway outwards from the MATZ boundary, enclosing an area two nautical miles either side of the extended runway centreline and upwards from 1,000 feet above the surface to 3,000 feet above aerodrome elevation. Although recognition of a MATZ is not mandatory for civil aircraft, all MATZ aerodromes offer a penetration service to civil traffic during operational hours. ; Z6 `. ]4 q8 m7 R6 T. b8 y4 { Mayday - international radio distress call (from the French, m'aidez -- help me). It signifies imminent danger to life requiring immediate assistance. 6 p/ T' e! c9 o1 m% Y q7 g) D& @ mb - millibar. ' S2 O( `4 a7 f% `* K2 ~ o! n2 v v ]% [( X8 g5 ]2 I0 SMCC - Multi-crew co-operation MCU - management control unit ! C) |, m& D) ]8 _MDA - minimum descent altitude. The lowest altitude, in feet amsl, to which descent is authorised on final approach during a non-precision instrument landing (i.e. where no glideslope guidance is given) without visual reference to the runway. * A {9 d& [: P( P5 sMDH - minimum descent height, agl. MEDA - military emergency diversion airfield. : P* y3 u; n' e1 w+ R medevac - medical evacuation Met - meteorology, weather. 8 u R- `+ r) p! OMETAR - coded aerodrome Met report. Also SPECI, special civil aviation weather report, and TAF, terminal aerodrome forecast of weather expected. 9 H/ i/ T: Y5 X6 h" a ) I/ _ W; T' f# | A$ d% TMF - medium frequency. Radio waves with frequencies in the 300- 3,000 kHz range. ( d. Y; g( `* X- J. ZMFA - military flying area ; k2 R. d. c- tMFD - multi-function display. An EFIS CRT offering selectable displays of weather radar, navigation maps, checklists and data other than primary flight information. / \" `+ r3 A, h, W' J % y$ h/ t3 t/ p. n$ o8 c; NMH - magnetic heading ; ?9 u' Z) r J% v6 v7 w$ { 8 ~$ T2 Y! X. vMHz - Megahertz, the frequency of radio carrier waves measured in millions of cycles per second. 2 S; C% y! Y! f% c7 O: W . @6 O9 l' e$ H3 O/ M. C! }/ aminimums - weather condition requirements for a particular mode of flight (e.g. for VFR operation, IFR take-offs and landings). MLS - microwave landing system. A microwave-based instrument approach system intended to replace ILS in the 1990s and claimed to offer a number of advantages such as the ability to fly segmented and curved precision approaches. 2 W& k! | l4 E2 U" f MLW - maximum landing weight. Weight of an aircraft above whivh fuel must be burned off or jettisoned before landing or there may be risk of structual damage % ]; }0 w" K' U& h mm - millimetre's & a, Y) L! k+ x: j) Q6 |' V/ E MMARS - Military Middle Airspace Radar Service, available to military and civil aircraft operating in UK airspace between FL100 and FL245. & h# D' r$ t* L7 G" I1 r6 QMOA - military operations area. , I. z I0 d5 N8 r5 { q7 { MoD - UK's Ministry of Defence mod - modification to an aircraft or equipment mogas - car fuel, approved for use in some light aircraft subject to certain conditions. MPA - man-powered aircraft + C3 T1 Y! a" N9 a9 R; z6 G; O. K mph - miles per hour # m; P6 K/ W* M' @# ^8 N$ [- H: | MPI - major periodic inspection 7 d4 W6 G: B2 l I [' S MSA - minimum sector altitude or minimum safe altitude. & }) P' N Z: U3 z 9 f% Y. I. c* c$ n) Pmsl - mean sea level 8 w7 p5 l8 M& P' l8 d7 L : z/ F' Q4 t: p$ [+ E2 \MTBF - mean time between failures. Also MTTR, mean time to repair / _1 Y6 e5 I# B% }1 SMTMA - military terminal control area. 3 W# @1 d* \+ E0 J6 p i+ q " ]/ x% x W) t7 }MTOW - maximum take-off weight. The maximum allowable weight, including fuel and payload, specified in an aircraft's Certificate of Airworthiness , sometime referred to (in USA especially) as maximum gross weight. 1 j$ i) t4 O: M# C2 M% z. k ~/ Y ' Q/ P E: i; K0 V9 YMTWA - maximum total weight authorised. " ` O- g# O$ C. I# P 2 w) B- _, V5 Z, C2 E& x. GN % C# i& N8 Y" m2 ] 8 B) a; Y# g" b( m8 c9 t. SNAS - Naval Air Station (USA) NATS - National Air Traffic Services. A division of the CAA providing UK air traffic control. . t! a* |7 c) ~7 y8 f Nav - navigation. 3 n, T0 B3 M" k. j: b. c / j, J# b9 c5 @, O5 uNavaid - navigation aid. " }/ X2 m/ v& l Nav/Com - navigation and communication. - E! ~' \( c9 eNBAA - National Business Aircraft Association, USA. 6 h' a: Z- D0 R9 V: \; XNDB - non-directional beacon. A medium-frequency navigational aid which transmits non-directional signals, superimposed with a Morse code identifier and received by an aircraft's ADF. 1 x/ Q0 w/ U4 ^. \& vNFT - navigation flight test , {3 Z% Q) \5 ?1 ^ ; ]% S+ V1 a9 w3 jnm - nautical mile(s). ; e' `- A8 b- [3 P% QNOE - nap of earth. Low flying, usually by the military, using contour-flying techniques and terrain-masking to avoid being seen. & a- E, F+ R3 O" f * i, p3 j- }7 ~( B9 M% NNORDO - no radio (used on flight plan form). 0 S2 f/ A3 p9 n* D8 S + U. _6 F$ J/ t* M u5 f& |NOSIG - no significant change, term used on Met reports. 1 n( x/ K+ `: j' U) {4 I' J; C NOTAM - Notices to Airmen, issued by the CAA (and equivalent authorities elsewhere) to inform pilots of new or changed aeronautical facilities, services, procedures or hazards, temporary or permanent. Also SNOWTAM NOTAR - no tail rotor. A system patented by McDonnell Douglas for maintaining directional control of helicopters without use of an anti-torque tail rotor. # n5 G3 K+ r! n2 r NPRM - Notice of Proposed Rule-Making (USA). Advance publication by the FAA of proposed changes or additions to Federal Air Regulations. , k6 A T+ k8 \% C6 y) fNTSB - National Transportation Safety Board. U.S. equivalent of UK's AAIB. : C% R/ p/ R" }$ Q+ }nvg - night vision goggles. 7 J3 }5 p7 a) f5 s% w" e( Z2 i + `0 e8 i9 G' j* c- |NVQ - National Vocational Qualification. A Government-recognised qualification, the cost of training for which can be set against tax. # w) n! I8 g M0 v# K+ K 8 s3 Y% ^$ z" {! ~% W7 @0 `9 vO OASC - Officers and Aircrew Selection Centre at RAF Cranwell 1 {& T; U" [' E OAT - outside air temperature. The temperature of the air outside an aircraft measured by a probe with a cockpit gauge readout. OAT affects the measurement of indicated airspeed and its value is needed to calculate true airspeed. At high speeds kinetic heating demands correction to the indicated OAT for true outside air temperature. 4 g' A$ g+ b: _+ |, z4 Q 8 R' ] e' K6 ?5 l' U; |9 d) c9 _OATS - Oxford Air Training School, a large commercial pilot training school at Oxford Airport, UK. ) E. l- q" V( Z7 {) f& C: z% T obst - obstruction. OBS - omni-bearing selector, part of a VOR used to select the radial from a VOR. & B7 o( \2 M/ c* U9 R) H& k, \% o % N# s" v6 O* N G1 ~OCH - obstacle clearance height. The lowest height above the elevation of the runway threshold or above aerodrome elevation used to establish compliance with obstacle clearance criteria in an instrument approach. Also OCA, obstacle clearance altitude, and OCL, obstacle clearance limit. OCU - Operational Conversion Unit. & T* m( {9 Z& jOEI - One engine inoperative OEM - original equipment manufacturer. 6 j4 R( U1 Z7 j3 h+ i# l; {OGE - Out of ground effect ) q# c" P( n/ Aokta - a measurement of cloud cover. One okta means one-eighth of the sky is covered. + n7 y; j% H( l7 r0 {5 U# t9 G1 o Omega - high accuracy, very-low frequency (VLF) long-range navigation system of the hyperbolic type, covering the entire earth down to the surface from eight ground-based transmitters. Used principally by airliners, military aircraft and intercontinental business aircraft. 4 N1 |/ u! y% e3 G R& ?! |7 p ops - Operations 3 @8 x( V! ~3 _, u( Zo/r - on request. 2 m4 F6 u4 D8 |, x o/t - other times. ' q1 S. }5 |: x: [2 N / f- ^' M: h8 s, s: S' gOTU - Operational Training Unit. P % G9 m5 r- a. i1 C* X. z" Z) w8 J0 p2 c P1 - Pilot-n-command P2 - co-pilot Pan - international radio call signalling urgency. PAPI - precision approach path indicator, a system of coloured lights installed at the approach end of a runway which provides visual guidance to the correct glidepath. A successor to VASI, below. , j5 B6 x) x1 p. ?) } PAR - precision approach radar. Primary radar equipment showing an air traffic controller the height, track and range of an aircraft on final approach, enabling him to guide it to a landing. ) _' ]) M$ H* W0 apax - passengers. PED - portable electronic devices. Permit to Fly - Authorisation granted to aircraft such as homebuilds, vintage aeroplanes, warbirds and some simple 'classic' light aircraft which are not required to meet the standards demanded for a full C of A, and are accordingly restricted in the kinds of operation for which they may be used. 9 R3 Z7 Q% P* q) f2 J! c/ j ! {4 m# [0 `8 Y- j; s- j/ APF - Pilot flying. The 'handling pilot' in multi-crew operation. k6 `+ g" J' x4 t$ K PFA - Popular Flying Association, the UK homebuilt and antique aircraft organisation. * ]: S5 A7 g: ]4 q/ f# y5 |PFD - primary flight display 7 a+ t* \5 Y e: x& G6 L 4 p+ a x: X, jPHG - powered hang-glider ; |" V0 R, K. b) G# T0 n( S% O PIC - pilot-in-command (also styled P1). PIG - Pilots Information Guide * d6 g+ a; c+ `7 ~* v7 } 4 X; y1 o8 D; I, Zpinch-hitter - U.S. term for safety-pilot, usually unlicensed but having sufficient training to be competent to land an aircraft in an emergency. Frequently the partner of the PIC $ J y8 M# R+ H( O PINS - Pipeline Inspection Notification System. 7 ]3 \2 S+ s7 g8 o5 F" c * T' F0 M1 ~7 c4 UPIO - pilot-induced oscillation. An undulating flight path brought about by over-controlling. PLN - flight-plan. PMS - performance management system. " a: h! k' U% C" LPNF - Pilot not flying. The 'non-handling' pilot in multi-crew operation PNR - point of no return. ; t2 X3 k! Z1 D5 J3 o' `: Q( o7 W6 }POB - (number of) persons on board. Also SOB, souls on board. POC - proof-of-concept. ' P$ z( h+ J x3 E# U. D3 Q$ KPOH - pilot's operating handbook, an aircraft's 'owner's manual'. 2 a/ G! s8 P. p& oPooley's - annually-published flight guide to United Kingdom and Ireland, named after its creator and publisher Bob Pooley. ) M) O7 i2 q3 \9 k / g* t- |! g, hPPG - powered paraglider. : v! A7 x, m% W8 P7 [( ? PPL - Private Pilot's Licence. ! H7 v/ B- ~9 P6 a PPL(H) - Private Pilot's Licence for helicopters, 6 X/ g+ R, c+ {* B( I) xPPL(SLMG) - Private Pilot's Licence for self-launched motor gliders. 3 K' F' V$ w. S- \6 m# |5 } 4 u0 j& K3 q% t* m0 i G. pPPO - prior permission only. Certain airfields or events require advance notification (by telephone, for example) of your intended arrival. l: C6 [1 [/ ?3 \% H3 b PROB - probability percentage, term used in Met reports. & S4 n( u) ^& T; A% ` 1 x7 T& f6 X; t% X1 r1 H+ Fprocedure turn - manoeuvre which reverses the direction of an aircraft's flight during an instrument approach procedure to enable it to intercept the final approach course. % G: q/ F; l$ DPPR - prior permission required ) a8 I' Y: u1 z/ |/ A2 t psi - pounds per square inch, a measurement of pressure. 8 ~ p* ]8 P$ R7 X: f) pPTT - press-to-transmit (switch) on an aircraft's control wheel or stick enabling the pilot to make RT transmission 'hands on' via a headset microphone. Purple Airspace - special temporary airways created for flights by certain members of the royal family, notified by NOTAM. ) ^: N. h; j: i3 o4 s3 l5 s Q ' [. | t6 @; M$ uQFI - Qualified Flying Instructor. QHI - Qualified helicopter instructor. $ M" u/ T; @* q% ~! v eQuadrantal Rule - system of cruising altitudes used in UK uncontrolled airspace below FL250. Quarter-million - 1:250,000 scale ICAO aeronautical chart Q-code - code system developed when air-to-ground communication was by wireless telegraphy, enabling many routine phrases and questions to be reduced to three letters. Now largely redundant, except these: QDM magnetic bearing to a direction-finding station. 2 ^( O2 c7 I0 SQDR magnetic bearing from the station. QFE atmospheric pressure at aerodrome elevation. With its sub-scale set to the aerodrome QFE an altimeter will indicate height above that airfield. ) _/ m7 D" P* `+ D$ y fQFU magnetic orientation of runway in use. ) y! d* N c% X- J! FQNE reading in feet on an altimeter set to 1013.2 millibars (standard pressure) when the aircraft is at aerodrome elevation. QNH altitude above mean sea level based on local station pressure. QSI change of frequency (use of QSY is officially discouraged in the UK but it is still in use in some other countries) " G3 R& g" W& G% a9 EQTE true line of position from a direction-finding station. 0 G0 O: U" F5 d- W% ~9 G, k. @$ @* ~QUJ true bearing R RAC - Rules of the Air and Air Traffic Services section of the AIP - T" F% Y; r2 N3 H& d) `rabbit lights - colloquialism for sequentially flashing lead-in runway approach lights. RAeS - Royal Aeronautical Society 8 i" b' T0 h( a3 TRAF - Royal Air Force ; h& o# e" Y4 z/ e1 M8 M ramp weight - maximum permissible weight of an aircraft, which exceeds maximum take-off weight by an allowance for fuel burned during engine-start and taxi. 0 V4 e A( d8 a& A+ yRAPID - change expected to take place in thirty minutes or less, term used in mer reports. : x3 ]6 ?7 n' a* q& ~- Q- Z; J RAS (1) - rectified airspeed. Indicated airspeed corrected for instrument position error. ! a& y, g* S4 C j% Z* ~6 ARAS (2) - Radar Advisory Service. Provided outside regulated airspace to notify pilots of conflicting traffic and to advise suitable avoiding action. Under RAS controllers aim to achieve a minimum separation of five miles or 5,000 feet against unknown conflicting traffic " V( ^& J0 G# O8 Y Rating - add-on qualification to a pilot's licence, e.g. Night Rating, Multi-engine Rating, Instrument Rating, Seaplane Rating etc. Individual Type Ratings are necessary to fly aircraft over 12,500 pounds MTWA. RCL - runway centre-line. - [6 Q0 C. G( m O3 D : k+ A+ {: Q9 ?$ g, ]% |$ U% ]RBI - relative bearing indicator, displaying information from the ADF. ( v5 u% ~ x% b3 K+ _ ) l% N& R7 R k6 ORDO - radio. RIS - Radar Information Service. Provided to notify pilots of conflicting traffic outside regulated airspace, but offering no avoiding action. ! d- i- e' v+ L/ f9 S: k , K# _9 k* d5 \1 \6 Z. ~RMI - radio magnetic indicator. A navigation aid which combines DI, VOR and/or ADF display and will indicate bearings to stations, together with aircraft heading. RMK - remark(s). ' E7 \6 J" ? S0 Y / ~& e0 y, ~( w+ w% o. MRMU - radio management unit. . e) N, D$ O; {, _ Y Rnav - area navigation. A system of radio navigation which permits direct point-to-point off-airways navigation by means of an on-board computer creating phantom VOR/DME transmitters termed waypoints. 8 ^+ m! M8 T; s2 {1 U5 n B v* Z RON - remain over night (night-stop). 1 T5 V; y! `2 S: P" P $ }- U9 g; F% `8 p# o4 F- vroot - inner end of wing where it meets fuselage. rpm - revolutions per minute. r/t or RT - radio telephony. Voice communications, as opposed to WT, wireless telegraphy RTF - radio telephony. 9 a9 I, X4 K7 X L. w6 f RVR - runway visual range, a horizontal measurement of visibility along a runway. # t: E; O- Y+ i- b0 H- z8 ?rwy - runway. Rx - receiver. 7 ?7 r) N, r9 \7 QS 5 q/ I+ I1 s- d. {0 V' QSACP - (CAA) Standing Advisory Committee on Pilot Licensing. 8 R, R4 V# a. |# ~ SAR - search-and-rescue. Also Sarsat, SAR satellite. . L6 N" t8 l- ^ A; ~( CSAS - stability augmentation system. An automatic flight control system employed in many helicopters and some fixed-wing aircraft to enhance their stability and handling qualities. 7 p9 E Z) E a4 [SATCO - senior air traffic control officer satcoms - satellite communications, now being introduced on intercontinental airliners and business jets for (non- operational) air-to-ground voice communications via ground relay stations. 4 G2 `1 N, F1 }: l . p# j' U* J I8 ESB - Service Bulletin. Advisory notices issued by aircraft, engine and equipment manufacturers alerting owners and engineers to faults or problems requiring preventitive or remedial maintenance or modification. Often termed 'mandatory', but do not have the legal force of Airworthiness Directives (which see). SBAC - Society of British Aerospace Companies. The UK aerospace manufacturers' trade association. r- ^/ W$ k7 z' } J( N* ] 5 G7 T1 [ L/ d3 U. ^- tSDAU - Safety Data Analysis Unit of the CAA. # G7 D0 L; U1 e8 f . N9 \) `& B# W% v'second pilot' - unofficial term used to describe short (usually 8-10 hours) flying courses designed to enable non-pilot light aircraft passengers to take control and land in an emergency such as pilot incapacitation. Also standby or safety pilot and pinch-hitter (U.S.) Sectional - (U.S.) VFR navigation chart, equivalent to our 1:500,000 or 'half-million'. * X6 U% V" |0 u, j% b3 \ V# f 5 F/ J8 V/ h/ D+ A) ^5 D lSemi-circular - system of cruising altitudes. . h4 A9 l% Q1 z5 J( ]SELCAL - selective calling. A high-frequency system enabling air traffic control to alert a particular aircraft, by means of flashing light or aural signal in the cockpit, for receipt of a message without the crew having to maintain a listening watch. Used on long-haul over-ocean airline routes and by intercontinental bizjets. r, _, k" P0 B3 c6 y/ ~ L! j 7 t3 z Y8 O, [) nsfc - specific fuel consumption of an engine, expressed in pounds of fuel consumed for each unit of power (hp, shp, lb/st) produced. Also surface. short final - radio call made from aircraft calling later than final position, or on final approach from a shortened circuit, or at 2nm from threshold on a straight-in approach. ! F8 Y& ~; Q* ]4 {* j shp - shaft horsepower. SID - standard instrument departure. A standard IFR departure route enabling air traffic controllers to issue abbreviated clearances and thus speed the flow of traffic. 9 j4 `4 R) v% c7 o! u SIGMET - warning of severe weather conditions (active thunderstorms, hail, severe turbulence, icing etc.) issued my Met offices. 5 [5 B n9 W; d/ j0 e- o, ?sl - sea level. SLA - small light aircraft 5 B8 V6 X$ P9 Y! zSLMG - self-launching motor glider ; t3 ~& ]( \% c" v5 p, @SMOH - since major overhaul. Term used in aircraft for sale advertisements where engine hours are quoted (see TBO). Also STOH, TTSN, TTAF/E $ |' D! _) t$ i, Y( a9 y# n5 y" |9 Q. t$ w ! z+ J! j& X2 N1 R- JSMR - surface movement radar. 7 k& [5 b9 A' z$ X5 S , \& ~1 h1 B1 G3 v3 C0 VSNOWTAM - a NOTAM concerning runway conditions in snow. ) [! `# v, G, E $ ~' ?! f' [; A) }; [SOB - souls on board, the number of persons on board an aircraft. Also POB. 5 W/ w. E* }) E/ _. V( Z1 s* }socked-in - A colloquialism referring to an airport closed to air traffic by bad weather, similarly clamped. ( u( h# I9 i' U7 ~7 I, O& l 7 j, O0 s5 r# |% y( jSOP - standard operating procedure. + W" L0 V1 _/ X; xspecific range - measure of an aircraft's fuel efficiency, expressed as nautical miles flown per pound of fuel burned (nm/lb) 4 E8 q; h, E4 d; c7 Y# G! rSPL - Student Pilot's Licence. No longer issued in the UK, where a CAA medical certificate serves as an SPL. # `9 l7 E. s- n+ @1 x9 Q1 L0 n 6 C0 e+ i" i% W& k" D' h+ s8 gsquawk - to transmit an assigned code via a transponder (see SSR below). " n N* Z5 m: H' X1 ]/ @SR - sunrise. " M# f9 p3 ^) S3 u 9 }0 ~: s6 `/ U$ |' `( xSRG - Safety Regulation Group of the CAA 5 T z3 t, D( I" A6 X( b1 z( J/ DSRZ - Special Rules Zone. An area of protected airspace surrounding an airfield and extending from the surface upwards to a specific level which affords safety to air traffic movements in the vicinity of airfields whose traffic level does not warrant the establishment of a Control Zone. Also SRA, Special Rules Area. extending vertically and horizontally from a level above the surface, but not necessarily terminating at the same upper level as the SRZ. : l, G6 }5 j W: g : z6 M( }4 D' b/ g- q. WSRA - Surveillance Radar Approach. Also Special Rules Area. SRE - Surveillance Radar Element of a GCA. SS - sunset. SSB - single sideband. Reduction of bandwith by transmitting only one sideband and suppressing the other, and usually also the carrier wave. 2 |% u2 g- a2 LSSR - secondary surveillance radar. A radar system comprising a ground-based transmitter/receiver which interrogates a compatible unit in the aircraft (see transponder), providing instant radar identification without having to manoeuvre. Assigned four-digit transponder codes are referred to as squawk codes. : b' B. R$ S& U! I2 P5 Z1 |STAR - Standard Terminal Arrival Route, for inbound IFR traffic. # C5 H7 ]; H3 F1 X8 @$ S3 QSTC - Supplemental Type Certificate. U.S. system for post-type certification approval of aircraft modifications such as re- engining, STOL kits, etc, where the full certification process is not deemed necessary. Also used by manufacturers to certify (often greatly changed) new models of old types under so-called 'grandfather rights'. 3 U6 O8 r% Y2 ]; J7 d# YSTOH - since top overhaul 4 D. T6 G" D2 L4 p& N8 l STOL - short take-off and landing. Also VTOL, V/STOL, 7 g" A" E: h" E' ` STOVL - short take-off, vertical landing. ) B# J( t4 j0 I5 g6 i' p1 P' NT ! d0 j( ^- Y" O6 dT - true. Also TH, true heading, and TT, true track. . b* {1 |) t7 _" u7 C0 ]# R ( w" G. g; {! o q$ G3 Q8 pTACAN - tactical air navigation system. An ultra-high frequency electronic navigation aid which provides suitably-equipped aircraft with a continuous indication of bearing and distance to the selected Tacan station. The distance element can be received by civilian DMF equipment, but otherwise Tacan is principally a military navaid. 9 Q% K* v+ [( g5 m$ B( ]TAF - Terminal Area Forecast. 7 N& N+ ]2 A' C: Z+ ^ TAS - true airspeed. Rectified airspeed corrected for altitude and outside air temperature. 4 j2 Q2 k2 u/ `$ [+ {% C; ZTBO - time between overhauls, an engine manufacturer's recommended overhaul interval in hours, a rough and not guaranteed guide to life expectancy of an aero-engine before it will need overhaul. , i2 t: K' x& c, nTCA - Terminal Control Area (USA). ; s) L5 a! V9 U& L- O8 b TCAS - traffic alert and collision avoidance system. U.S. developed radar-based airborne collision avoidance system operating independently of ground-based equipment. TCAS-I generates traffic advisories only, TCAS-II provides advisories and collision avoidance instructions in the vertical plane. TEMPO - temporarily, term used in Met reports. 5 B/ u0 ?- z9 ^. ATET - turbine entry temperature. 4 ?5 V! Z6 s, I9 g* L' y: S TGT - turbine gas temperarture. ; I0 R1 ~! K4 o9 a+ Q7 E0 F THR or thld - threshold. - P8 m; C3 k5 g7 H$ d1 A 9 l6 f. \" y4 s" l3 ITMA - Terminal Control Area. An area of controlled airspace at the intersection of airways in the vicinity of control zones (CTRs) around major airports. 7 X3 |( t0 o5 U8 ]: l1 VTO - take-off (sometimes TKOF). 0 Q i; D6 {5 o: j0 A4 \ TODA - take-off distance available. Also TODR, take-off distance required, and TORA, take-off run available. # r, m! _; S1 K track - actual flight path of an aircraft over the ground. " ?% ^. d/ ~7 U6 `( k transponder - airborne receiver/transmitter portion of the SSR system which receives the interrogation signal from the ground and automatically replies according to mode and code selected. Modes A and B are used for identification, using a four-digit number allocated by air traffic control. Mode C gives automatic altitude readout from an encoding altimeter. 1 e9 a' p8 o. X x% l4 J - h% l* i9 j* T1 q6 K2 Stransition altitude (TA) - altitude in the vicinity of an aerodrome at or below which the vertical position of an aircraft is controlled by reference to altitude, i.e. with the aerodrome QNH set on its altimeter. Above transition altitude QNE is set and flight levels used. Also transition level (TL) at which a descending aircraft changes from FL to QNH. " A- `; U/ R+ s6 H" X4 t c7 btrend - Met forecast for the next two hours, added to some METARs. TSO - Technical Standard Order. A standard established by the U.S. FAA for quality control in avionics, instruments and other airborne equipment. If it complies, equipment is said to be 'TSO'd' and is more expensive than similar non-TSO's equipment. 2 J9 g% B& @' B: q% j4 t% D . x. a- W$ Y5 n) |7 f6 o6 oTTAF/E - total time airframe/engine, ! J* T( ?0 d; H1 h, ]" N1 v, ^3 CTTSN - total time since new TVOR - terminal VOR. A low-powered VOR located at or near an airport and used as an approach aid. % q8 l1 ]4 [( K( d/ }( s& A2 k ( u% o+ q0 s" H. v* Z qTWR - Tower (aerodrome control tower). 3 S' v; u! u# J" A% I; w TWY - taxiway. 2 C( s! }. ?0 I) K) c+ q3 k1 Z( cTx - transmitter. % f- {' d1 I2 d# e2 D; L 6 e% X( H3 @& htyro - Can be used as an r/t call prefix by inexperienced pilots in distress or urgency situations to ensure they are not passed instructions beyond their capabilities. , V# |+ y) n; N0 N U UAS - University Air Squadron. UDF - UHF direction finding. . M2 x- {" ~$ o / W% q K% h pUFN - until further notice. UHF - ultra-high frequency. Radio frequencies in the 300-3,000 MHz band. 8 E! U# I, k4 E- p) i6 i UHMRA - Upper Heyford Mandatory Radio Area. UIR - Upper Information Region, covering the same geographic areas as a FIR, but extending vertically upwards from 24,500 feet, within which certain additional operational rules apply. Also UIS, Upper Information Service. 8 h0 m: T1 W! L# kUnicom - privately-operated advisory A/G radio service at uncontrolled airfields (USA). UNL - unlimited u/s - unserviceable (i.e not working) when applied to an aircraft or its equipment. ' A" o5 y$ Q" d, L5 A9 mUTC - Co-ordinated Universal Time, formerly Greenwich Mean Time (see also Zulu). % \! Q! y( _, X5 x O+ n V + e2 n0 N+ {# `0 o% GV-speeds - designations for certain velocities relating to aircraft operation, thus: V1 decision speed, up to which it should be possible to abort a take-off and stop safely within the remaining runway length. After reaching V1 the take-off must be continued. Va design manoeuvring speed. The speed below which abrupt and extreme control movements are possible (though not advised) without exceeding the airframe's limiting load factors. 9 {& I, c0 K2 O9 b5 k+ x" IVfe maximum flap extension speed (top of white arc on ASI). Vle maximum landing gear extended speed s( e! ?3 w9 X! T) DVmca minimum control speed (air). The minimum speed at which control of a twin-engined aircraft can be maintained after failure of one engine. ) \& F3 H+ [! h$ E6 E1 e, tVmo maximum operating speed. Also Mmo, Mach limit maximum operating speed. Vne never-exceed speed, 'redline speed' denoted by a red radial on an ASI. 4 g. d4 h+ H7 Q3 C1 {% IVno normal operating speed. The maximum structural cruising speed allowable for normal operating conditions (top of green arc on ASI). 3 W! G6 G/ y+ o% |: QVr rotation speed, at which to raise the nose for take-off. : {3 v( D; ?5 Q( N% d9 s, A7 v7 LVso stalling speed at MTWA, in landing configuration with flaps and landing gear down, at sea level, ISA conditions (bottom of white arc on ASI). Vx best angle of climb speed on all engines. # `4 T& @7 K! F; H: h. [Vxse best engine-out angle of climb speed. Vy best rate of climb speed on all engines. Vyse best engine-out rate of climb speed, 'blueline speed' (blue radial on ASIs of light twins) VAL - visual approach and landing chart. - V0 o; @; r, K6 P d 8 z/ z- H a5 d( ^6 ^var - variation (magnetic) VASI - visual approach slope indicator VASIS - visual approach slope indicator system. A coloured light system providing visual guidance to the glidepath of a runway. VDF - very-high frequency direction-finding, whereby an aircraft's bearing from a ground receiving station may be determined from its RT transmissions. # k* v( c3 f' L . L6 N- |8 B/ l3 {* e/ v7 |1 o4 pvdu - visual display unit. VFR - Visual Flight Rules. Prescribed for the operation of aircraft in visual meteorological conditions (VMC).VMC is generally defined as five miles visibility or more and 1,000 feet vertical and one nautical mile horizontal clearance from cloud, but variations apply to aircraft operating below 3,000 feet amsl. Special VFR (SVFR) clearances are granted at the discretion of ATC for VFR flight through some controlled airspace where IFR usually apply. Also CVFR, Controlled VFR Flight. 2 k7 J1 q/ W$ p4 {$ Q7 vVGS - Volunteer Gliding School (RAF Air Cadets) ! q" g: \) P! }: p VHF - very high frequency. Radio frequencies in the 30-300 MHz band, used for most civil air-to-ground communication. 5 g4 q @6 I3 B3 q * Q" y! h+ a9 d) f% j+ K- h; M# N9 ?( {vis - visibility. VLA - very light aircraft ' H" p4 Y* ^+ f9 i- ~9 dVLF - very low frequency. Radio frequencies in the 3-30 kHz band. 7 @: q7 m% V) q3 JVLF/Omega - worldwide system of long-range navigation using VLF radio transmission. 8 _/ j5 ~5 R/ ?9 a2 B VMC - Visual Meterorological Conditions. See VFR, above. 9 p J3 `$ f* @" g9 iVnav - vertical navigation. 3 d8 h7 `1 M; |! FVne - never exceed airspeed $ r& L/ M. T4 t) S! n5 W ) c/ W% b) C3 ZVolmet - continuous recorded broadcasts of weather conditions at selected airfields. VOR - very high frequency omnidirectional range. A radio navigation aid operating in the 108-118 MHz band. A VOR ground station transmits a two-phase directional signal through 360ø. the aircraft's VOR receiver enables a pilot to identify his radial or bearing from/to the ground station. VOR is the most commonly used radio navigation aid in private flying. Increased accuracy is available in Doppler VORs (DVOR) which have replaced some VOR is the UK system. Also VORTAC, combined VOR and TACAN, and VOT, VOR test facility. - L4 ?1 u v! v - ]9 k# U. M" k$ i. ^. l8 YVP - variable-pitch (propeller), whose blade angle can be altered in flight either automatically or manually. p4 ?8 n/ p( A ! q% M% i7 |8 o, ?/ J9 uVr - Rotation speed ( v) h6 c# h% q9 q 3 A/ z0 {6 x4 B( DVRP - visual reference point. (In the UK) Landmarks used for position reporting by aircraft operating VFR. / T# _$ x0 M7 x/ h: q! }& b 9 A/ L! _8 L2 \6 FVSI - vertical speed indicator. One of the primary flight instruments showing rate of climb or descent. Also IVSI, instantaneous VSI. * O7 l( L9 b8 l N5 C7 I/ j1 a" C# Z( BV/STOL - vertical/short take-off and landing ) p9 J1 y& L- E9 D9 y VTOL - vertical take-off and landing. VTR - vocational training relief. Tax releif granted by the Inland Revenue against the cost of certain commercial pilot training courses. : ?7 Q" Y% W& [& \" ^0 x' @( }; Y( }; bW wake turbulence - wingtip vortices generated behind a wing producing lift. Behind a large heavy aircraft they can be powerful enough to roll or even break up a smaller aircraft. " M) }+ A9 @0 l: T' Q& p$ N 9 Y) B$ ?) @* _3 C% H/ sWAT - weight-and-temperature. " W# F9 B) A/ A, e+ V w.e.f. - with effect from. Also w.i.e., with immediate effect. 2 B/ Q4 U$ R! R l 7 U2 L2 x0 `% h& Z b0 wwet - when refering to aircraft hire charges means 'fuel included' * W1 _* K9 J* u- r6 i( m% } wind shear - localised change in wind speed and/or direction over a short distance, resulting in a tearing or shearing effect, usually at low altitude, that can cause a sudden loss of airspeed with occasionally disastrous results if encountered when taking-off or landing. / n! M r6 ~) b; q9 G8 k3 n oWIP - work in progress. o$ V/ {+ ]9 t+ m7 J$ j& A$ c! s7 X) RWP - waypoint. wt - weight 2 {8 x8 h/ C& I- S- VWx - weather. 1 c, P d' K) s. j% _: _, g/ r 1 @" M5 W) K" S }3 ?# W" V+ DWX NIL - no significant weather, term used in Met reports. ' U2 [) D. H$ ^ . J- m, K6 w3 N+ s5 @+ [: tX 6 F" N1 ?5 S" Y4 e3 s! G6 mXC - cross-country . s& t/ @0 k0 s% X [% I) n9 O % m+ m% k' ^) [xmsn - transmission. ; u, Y5 J9 ]' G* e+ Z$ W7 n& F$ E / K- \- v- c) [6 vxpdr - transponder. Y 8 T0 G( S( r' O4 _ n" ?, [. }Z zero-fuel weight - maximum permissible weight of an aircraft beyond which an additional load must be in the form of fuel (i.e. max take-off weight less total usable fuel in applicable aircraft, which are so limited because of the wing-bending moments associated with near-empty wing fuel tanks). 8 V7 G6 N; F# N; c6 O/ \zero-timed - overhauling an aero-engine to 'service limits' (not the same 'good as new' or factory remanufactured). Zulu or Z - used worldwide for times of flight operations, formerly Greenwich Mean Time, now Co-ordinated Universal Time (UTC). & X; t O( F, ~& H# I 4 S8 x% F. i* }" D7 e1179 3 `. Y% s* L: T$ W& X$ o+ P' z2 a $ u& V" {+ d& u5 F2 T5 R1179 - flight test to add a new aircraft type to a professional licence, actually the reference number of the test form used

帅哥

A 
AAC - Army Air Corps

AAIB - Air Accident Investigation Branch of the Department of the Environment, Transport and the Regions.

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aae - above aerodrome elevation. Also see aal.

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aal - above aerodrome level. Also see aae.

ab initio - elementary flying training, literally 'from the beginning',.

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abm abeam - an aircraft is abeam a point when that point is at ninety degrees left or right of the aircraft's track, but term usually used to indicate a general position rather than a specific point.

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a/c - aircraft.

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ACARS - Aircraft Communication Adressing and Reporting System.

AC - alternating current.

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ACC - Area Control Centre. And ACZ Aerodrome Control Zone. See ATZ below.

ACMS - aircraft condition monitoring system.

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ACR - aerodrome control radar.

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accelerate-stop distance - calculated distance required for an aircraft to accelerate to V1 (which see), reject take-off and brake safely to a halt.

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A/D - aerodrome.

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AD - Airworthiness Directive, issued by airworthiness authorities to correct a defect found in an aircraft type after certification. Compliance is mandatory and may be required immediately and before further flight, within a specified period of time or number of flying hours, or when next due for routine maintenance.

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ADA - Advisory aispace - Advisory Area or Advisory Route.

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ADC - air data computer.

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ADELT - automatically deployable emergency locator transmitter.

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ADF - automatic direction finder/finding. Radio compass which gives a relative bearing to the non-directional radio beacon to which it is tuned.

ADI - attitude deviation indicator. An advanced type of artificial horizon, part of a flight director system providing pitch and roll information and commands.

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ADIZ - Air Defence Identification Zone. An area of airspace extending upwards from the surface, usually along a national boundary, within which identification of all aircraft is required in the interests of national security.

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ADR - Accident Data Recorder.

ADS - Automatic Dependence Surveillance.

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ADT - Approved Departure Time.

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AEF - Aerodromes Environmental Federation.

AEW - Airborne early warning

Aerad - UK-published flight guide and navigational chart system.

aerodrome/airport elevation - highest point of an aerodrome's usable runway(s) expressed in feet above mean sea level (amsl).

AFB - air force base, usually U.S. or Canadian.

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AFCS - automatic flight control system, an advanced autopilot. Also IFCS, integrated flight control system.

AFDS - Autopilot and flight director system.

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AFI - assistant flying instructor. Also AFIC, assistant flying instructor course, FIC, flying instructor course.

AFIS - Aerodrome Flight Information Service, providing information to, but not control of, aircraft using that aerodrome. 

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AFIS(O)- Aerodrome Flight Information Service (Officer)

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AFS - Aerodrome Fire Service.

AFS - Aeronautical Fixed Service - telephone/teleprinter network, includes AFTN.

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AFS - auto flight system.

AFTN - Aeronautical Fixed Telecommunications Network. A ground- based teleprinter network transmitting flight plans, weather information etc.

AGO -  air-to-ground operator

A/G - air-to-ground.

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agl  - above ground level.

AHRS - attitude-heading reference system. A sensor deriving aircraft attitude and heading information from gyros and accelerometers.

AIAA - area of intense aerial activity, usually military.

AIC - Aeronautical Information Circular. Bulletins issued at intervals by the CAA relating to matters of airworthiness, administration, operating procedures, safety etc. AICs are colour-coded according to subject, e.g. safety circulars are pink, thus 'Pink 12' issued in December 1990.

AIDS - Airborne integrated data system.

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AIP - Aeronautical Information Publication. The UK Air Pilot, statutory bible of aeronautical information published by the CAA.

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Airep - form for reporting position and Met conditions in flight.

Airmet - CAA's telephone aviation weather service, covering Southern, Northern and Scottish regions of the UK. Also Metdial and Metplan, privately-operated aviation weather services. For full details see Pilot, February 1991.

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AIS - Aeronautical Information Service. CAA unit based at London-Heathrow Airport, providing flight-planning services and information for pilots. Publishes AICs, above.

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AIZ - Aerodrome Information Zone. See ATZ below.

ALERFA - alert phase of search-and-rescue procedure.

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alt - altitude. Height above sea level.

alternate - aerodrome specified on a flight plan to which an aircraft chooses to divert if a landing at its intended destination is not possible (for reasons of poor weather, for example).

altimeter setting - barometric pressure reading in millibars, hectopascals or (in USA) inches of mercury (Hg) used to set a pressure altimeter's sub-scale to QFE or QNH .

AM - Amplitude modulation.

AME - authorized medical examiner. A doctor approved by the CAA (or foreign licensing authority) to conduct examinations for the issue or renewal of aircrew medical certificates.

amsl  - above mean sea level (sometimes asl in USA).    

anhedral - sloping down from root to tip. Opposite: dihedral.

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ANO - Air Navigation Order. Statutory legal instrument defining the laws of air navigation, pilot licensing etc, in the UK. Other aviation legislation includes the Rules of the Air and Air Traffic regulations and the Air Navigation (General) Regulations

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AoA - angle of attack. Also alpha, thus 'high alpha', high angle of attack.

AOA - Airport Operators' Association.

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AOC - Air Operator's Certificate, issued by the CAA and required by aircraft operators flying scheduled or charter public transport flights, including cargo, air-taxi and pleasure-flying work. Also Air Officer Commanding in RAF parlance.

AoE - airport of entry (usually in USA).

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AOG - aircraft on ground, a term used to denote urgency when requesting spares or service from suppliers or manufacturers, meaning that the aircraft cannot fly again until the parts have been supplied.

AOPA - Aircraft Owners and Pilots Association.

A/P - airport or autopilot.

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A & P - Airframe and Powerplant Mechanic (USA).

APA - Aerodromes Protection Agency, the federation of associations for the advancement of British general aviation facilities.

APHAZ - Aircraft Proximity Hazards Assessment Panel, which investigates near-miss reports filed by air traffic controllers (see also JAWG).

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APP - Approach (control).

APU - auxiliary power unit. Large transport aircraft and some business jets have an APU, typically a small turbine, to provide power for engine-starting and for running systems when on the ground, obviating the need for external power or ground power unit, GPU.

ARB - Airworthiness Review Board.

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ARCAL - aircraft radio control of aerodrome lighting.

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Aresti - key shorthand notation system devised by Spaniard José L Aresti whereby aerobatic display routines or competition sequences can be drawn up on paper like a musical score. Now largely superseded by the simpler FAI Aerobatic Catalogue system.

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ARINC - Aeronautical Radio Incorporated. A non-profit corporation owned by airlines to set standards for airline avionics and provide communications services.

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ARP - aerodrome reference point.

articulated rotor - blades can flap, drag and feather.

ARV - air recreational vehicle.

ASDA - accelerate-stop distance available.

ASI - airspeed indicator, a flight instrument which measures the speed of an aircraft through the air.

ASR - altimeter setting region, a geographical area for which the lowest value of QNH  is forecast hourly and relayed by air traffic control centres. Also airport surveillance radar and air-sea rescue.

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ASTOVL - advanced short take-off and vertical landing.

ATA - actual time of arrival. Also Air Training Association.

ATC - air traffic control.  

ATCA -  air traffic control assistant

ATC(C) - air traffic control centre;

ATCO - air traffic control officer..

ATIS - automatic terminal information service, a continuous recorded broadcast of routine non-control airport information, usually at large airports.

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ATPL - Air Transport Pilot's Licence, needed to act as pilot-in- command of a commercial air transport aircraft exceeding 20,000 kg all-up weight.

ATO - assisted take-off e.g. J(et) or (R)ocket assisted.

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ATS - air traffic service. Also ATSU, ATS Unit.

ATSORA - air traffic services outside regulated airspace.

ATC(U) -  air traffic control unit.

ATZ  - Aerodrome Traffic Zone. An area of protected airspace surrounding an aerodrome bounded by a circle of 2 nm or 2.5 nm radius (depending on runway length) centred on the mid-point of the longest runway. Permission is required for entry into and movement in an ATZ.

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AUW - all-up weight, a term for the total loaded weight of an aircraft, made up of empty weight plus useful load; maximum auw is the maximum allowable weight, including fuel and payload, specified in an aircraft's Certificate of Airworthiness. Sometimes referred to (in USA especially) as gross weight and maximum gross weight respectively. Also MTWA, maximum total weight authorised; BOW Basic operating weight, the weight of an aircraft with all equipment, lubricants, fuel and operating crew, but without payload; MLW, maximum landing weight, above which fuel must be burned off or jettisoned before landing or there may be risk of structural damage.

avgas - aviation gasoline, usually followed by the octane rating. Used by piston-engined aircraft. Also LL, low lead.

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avtur - aviation turbine fuel (kerosene). Used by turboprops and jets.

AWR - airborne weather radar.

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Awy - airway.

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B     
BA  -  British Airways

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BAA - British Airports Authority.

BAeA - British Aerobatic Association.

BALPA - British Airline Pilots Association.

base leg - The crosswind segment of an aerodrome circuit bringing the aircraft from the downwind leg to final approach

BAUA - Business Aircraft Users Association.

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BCAR - British Civil Air Requirements. Airworthiness standards laid down by the CAA for certification of aircraft on the UK Civil Aircraft Register.

BCP - break cloud procedure.

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BCPL - Basic Commercial Pilot's Licence, the minimum qualification necessary in the UK to receive payment for acting as a pilot. Also CPL, Commercial Pilot's Licence, and SCPL, Senior Commercial Pilot's Licence (no longer issued).

beta mode - manually-controlled mode for CS propellers on turboprop aircraft enabling reverse pitch to be selected for braking or to aid ground manoeuvring.

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BFR - Biennial Flight Review (USA). Holders of U.S. FAA Private Pilot Licences must undergo a flight check with an FAA-approved examiner every two years. No UK equivalent.

BGA - British Gliding Association.

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BHAB - British Helicopter Advisory Board.

bhp - brake horsepower.

BHPA - British Hang-Gliding and Paragliding Association.

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Bleed air - Hot compressed air taken from turbine engines.

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BMAA - British Microlight Aircraft Association.

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Bottlang - Loose-leaf Euopean airfields manual for VFR operations.

BRG - bearing, the horizontal direction to or from any point expressed in degrees of the compass.

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BWPA - British Women Pilots Association.

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C  
C - Celsius (temperature) or compass.

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CAA - Civil Aviation Authority.

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CAD/CAM - computer-aided design/manufacture.

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CAAFU - Civil Aviation Authority Flying Unit, based at Stansted Airport, which performs such tasks as navaid checking and calibration and also examines candidates for instrument ratings and commercial pilot's licences.

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CANP - Civil Aviation Notification Procedure. A voluntary system whereby civil operators notify their intention to fly at low level (at or below 1,000 feet agl, when crop-spraying or powerline inspecting for example), aimed at avoiding conflict with low-flying military aircraft.

CAP - Civil Air Publication. Information booklets issued by the CAA, e.g. CAP 53 The Private Pilot Licence.

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CAS - calibrated airspeed -- indicated airspeed corrected for air density and compressibility.

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casevac - casualty evacuation.

CAT - clear-air turbulence. Also CATegory when referring to certain instrument landing systems which require special aircraft instrumentation, certification and pilot qualification beyond those needed for standard instrument approaches (e.g. a CAT IIIC ILS permits operation down to the surface of the runway without external visual reference, true zero-zero operation).

CAVOK - pronounced CAV-okay (ceiling and visibility OK), visibility at least ten kilometres, with no cloud below 5,000 feet, with no Cbs, precipitation, thunderstorms, shallow fog or low drifting snow.

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CAVU - ceiling and visibility unlimited. Cloudless (or scattered cloud) conditions with visibility in excess of ten kilometres.

CCF - Combined Cadet Force

CDI - course deviation indicator. The vertical needle of a VOR indicator which shows the aircraft's position relative to the selected VOR radial.

CDU - control display unit.

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ceiling - height above ground or water of the base of the lowest layer of cloud below 20,000 feet which covers more than half of the sky. An aircraft's service ceiling is the density altitude at which its maximum rate of climb is no greater than 100 feet per minute. Its absolute ceiling is the highest altitude at which it can maintain level flight.

CFI - chief flying instructor (certified flying instructor in USA).

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CFS - Central Flying School (RAF)

CG - centre of gravity

CH - compass heading.

Check 'A' - a thorough pre-flight inspection - the first of the day.

CHIRP - Confidential Human Factors Incident Reporting system, whereby professional pilots and ATC staff may report in confidence incidents arising from human errors for analysis by the CHIRP Charitable Trust at Farnborough.

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CHT - cylinder head temperature (gauge). A device which, by means of a probe(s) gives a cockpit readout of the temperature of one or more of an aircraft engine's cylinder heads.

circuit - pattern around which aircraft fly when arriving at an airfield, usually rectangular in UK but not necessarily elsewhere. The circuit (known as the pattern in USA) is aligned with the active runway and may be either left- or right-handed. Dead side is the opposite side of the circuit pattern in operation from which arriving aircraft join for landing. See also final(s).

C/L - centre-line (of a runway, for example).

clamped - colloquialism referring to an airport closed to air traffic by bad weather

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clean - flaps, slats and undercarriage retracted and on military aircraft no external missiles etc.

clearance - authorization from air traffic control to proceed as requested or instructed. Used for ground and air manoeuvring, thus "cleared for take-off", "cleared flight-planned route", "cleared to descend" etc.

Clouds - commonly-used abbreviations for cloud types:

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AC = altocumulus 
AS = altostratus 
CB = cumulonimbus 
CC = cirrocumulus 
CI = cirrus 
CS = cirrostratus 
CU = cumulus 
NS = nimbo stratus 
SC = stratocumulus 
ST = stratus 
C of A - Certificate of Airworthiness issued by the CAA indicating that an aircraft meets the Authority's airworthiness standards. Cs of A are issued to individual aircraft, and also to generic aircraft types (Type Certification in the USA) when the first example of a type is registered. Cs of A on individual aircraft are granted in several categories, e.g. Private, Public Transport, Aerial Work etc. and much be renewed at intervals. Permits to Fly are authorisations granted to specialist aircraft  and are accordingly restricted in the kinds of operation for which they may be used.

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C of E - Certificate of Experience, valid for private pilot licence holders for thirteen months, and renewed by flight test or evidence of completing the minimum required flying experience in the preceding thirteen-month period. Also C of T, certificate of test.

C of G - centre of gravity. The point on an aircraft through which the entire aircraft's weight may be assumed to act (i.e. around which the aircraft, if suspended, would balance). C of G limits are the most forward and rearward positions of the C of G permitted for safe operation. An aircraft loaded outside its C of G limits can be difficult or impossible to control.

C of P - centre of pressure, the point through which the total effect of lift may be said to act on an aeroplane.

Com(m)(s) - communication(s)

CPL - Commercial Pilot's Licence

CR or C/R - counter-rotating. Usually in general aviation referring to twin-engined aircraft with 'handed' engines whose propellers turn in opposite directions to eliminate propeller torque effect.

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CRM - cockpit resources management

crosswind (leg) - portion of an aerodrome circuit flown before downwind

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CRP - compulsory reporting point.

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CRT - cathode ray tube (like a television). Used in flight deck displays of new-generation airliners, business aircraft and military jets instead of conventional instruments. See also EFIS,.

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critical altitude - the highest density altitude at which it is possible to maintain the maximum continuous rated power or manifold pressure of an aero engine.

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critical engine - the engine on a multi-engined aircraft whose failure would most seriously effect performance or handling of the aircraft, through asymmetric effects or loss of power to systems such as hydraulics.

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CRS course - the intended direction of flight in the horizontal plane expressed in degrees of the compass.

c/s - call sign.

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CS - constant-speed (propeller). A variable-pitch propeller which maintains constant rpm by automatically changing blade angle. Also CSU, constant-speed unit.

CTA - Control Area. An area of controlled airspace extending upwards from specified limit agl.

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CTR - Control Zone. An area of controlled airspace extending upwards from ground level to a specified upper limit.

CVR - cockpit voice recorder. A tape recorder installed on the flight decks of commercial transport aircraft and helicopters and some business aeroplanes to record crew conversation, RT transmissions and cockpit background noises (e.g. trim-wheel operation, flap motor running) in case required for incident or accident investigation.

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CW - carrier wave or continuous wave.

CWR - colour weather radar.

CZ - Control Zone (USA).

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CZI - compressor zone inspection.

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D     
DA - Danger Area.

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DAAIS - Danger Area Activity Information Service.

DACS - Danger Area Crossing Service.

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DADC - Digital air data computer (DADS - /system).

D & D - Distress & Diversion Cells at Air Traffic Control Centres. RAF units which provide a 24-hour listening watch on VHF and UHF emergency frequencies and can locate and assist pilots who are lost or in emergency situations.

dB - decibel(s) - a unit of sound

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DC - direct current

DCT - direct

dead side - opposite side of an airfield circuit pattern from which aircraft join for landing

deadstick - descent and landing with engine(s) shut down and propeller(s) stopped.

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Decca - hyperbolic area navigation system, originally developed for maritime use, based on signals received from a chain of master and slave ground stations located in northern Europe.

DEEC - digital electronic engine control

density altitude - pressure altitude corrected for air temperature.

derated - engine's potential power deliberately limited, lengthening likely life.

DETRESFA - distress phase of search-and-rescue operation.

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DF - direction-finding. A DF bearing can be provided by airfields or other facilities such as D & D cells (above) having suitable direction-finding equipment to locate an aircraft.

DG - Directional gyro

DGAC - Direction Général à l'Aviation Civile

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DH - decision height. The height on a precision approach at which a pilot must have the runway approach lights in sight to continue the descent, or if not, must initiate a go-around.

DHFS - UK Defence Helicopter Flying School at RAF Shawbury

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DI - direction indicator. A gyro instrument which indicates the magnetic heading of an aircraft. The DI, also known as the directional gyro (DG), is free of the turning errors associated with magnetic compasses but is prone to precession (wander) and must be reset against the magnetic compass at intervals. ALSO -
DI - is also used to refer to the daily inspection -- a thorough pre-flight check of an aircraft prior to the first flight of the day.

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dihedral - sloping up from root to tip. Opposite: anhedral.

DIN(S) - digital interial navigation (system).

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DME - distance-measuring equipment. A combination of ground and airborne equipment which gives a continuous slant range distance-from-station readout by measuring time-lapse of a signal transmitted by the aircraft to the station and responded back. DMEs can also provide groundspeed and time-to-station readouts by differentiation.

Doppler - Doppler effect (or shift) is the change in frequency of light, radio or sound waves when source and receiver are in relative motion.

DoT - Department of Transport.

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downwind - The segment of an aerodrome circuit paralleling the active runway and flown on a reciprocal heading

DP - dew point

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DR - dead (deduced) reckoning. Plotting position by calculating the effect of speed, course, time and wind against last known position.

dry - when referring to aircraft hire charges means 'without fuel', as opposed to wet, with fuel.

DZ - dropping zone, for parachuting etc.

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E
EAA - Experimental Aircraft Association, the American homebuilders' organisation.

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EADI - electronic attitude director indicator. An ADI with CRT cockpit display forming part of an EFIS, below.

EAS - equivalent airspeed.

EAT - estimated (or expected) approach time.

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EBAA - European Business Aircraft Association.

ECAC - European Civil Aviation Conference.

ECOGAS - European Council of General Aviation Support.

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ECU - environmental control unit.

ED - emergency distance.

EET - estimated elapsed time.

EFAS - electronic flash approach light system.

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EFATO - engine failure at (or after) take-off.

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EFIS - electronic flight instrument system, in which multi- function CRT displays replace traditional instruments for providing flight, navigation and aircraft systems information, forming a so-called 'glass cockpit'. Now common in commercial transports, corporate aircraft and helicopters, military fighters and some GA piston singles and twins.

EGT - exhaust gas temperature (gauge). A device which provides a cockpit readout of the exhaust gas temperature of an aircraft's (piston) engine(s), enabling the pilot to lean the mixture for maximum fuel efficiency.

EHSI - electronic horizontal situation indicator. CRT-based HSI forming part of an EFIS.

EICAS - engine indication and crew alerting system. CRT display which monitors engine performance and alerts the crew to system or airframe failure. Found in new-generation transports and business jets.

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EICMS - engine in-flight monitoring system

ELT - emergency locator transmitter. A small radio transmitter fixed to an aircraft's structure which is automatically activated by impact or water immersion and transmits a code on emergency frequencies enabling SAR satellites or search units equipped with DF to locate the crash or ditching site. Carriage mandatory in the USA, but not in UK. Sometimes styled ADELT, automatically deployable ELT, or ELB, emergency locator beacon.

empty weight - weight of the basic aeroplane including all fixed equipment, plus unusable fuel, oil, hydraulic and other fluids.

encoding altimeter - an altimeter which gives a digital output to the transponder (which see) for automatic transmission of the aircraft's pressure altitude to ATC.

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EOBT - estimated off-blocks time.

EP - Elementary pilot rating of the British Hang Gliding and Paragliding Association

EPNdB - effective perceived noise decibel. Unit of measurement of aircraft noise levels.

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ER - extended range.

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eshp - equivalent shaft horsepower.

ETA - estimated time of arrival. Also ; 

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ETD - estimated time of departure

ETE - estimated time en route.

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ETOPS - extended-range twin operations, usually long over-water flights by airliners.

ETPS - Empire Test Pilots School, based at the Aircraft & Armament Experimental Establishment, Boscombe Down.

Eurocontrol - organisation, headquartered in The Netherlands, comprising Belgium, France, Germany, Ireland, Luxembourg, Netherlands and UK for coordinating en route air traffic control in Europe.

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

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

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FADEC - full-authority digital engine control.

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

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

FAR - Federal Aviation Regulations (USA).

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FARA - Formula Air Racing Association.

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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.

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

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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.

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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.

FIC - Flight Information Centre.

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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.

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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.

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.

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

FLG - flashing.

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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.

FLIR - forward-looking infra-red.

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FLM - foot-launched microlight.

FLPA - foot-launched powered aircraft, e.g. powered parachutes.

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FM - frequency modulation.

FMC/S - flight management computer/system

FMGC - flight management guidance computer.

FMS - flight management system.

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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.

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FSS - Flight Service Station (USA).

FTO - flying training organisation.

FTS - Flying Training School (RAF)

ft/min - feet per minute

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G
g - the acceleration force of gravity, normally 1g on earth. Zero g (0g) is weightlessness, as experienced by orbiting astronauts. g is expressed as positive (+) and negative (-) values. During a normal loop a pilot experiences positive g, tending to force him down in his seat. In an outside loop, with the pilot's head on the outside of the vertical circle, negative g forces him up against his straps. Aircraft structural load limits are expressed in positive and negative values, the positive limit usually greater than negative, except in specialist aerobatic types.

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g-loc - g-induced loss of consciousness. Pilot blackouts caused by excessive g or by too-rapid onset of g-forces. Experienced mostly by pilots of high-performance military jets and competition aerobatic aircraft, has led to fatal crashes.

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GA - general aviation, all flying other than airlines and the military.

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GAAC - General Aviation Awareness Campaign.

GAFOR - General Aviation Visual Flight Forecast. Met briefing service in operation in France, Germany, the Netherlands and some other European countries.

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gall imp/U.S. - gallons, imperial or USA. One imp gall = 1.201 U.S. gall.

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GAMA - General Aviation Manufacturers Association, an American trade organisation.

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GAMTA - General Aviation Manufacturers & Traders Association, UK.

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GAPAN - Guild of Air Pilots and Air Navigators.

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GASCo - General Aviation Safety Council

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GASIL - General Aviation Safety Information Leaflet. Monthly safety and accident prevention bulletin for pilots and engineers published by the CAA.

GCA - ground-controlled approach. A landing approach in which a ground controller gives verbal guidance in azimuth and elevation to a pilot using precision approach radar (PAR) to monitor the aircraft's approach path. Still used by the military, but defunct in civil aviation.

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GFT - General Flying Test, taken by student pilots to qualify for the PPL, and also by candidates for the BCPL and CPL. Also NFT, navigation flight test, which is part of the practical examination for the PPL.

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Glonass - Russian equivalent of GPS/Navstar satellite navigation system.

glove - non-movable part of a variable geometry wing.

gnd - ground

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GNSS - Global Navigation Satellite Systems.

go-around to climb away from a runway after making an approach, either to make a further attempt at landing or to divert to an alternate airport (formerly 'overshoot').

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Goxio - VHF direction-finding (France)

GP - glidepath

gph - gallons per hour, an expression of fuel consumption or fuel flow (FF) in either imperial or U.S. gallons. Usually lb/hr for turbine-powered aircraft.

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GPS - Global Positioning System (Navstar). A U.S. developed satellite-based high-precision navigation system, intended primarily for military use but now in widespread use by commercial and private operators, though with reduced accuracy compared with military versions.

GPWS - ground proximity warning system. A radar-based flight- deck system to give pilots audible warning by means of horns, hooters, taped or synthetic voices of terrain close beneath an aircraft's flight path.

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GRADU - gradual (term used in Met reports).

GRP - glassfibre-reinforced plastic; also CFRP, carbon-fibre reinforced plastic. Composite materials seeing increasing use in entire airframes for GA aircraft (e.g. Beech Starship) and for components for helicopters, airliners and military aircraft.

GS - glideslope. The vertical guidance part of an instrument landing system which establishes a safe glidepath (usually three degrees) to a runway.

G/S - groundspeed. The speed an aircraft makes over the ground, a product of its airspeed and wind speed.

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H 
H24 - continuous round-the-clock operation. Also HJ operates during day; HN operates during night; HO operates during times to meet operational requirements, and HX no specific operational hours.

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HAA - Historic Aircraft Association.

HAI - Helicopter Association International.

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half-mill(ion) - 1:500,000 scale ICAO aeronautical chart.

Hdg - heading. The direction in which an aircraft's nose points in flight in the horizontal plane, expressed in compass degrees.

Heavy - suffix used in RT callsigns to indicate that the aircraft is a large transport, alerting controllers and following aircraft to the possibility of wake turbulence .

Hectopascal (hPa) - unit of pressure measurement, equivalent to one millibar (which see), now the ICAO-standard for altimeter setting.

HEMS - helicopter emergency medical services.

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Hertz - standard radio equivalent of frequency in cycles per second. See also kHz and MHz.

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HF - high-frequency band, used for long-range radio communications in the 3-30 MHz range.

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Hg - inches of mercury, a unit of pressure measurement.

HIAL - high intensity approach lighting.

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HIGE - hover in ground effect. Also see HOGE.

HIRF - high intensity radiated (electromagnetic) fields.

HIRL - high intensity runway lighting.

HISL - high intensity strobe light.

holding pattern - racetrack-shaped manoeuvre which keeps aircraft within a specified airspace while awaiting further clearance from air traffic control.

HOCAC - hands on cyclic and collective - see HOTAS below.

HOGE - hover out of ground effect. Also see HIGE.

hot-and-high - airfield conditions of high altitude and high ambient temperatures that can severely limit aircraft performance. See also density altitude.

HOTAS - hands on throttle and stick. Ergonomic cockpit design technology, originally developed for military combat aircraft, enabling a pilot to fly the aircraft and manage all navigation, weapons and other systems from control column/throttle lever hand grips.

HOTCC - hands on throttle, collective & cyclic - see HOTAS above.

hp - horsepower.

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HRA - Highlands Restricted Area

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hrs - hours

HSD - horizontal situation display.

HSI - horizontal situation indicator. A cockpit navigation display, usually part of a flight-director system, which combines navigation and heading.

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HUD - head-up display. A method of projecting instrument readouts or data which enables a pilot to see them while looking through the aircraft's windscreen. Mostly used on military aircraft, but now in service on some commercial airliners.

Hz - Hertz.

I
IAOPA - International Council of Aircraft Owners and Pilots Associations

IAS - indicated airspeed. An aircraft's speed through the air as indicated by the ASI, without correction for position error, altitude or outside air temperature. Also see CAS, RAS and TAS.

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IATA - International Air Transport Association.

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i/c - intercom

ICAO - International Civil Aviation Organisation.

IF - instrument flying. Also intermediate frequency.

IFF - identification friend or foe.

IFR - instrument flight rules prescribed for the operation of aircraft in instrument meteorological conditions (see below). Flight in most controlled airspace in the UK is conducted under IFR or Special VFR. Also used by military to denote in-flight refuelling.

IGE - in ground effect. Helicopter performance with an earth surface immediately below. Also OGE, out of ground effect. Helicopters can hover at a greater maximum altitude IGE (above a mountain slope, for example) than they can in free air, OGE.

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IGS - instrument guidance system.

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ILS - instrument landing system. The approach aid employing two radio beams to provide pilots with vertical and horizontal guidance during the landing approach. The localiser provides azimuth guidance, while the glide-slope defines the correct vertical descent profile. Marker beacons and high intensity runways lights are also part of the ILS.

IMC - instrument meteorological conditions: weather below VMC minima, see below. Also associated rating used in conjunction with UK PPL.

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INCERFA - uncertainty phase of search-and-rescue procedure.

INS - inertial navigation system. A gyroscope-based system which senses acceleration and deceleration and computes an aircraft's position in latitude and longitude with great accuracy. Used mostly by long-haul airliners, military aircraft and sophisticated business jets. Also IRS, inertial reference system.

INTER - intermittent or fluctuating, term used in Met reports.

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IR - Instrument Rating

IRAN - Inspect and repair as necessary

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IRE - Instrument Rating Examiner

IRT - Instrument Rating Test

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ISA - International Standard Atmosphere -- a set of standard conditions or temperature and pressure which serve as a basis for comparison. ISA = pressure 1013.2 millibars, temperature 15 degrees C. Aircraft performance figures quoted by manufacturers are often based on such a 'standard day'.

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ITT - inter-turbine temperature. Also TGT, turbine gas temperature TIT, turbine inlet temperature.

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IWR - Instrument weather rating. Proposed by the JAA as a replacement for the UK's unique IMC rating

J  
JAA - Joint Aviation Authority.

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JAR - Joint Aviation Requirements, being drawn up by eighteen European states, aimed at unifying airworthiness, flight crew licensing and other criteria among signatory nations.

JAWG - Joint Airmiss Working Group. A civilian/military committee which reviews and reports on all airmisses which occur in UK airspace.

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JEFTS - Joint Elementary Flying Training Squadron based at RAF Barkston Heath, Lincolnshire

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Jeppesen - U.S.-developed navigational/approach chart system with worldwide coverage, similar to British Aerad system.

JPATS - Joint Primary Aircraft Training System. A USAF/U.S. Navy programme to select a common aircraft design as a basic pilot trainer for the two services, due to be decided next year.

K 
kg -  kilogram(s)

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kHz - kilohertz, the frequency of a radio carrier wave measured in thousands of cycles per second. 1 kHz = 1,000 Hertz.

KIAS - knots indicated airspeed.

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km - kilomrtre(s)

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knot (kt) - one nautical mile per hour (never one knot per hour), the standard unit of aviation speed measurement. One knot equals 1.1515 mph; one nautical mile equals 6,080 feet.

kV- kilovolt

kW - kilowatt.

L 
LARS - Lower Airspace Radar Advisory service, available to all aircraft flying in uncontrolled UK airspace from 3,000 feet amsl to FL95. See also MMARS, RAS and RIS, below.

LAMS - Light Aircraft Maintenance Schedule, the CAA-approved schedule for fixed-wing light aircraft below 2,730 kg auw whose Cs of A are valid for three years subject to compliance with LAMS.

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lat - latitude.

LATCC - London Area & Terminal Control Centre at West Drayton, near Heathrow.

lb - pound(s)

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lbf - engine thrust in pounds force

LCD - liquid crystal display

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lczt - (ILS) localizer (USA)

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l/d ratio - lift /drag ratio, a measurement of the efficiency of a wing aerofoil section

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LDA - landing distance available.

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LED - light emitting diode

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LF - low-frequency radio waves with frequencies in the 30-300 kHz band.

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LITAS - low-intensity two-colour approach system.

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LLTV - low light level television.

LLZ - localizer ((USA).

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LOC - localiser. The azimuth guidance portion of an instrument landing system.

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locator - medium-frequency non-directional radio beacon used as an aid to establishing yourself on final approach during an instrument landing procedure..

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LOFT - Line-orientated flying training. Usually on large jet simulators to prepare newly-qualified commercial pilots for multi-crew airline operations

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LOM - Locator outer marker

lon(g) - longitude

Loran - low-frequency hyperbolic radio long-range navigation system which measures time difference between reception of synchronised signals transmitted from ground transmitters. Loran-C, operates in the 100-110 kHz frequency band with an operating range of 600-1,500 nm independent of line-of-sight, and is becoming very popular among GA aircraft operators in the USA.

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M
M or mag - magnetic

Mach number - ratio of true airspeed to the speed of sound. Mach 1 is the speed of sound at sea level, ISA, approximately 1,100 feet per second or 760 mph.

MAP - missed approach point. The point on a published ILS approach expressed in time or distance from the final approach fix, or as an altitude on the glideslope, at which the missed approach procedure must be initiated if the runway or approach lights are not clearly in sight.

marker beacons (mkrs) - part of an instrument landing system using 75 MHz transmitters emitting fan-shaped or elliptical signal patterns vertically upwards, defining specific points along the glideslope. The outer marker OM is situated at or near the glideslope intercept altitude of the ILS localiser, the middle marker (MM) defines a point on the glideslope at or near decision height (DH). Markers provide aural and visual indications on a cockpit marker beacon receiver.

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MATZ - military aerodrome traffic zone. An area of protected airspace surrounding certain military airfields which normally extends for a five nautical mile radius around the airfield and upwards from the surface to 3,000 feet above aerodrome level. A 'stub' projection protects the final approach path to the main runway outwards from the MATZ boundary, enclosing an area two nautical miles either side of the extended runway centreline and upwards from 1,000 feet above the surface to 3,000 feet above aerodrome elevation. Although recognition of a MATZ is not mandatory for civil aircraft, all MATZ aerodromes offer a penetration service to civil traffic during operational hours.

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Mayday - international radio distress call (from the French, m'aidez -- help me). It signifies imminent danger to life requiring immediate assistance.

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mb - millibar.

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MCC - Multi-crew co-operation

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MCU - management control unit

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MDA - minimum descent altitude. The lowest altitude, in feet amsl, to which descent is authorised on final approach during a non-precision instrument landing (i.e. where no glideslope guidance is given) without visual reference to the runway.

MDH - minimum descent height, agl.

MEDA - military emergency diversion airfield.

medevac - medical evacuation

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Met - meteorology, weather.

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METAR - coded aerodrome Met report. Also SPECI, special civil aviation weather report, and TAF, terminal aerodrome forecast of weather expected.

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MF - medium frequency. Radio waves with frequencies in the 300- 3,000 kHz range.

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MFA - military flying area

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MFD - multi-function display. An EFIS CRT offering selectable displays of weather radar, navigation maps, checklists and data other than primary flight information.

MH - magnetic heading

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MHz - Megahertz, the frequency of radio carrier waves measured in millions of cycles per second.

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minimums - weather condition requirements for a particular mode of flight (e.g. for VFR operation, IFR take-offs and landings).

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MLS - microwave landing system. A microwave-based instrument approach system intended to replace ILS in the 1990s and claimed to offer a number of advantages such as the ability to fly segmented and curved precision approaches.

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MLW - maximum landing weight. Weight of an aircraft above whivh fuel must be burned off or jettisoned before landing or there may be risk of structual damage

mm - millimetre's

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MMARS - Military Middle Airspace Radar Service, available to military and civil aircraft operating in UK airspace between FL100 and FL245.

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MOA - military operations area.

MoD - UK's Ministry of Defence

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mod - modification to an aircraft or equipment

mogas - car fuel, approved for use in some light aircraft subject to certain conditions.

MPA - man-powered aircraft

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mph - miles per hour

MPI - major periodic inspection

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MSA - minimum sector altitude or minimum safe altitude.

msl - mean sea level

MTBF - mean time between failures. Also MTTR, mean time to repair

MTMA - military terminal control area.

MTOW - maximum take-off weight. The maximum allowable weight, including fuel and payload, specified in an aircraft's Certificate of Airworthiness , sometime referred to (in USA especially) as maximum gross weight.

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MTWA - maximum total weight authorised.

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N  

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NAS - Naval Air Station (USA)

NATS - National Air Traffic Services. A division of the CAA providing UK air traffic control.

Nav - navigation.

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Navaid - navigation aid.

Nav/Com - navigation and communication.

NBAA - National Business Aircraft Association, USA.

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NDB - non-directional beacon. A medium-frequency navigational aid which transmits non-directional signals, superimposed with a Morse code identifier and received by an aircraft's ADF.

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NFT - navigation flight test

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nm - nautical mile(s).

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NOE - nap of earth. Low flying, usually by the military, using contour-flying techniques and terrain-masking to avoid being seen.

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NORDO - no radio (used on flight plan form).

NOSIG - no significant change, term used on Met reports.

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NOTAM - Notices to Airmen, issued by the CAA (and equivalent authorities elsewhere) to inform pilots of new or changed aeronautical facilities, services, procedures or hazards, temporary or permanent. Also SNOWTAM

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NOTAR - no tail rotor. A system patented by McDonnell Douglas for maintaining directional control of helicopters without use of an anti-torque tail rotor.

NPRM - Notice of Proposed Rule-Making (USA). Advance publication by the FAA of proposed changes or additions to Federal Air Regulations.

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NTSB - National Transportation Safety Board. U.S. equivalent of UK's AAIB.

nvg - night vision goggles.

NVQ - National Vocational Qualification. A Government-recognised qualification, the cost of training for which can be set against tax.

O  
OASC - Officers and Aircrew Selection Centre at RAF Cranwell

OAT - outside air temperature. The temperature of the air outside an aircraft measured by a probe with a cockpit gauge readout. OAT affects the measurement of indicated airspeed and its value is needed to calculate true airspeed. At high speeds kinetic heating demands correction to the indicated OAT for true outside air temperature.

OATS - Oxford Air Training School, a large commercial pilot training school at Oxford Airport, UK.

obst - obstruction.

OBS - omni-bearing selector, part of a VOR used to select the radial from a VOR.

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OCH - obstacle clearance height. The lowest height above the elevation of the runway threshold or above aerodrome elevation used to establish compliance with obstacle clearance criteria in an instrument approach. Also OCA, obstacle clearance altitude, and OCL, obstacle clearance limit.

OCU - Operational Conversion Unit.

OEI - One engine inoperative

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OEM - original equipment manufacturer.

OGE - Out of ground effect

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okta - a measurement of cloud cover. One okta means one-eighth of the sky is covered.

Omega - high accuracy, very-low frequency (VLF) long-range navigation system of the hyperbolic type, covering the entire earth down to the surface from eight ground-based transmitters. Used principally by airliners, military aircraft and intercontinental business aircraft.

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ops - Operations

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o/r - on request.

o/t - other times.

OTU - Operational Training Unit.

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P   

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P1 - Pilot-n-command

P2 - co-pilot

Pan - international radio call signalling urgency.

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PAPI - precision approach path indicator, a system of coloured lights installed at the approach end of a runway which provides visual guidance to the correct glidepath. A successor to VASI, below.

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PAR - precision approach radar. Primary radar equipment showing an air traffic controller the height, track and range of an aircraft on final approach, enabling him to guide it to a landing.

pax - passengers.

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PED - portable electronic devices.

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Permit to Fly - Authorisation granted to aircraft such as homebuilds, vintage aeroplanes, warbirds and some simple 'classic' light aircraft which are not required to meet the standards demanded for a full C of A, and are accordingly restricted in the kinds of operation for which they may be used. 

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PF - Pilot flying. The 'handling pilot' in multi-crew operation.

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PFA - Popular Flying Association, the UK homebuilt and antique aircraft organisation.

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PFD - primary flight display

PHG - powered hang-glider

PIC - pilot-in-command (also styled P1).

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PIG - Pilots Information Guide

pinch-hitter - U.S. term for safety-pilot, usually unlicensed but having sufficient training to be competent to land an aircraft in an emergency. Frequently the partner of the PIC

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PINS - Pipeline Inspection Notification System.

PIO - pilot-induced oscillation. An undulating flight path brought about by over-controlling.

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PLN - flight-plan.

PMS - performance management system.

PNF - Pilot not flying. The 'non-handling' pilot in multi-crew operation

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PNR - point of no return.

POB - (number of) persons on board. Also SOB, souls on board.

POC - proof-of-concept.

POH - pilot's operating handbook, an aircraft's 'owner's manual'.

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Pooley's - annually-published flight guide to United Kingdom and Ireland, named after its creator and publisher Bob Pooley.

PPG - powered paraglider.

PPL - Private Pilot's Licence.

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PPL(H) - Private Pilot's Licence for helicopters, 

PPL(SLMG) - Private Pilot's Licence for self-launched motor gliders.

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PPO - prior permission only. Certain airfields or events require advance notification (by telephone, for example) of your intended arrival. 

PROB - probability percentage, term used in Met reports.

procedure turn - manoeuvre which reverses the direction of an aircraft's flight during an instrument approach procedure to enable it to intercept the final approach course.

PPR -  prior permission required

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psi - pounds per square inch, a measurement of pressure.

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PTT - press-to-transmit (switch) on an aircraft's control wheel or stick enabling the pilot to make RT transmission 'hands on' via a headset microphone.

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Purple Airspace - special temporary airways created for flights by certain members of the royal family, notified by NOTAM.

Q  
QFI - Qualified Flying Instructor.  

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QHI - Qualified helicopter instructor.

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Quadrantal Rule - system of cruising altitudes used in UK uncontrolled airspace below FL250.

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Quarter-million - 1:250,000 scale ICAO aeronautical chart

Q-code - code system developed when air-to-ground communication was by wireless telegraphy, enabling many routine phrases and questions to be reduced to three letters. Now largely redundant, except these:

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QDM magnetic bearing to a direction-finding station. 
QDR magnetic bearing from the station. 
QFE atmospheric pressure at aerodrome elevation. With its sub-scale set to the aerodrome QFE an altimeter will indicate height above that airfield. 
QFU magnetic orientation of runway in use. 
QNE reading in feet on an altimeter set to 1013.2 millibars (standard pressure) when the aircraft is at aerodrome elevation. 
QNH altitude above mean sea level based on local station pressure. 
QSI change of frequency (use of QSY is officially discouraged in the UK but it is still in use in some other countries) 
QTE true line of position from a direction-finding station. 
QUJ true bearing 
R 
RAC - Rules of the Air and Air Traffic Services section of the AIP

rabbit lights - colloquialism for sequentially flashing lead-in runway approach lights.

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RAeS - Royal Aeronautical Society

RAF - Royal Air Force

ramp weight - maximum permissible weight of an aircraft, which exceeds maximum take-off weight by an allowance for fuel burned during engine-start and taxi.

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RAPID - change expected to take place in thirty minutes or less, term used in mer reports.

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RAS (1) - rectified airspeed. Indicated airspeed corrected for instrument position error.

RAS (2) - Radar Advisory Service. Provided outside regulated airspace to notify pilots of conflicting traffic and to advise suitable avoiding action. Under RAS controllers aim to achieve a minimum separation of five miles or 5,000 feet against unknown conflicting traffic

Rating - add-on qualification to a pilot's licence, e.g. Night Rating, Multi-engine Rating, Instrument Rating, Seaplane Rating etc. Individual Type Ratings are necessary to fly aircraft over 12,500 pounds MTWA.

RCL - runway centre-line.

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RBI - relative bearing indicator, displaying information from the ADF.

RDO - radio.

RIS - Radar Information Service. Provided to notify pilots of conflicting traffic outside regulated airspace, but offering no avoiding action.

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RMI - radio magnetic indicator. A navigation aid which combines DI, VOR and/or ADF display and will indicate bearings to stations, together with aircraft heading.

RMK - remark(s).

RMU - radio management unit.

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Rnav - area navigation. A system of radio navigation which permits direct point-to-point off-airways navigation by means of an on-board computer creating phantom VOR/DME transmitters termed waypoints.

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RON - remain over night (night-stop).

root - inner end of wing where it meets fuselage.

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rpm - revolutions per minute.

r/t or RT  - radio telephony. Voice communications, as opposed to WT, wireless telegraphy

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RTF - radio telephony.

RVR - runway visual range, a horizontal measurement of visibility along a runway.

rwy - runway.

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Rx - receiver.

S  
SACP - (CAA) Standing Advisory Committee on Pilot Licensing.

SAR - search-and-rescue. Also Sarsat, SAR satellite.

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SAS - stability augmentation system. An automatic flight control system employed in many helicopters and some fixed-wing aircraft to enhance their stability and handling qualities.

SATCO -  senior air traffic control officer

satcoms - satellite communications, now being introduced on intercontinental airliners and business jets for (non- operational) air-to-ground voice communications via ground relay stations.

SB - Service Bulletin. Advisory notices issued by aircraft, engine and equipment manufacturers alerting owners and engineers to faults or problems requiring preventitive or remedial maintenance or modification. Often termed 'mandatory', but do not have the legal force of Airworthiness Directives (which see).

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SBAC - Society of British Aerospace Companies. The UK aerospace manufacturers' trade association.

SDAU - Safety Data Analysis Unit of the CAA.

'second pilot' - unofficial term used to describe short (usually 8-10 hours) flying courses designed to enable non-pilot light aircraft passengers to take control and land in an emergency such as pilot incapacitation. Also standby or safety pilot and pinch-hitter (U.S.)

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Sectional - (U.S.) VFR navigation chart, equivalent to our 1:500,000 or 'half-million'.

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Semi-circular - system of cruising altitudes.

SELCAL - selective calling. A high-frequency system enabling air traffic control to alert a particular aircraft, by means of flashing light or aural signal in the cockpit, for receipt of a message without the crew having to maintain a listening watch. Used on long-haul over-ocean airline routes and by intercontinental bizjets.

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sfc - specific fuel consumption of an engine, expressed in pounds of fuel consumed for each unit of power (hp, shp, lb/st) produced. Also surface.

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short final - radio call made from aircraft calling later than final position, or on final approach from a shortened circuit, or at 2nm from threshold on a straight-in approach.

shp - shaft horsepower.

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SID - standard instrument departure. A standard IFR departure route enabling air traffic controllers to issue abbreviated clearances and thus speed the flow of traffic.

SIGMET - warning of severe weather conditions (active thunderstorms, hail, severe turbulence, icing etc.) issued my Met offices.

sl - sea level.

SLA - small light aircraft

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SLMG - self-launching motor glider

SMOH - since major overhaul. Term used in aircraft for sale advertisements where engine hours are quoted (see TBO). Also STOH, TTSN, TTAF/E

SMR - surface movement radar.

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SNOWTAM - a NOTAM concerning runway conditions in snow.

SOB - souls on board, the number of persons on board an aircraft. Also POB.

socked-in - A colloquialism referring to an airport closed to air traffic by bad weather, similarly clamped.

SOP - standard operating procedure.

specific range - measure of an aircraft's fuel efficiency, expressed as nautical miles flown per pound of fuel burned (nm/lb)

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SPL - Student Pilot's Licence. No longer issued in the UK, where a CAA medical certificate serves as an SPL.

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squawk - to transmit an assigned code via a transponder (see SSR below).

SR - sunrise.

SRG - Safety Regulation Group of the CAA

SRZ - Special Rules Zone. An area of protected airspace surrounding an airfield and extending from the surface upwards to a specific level which affords safety to air traffic movements in the vicinity of airfields whose traffic level does not warrant the establishment of a Control Zone. Also SRA, Special Rules Area. extending vertically and horizontally from a level above the surface, but not necessarily terminating at the same upper level as the SRZ.

SRA - Surveillance Radar Approach. Also Special Rules Area.

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SRE - Surveillance Radar Element of a GCA.

SS - sunset.

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SSB - single sideband. Reduction of bandwith by transmitting only one sideband and suppressing the other, and usually also the carrier wave.

SSR - secondary surveillance radar. A radar system comprising a ground-based transmitter/receiver which interrogates a compatible unit in the aircraft (see transponder), providing instant radar identification without having to manoeuvre. Assigned four-digit transponder codes are referred to as squawk codes.

STAR - Standard Terminal Arrival Route, for inbound IFR traffic.

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STC - Supplemental Type Certificate. U.S. system for post-type certification approval of aircraft modifications such as re- engining, STOL kits, etc, where the full certification process is not deemed necessary. Also used by manufacturers to certify (often greatly changed) new models of old types under so-called 'grandfather rights'.

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STOH - since top overhaul

STOL - short take-off and landing. Also VTOL,  V/STOL,

STOVL - short take-off, vertical landing.

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T
T - true. Also TH, true heading, and TT, true track.

TACAN - tactical air navigation system. An ultra-high frequency electronic navigation aid which provides suitably-equipped aircraft with a continuous indication of bearing and distance to the selected Tacan station. The distance element can be received by civilian DMF equipment, but otherwise Tacan is principally a military navaid.

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TAF - Terminal Area Forecast.

TAS - true airspeed. Rectified airspeed corrected for altitude and outside air temperature.

TBO - time between overhauls, an engine manufacturer's recommended overhaul interval in hours, a rough and not guaranteed guide to life expectancy of an aero-engine before it will need overhaul.

TCA - Terminal Control Area (USA).

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TCAS - traffic alert and collision avoidance system. U.S. developed radar-based airborne collision avoidance system operating independently of ground-based equipment. TCAS-I generates traffic advisories only, TCAS-II provides advisories and collision avoidance instructions in the vertical plane.

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TEMPO - temporarily, term used in Met reports.

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TET - turbine entry temperature.

TGT - turbine gas temperarture.

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THR or thld - threshold.

TMA - Terminal Control Area. An area of controlled airspace at the intersection of airways in the vicinity of control zones (CTRs) around major airports.

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TO - take-off (sometimes TKOF).

TODA - take-off distance available. Also TODR, take-off distance required, and TORA, take-off run available.

track - actual flight path of an aircraft over the ground.

transponder - airborne receiver/transmitter portion of the SSR system which receives the interrogation signal from the ground and automatically replies according to mode and code selected. Modes A and B are used for identification, using a four-digit number allocated by air traffic control. Mode C gives automatic altitude readout from an encoding altimeter.

transition altitude (TA) - altitude in the vicinity of an aerodrome at or below which the vertical position of an aircraft is controlled by reference to altitude, i.e. with the aerodrome QNH set on its altimeter. Above transition altitude QNE is set and flight levels used. Also transition level (TL) at which a descending aircraft changes from FL to QNH.

trend - Met forecast for the next two hours, added to some METARs.

TSO - Technical Standard Order. A standard established by the U.S. FAA for quality control in avionics, instruments and other airborne equipment. If it complies, equipment is said to be 'TSO'd' and is more expensive than similar non-TSO's equipment.

TTAF/E - total time airframe/engine,

TTSN - total time since new

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TVOR - terminal VOR. A low-powered VOR located at or near an airport and used as an approach aid.

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TWR - Tower (aerodrome control tower).

TWY - taxiway.

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Tx - transmitter.

tyro - Can be used as an r/t call prefix by inexperienced pilots in distress or urgency situations to ensure they are not passed instructions beyond their capabilities.

U 
UAS - University Air Squadron.

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UDF - UHF direction finding.

UFN - until further notice.

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UHF - ultra-high frequency. Radio frequencies in the 300-3,000 MHz band.

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UHMRA - Upper Heyford Mandatory Radio Area.

UIR - Upper Information Region, covering the same geographic areas as a FIR, but extending vertically upwards from 24,500 feet, within which certain additional operational rules apply. Also UIS, Upper Information Service.

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Unicom - privately-operated advisory A/G radio service at uncontrolled airfields (USA). UNL - unlimited

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u/s - unserviceable (i.e not working) when applied to an aircraft or its equipment.

UTC - Co-ordinated Universal Time, formerly Greenwich Mean Time (see also Zulu).

V  
V-speeds - designations for certain velocities relating to aircraft operation, thus:

V1 decision speed, up to which it should be possible to abort a take-off and stop safely within the remaining runway length. After reaching V1 the take-off must be continued. 
Va design manoeuvring speed. The speed below which abrupt and extreme control movements are possible (though not advised) without exceeding the airframe's limiting load factors. 
Vfe maximum flap extension speed (top of white arc on ASI). 
Vle maximum landing gear extended speed 
Vmca minimum control speed (air). The minimum speed at which control of a twin-engined aircraft can be maintained after failure of one engine. 
Vmo maximum operating speed. Also Mmo, Mach limit maximum operating speed. 
Vne never-exceed speed, 'redline speed' denoted by a red radial on an ASI. 
Vno normal operating speed. The maximum structural cruising speed allowable for normal operating conditions (top of green arc on ASI). 
Vr rotation speed, at which to raise the nose for take-off. 
Vso stalling speed at MTWA, in landing configuration with flaps and landing gear down, at sea level, ISA conditions (bottom of white arc on ASI). 
Vx best angle of climb speed on all engines. 
Vxse best engine-out angle of climb speed. 
Vy best rate of climb speed on all engines. 
Vyse best engine-out rate of climb speed, 'blueline speed' (blue radial on ASIs of light twins) 
VAL - visual approach and landing chart.

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var - variation (magnetic)

VASI - visual approach slope indicator 

VASIS - visual approach slope indicator system. A coloured light system providing visual guidance to the glidepath of a runway.

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VDF - very-high frequency direction-finding, whereby an aircraft's bearing from a ground receiving station may be determined from its RT transmissions.

vdu - visual display unit.

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VFR - Visual Flight Rules. Prescribed for the operation of aircraft in visual meteorological conditions (VMC).VMC is generally defined as five miles visibility or more and 1,000 feet vertical and one nautical mile horizontal clearance from cloud, but variations apply to aircraft operating below 3,000 feet amsl. Special VFR (SVFR) clearances are granted at the discretion of ATC for VFR flight through some controlled airspace where IFR usually apply. Also CVFR, Controlled VFR Flight.

VGS - Volunteer Gliding School (RAF Air Cadets)

VHF - very high frequency. Radio frequencies in the 30-300 MHz band, used for most civil air-to-ground communication.

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vis - visibility.

VLA - very light aircraft

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VLF - very low frequency. Radio frequencies in the 3-30 kHz band.

VLF/Omega - worldwide system of long-range navigation using VLF radio transmission.

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VMC - Visual Meterorological Conditions. See VFR, above.

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Vnav - vertical navigation.

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Vne - never exceed airspeed

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Volmet - continuous recorded broadcasts of weather conditions at selected airfields.

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VOR - very high frequency omnidirectional range. A radio navigation aid operating in the 108-118 MHz band. A VOR ground station transmits a two-phase directional signal through 360ø. the aircraft's VOR receiver enables a pilot to identify his radial or bearing from/to the ground station. VOR is the most commonly used radio navigation aid in private flying. Increased accuracy is available in Doppler VORs (DVOR) which have replaced some VOR is the UK system. Also VORTAC, combined VOR and TACAN, and VOT, VOR test facility.

VP - variable-pitch (propeller), whose blade angle can be altered in flight either automatically or manually.

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Vr - Rotation speed

VRP - visual reference point. (In the UK) Landmarks used for position reporting by aircraft operating VFR.

VSI - vertical speed indicator. One of the primary flight instruments showing rate of climb or descent. Also IVSI, instantaneous VSI.

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V/STOL -  vertical/short take-off and landing

VTOL - vertical take-off and landing.

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VTR - vocational training relief. Tax releif granted by the Inland Revenue against the cost of certain commercial pilot training courses.

W 
wake turbulence - wingtip vortices generated behind a wing producing lift. Behind a large heavy aircraft they can be powerful enough to roll or even break up a smaller aircraft.

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WAT - weight-and-temperature.

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w.e.f. - with effect from. Also w.i.e., with immediate effect.

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wet - when refering to aircraft hire charges means 'fuel included'

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wind shear - localised change in wind speed and/or direction over a short distance, resulting in a tearing or shearing effect, usually at low altitude, that can cause a sudden loss of airspeed with occasionally disastrous results if encountered when taking-off or landing.

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WIP - work in progress.

WP - waypoint.

wt - weight

Wx - weather.

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WX NIL - no significant weather, term used in Met reports.

X 
XC - cross-country

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xmsn - transmission.

xpdr - transponder.

Y     
Z     
zero-fuel weight - maximum permissible weight of an aircraft beyond which an additional load must be in the form of fuel (i.e. max take-off weight less total usable fuel in applicable aircraft, which are so limited because of the wing-bending moments associated with near-empty wing fuel tanks).

zero-timed - overhauling an aero-engine to 'service limits' (not the same 'good as new' or factory remanufactured).

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Zulu or Z - used worldwide for times of flight operations, formerly Greenwich Mean Time, now Co-ordinated Universal Time (UTC).

1179

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1179 - flight test to add a new aircraft type to a professional licence, actually the reference number of the test form used