航空缩略语（M-gt；Z）

　　Mor mag-magnetic

　　Mach number-ratio of true airspeed to the speed of sound。Mach1is the speed of sound at sea level，ISA，approximately1，100feet per second or760mph。

　　MAP-missed approach point。The point on a published ILSapproach 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 using75MHz transmitters emitting fan-shaped or elliptical signal patterns vertically upwards，defining specific points along the glideslope。The outer marker OMis situated at or near the glideslope intercept altitude of the ILSlocaliser，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。

　　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 to3，000feet above aerodrome level。A‘stub’projection protects the final approach path to the main runway outwards from the MATZboundary，enclosing an area two nautical miles either side of the extended runway centreline and upwards from1，000feet above the surface to3，000feet above aerodrome elevation。Although recognition of a MATZis not mandatory for civil aircraft，all MATZaerodromes offer a penetration service to civil traffic during operational hours。

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

　　mb-millibar。

　　MCC-Multi-crew co-operation

　　MCU-management control unit

　　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

　　Met-meteorology，weather。

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

　　MF-medium frequency。Radio waves with frequencies in the300-3，000kHz range。

　　MFA-military flying area

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

　　MH-magnetic heading

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

　　minimums-weather condition requirements for a particular mode of flight（e.g.for VFRoperation，IFRtake-offs and landings）。

　　MLS-microwave landing system。Amicrowave-based instrument approach system intended to replace ILSin the1990s and claimed to offer a number of advantages such as the ability to fly segmented and curved precision approaches。

　　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

　　MMARS-Military Middle Airspace Radar Service，available to military and civil aircraft operating in UKairspace between FL100and FL245。

　　MOA-military operations area。

　　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

　　mph-miles per hour

　　MPI-major periodic inspection

　　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 USAespecially）as maximum gross weight。

　　MTWA-maximum total weight authorised。

　　NAS-Naval Air Station（USA）

　　NATS-National Air Traffic Services。Adivision of the CAAproviding UKair traffic control。

　　Nav-navigation。

　　Navaid-navigation aid。

　　Nav/Com-navigation and communication。

　　NBAA-National Business Aircraft Association，USA。

　　NDB-non-directional beacon。Amedium-frequency navigational aid which transmits non-directional signals，superimposed with a Morse code identifier and received by an aircraft‘s ADF。

　　NFT-navigation flight test

　　nm-nautical mile（s）。

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

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

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

　　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。Asystem 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 FAAof proposed changes or additions to Federal Air Regulations。

　　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。

　　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。OATaffects the measurement of indicated airspeed and its value is needed to calculate true airspeed。At high speeds kinetic heating demands correction to the indicated OATfor 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 VORused to select the radial from a VOR。

　　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

　　OEM-original equipment manufacturer。

　　OGE-Out of ground effect

　　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。

　　ops-Operations

　　o/r-on request。

　　o/t-other times。

　　OTU-Operational Training Unit。

　　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。Asuccessor to VASI，below。

　　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。

　　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 Cof A，and are accordingly restricted in the kinds of operation for which they may be used。

　　PF-Pilot flying。The‘handling pilot’in multi-crew operation。

　　PFA-Popular Flying Association，the UKhomebuilt and antique aircraft organisation。

　　PFD-primary flight display

　　PHG-powered hang-glider

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

　　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

　　PINS-Pipeline Inspection Notification System。

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

　　PLN-flight-plan。

　　PMS-performance management system。

　　PNF-Pilot not flying。The‘non-handling’pilot in multi-crew operation

　　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‘。

　　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。

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

　　PPL（SLMG）-Private Pilot‘s Licence for self-launched motor gliders。

　　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

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

　　PTT-press-to-transmit（switch）on an aircraft‘s control wheel or stick enabling the pilot to make RTtransmission’hands on‘via a headset microphone。

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

　　QFI-Qualified Flying Instructor。

　　QHI-Qualified helicopter instructor。

　　Quadrantal Rule-system of cruising altitudes used in UKuncontrolled airspace below FL250。

　　Quarter-million-1:250，000scale ICAOaeronautical 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：

　　QDMmagnetic bearing to a direction-finding station。

　　QDRmagnetic bearing from the station。

　　QFEatmospheric pressure at aerodrome elevation。With its sub-scale set to the aerodrome QFEan altimeter will indicate height above that airfield。

　　QFUmagnetic orientation of runway in use。

　　QNEreading in feet on an altimeter set to1013.2millibars（standard pressure）when the aircraft is at aerodrome elevation。

　　QNHaltitude above mean sea level based on local station pressure。

　　QSIchange of frequency（use of QSYis officially discouraged in the UKbut it is still in use in some other countries）

　　QTEtrue line of position from a direction-finding station。

　　QUJtrue bearing

　　RAC-Rules of the Air and Air Traffic Services section of the AIP

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

　　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。

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

　　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 RAScontrollers aim to achieve a minimum separation of five miles or5，000feet 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 over12，500pounds MTWA。

　　RCL-runway centre-line。

　　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。

　　RMI-radio magnetic indicator。Anavigation aid which combines DI，VORand/or ADFdisplay and will indicate bearings to stations，together with aircraft heading。

　　RMK-remark（s）。

　　RMU-radio management unit。

　　Rnav-area navigation。Asystem of radio navigation which permits direct point-to-point off-airways navigation by means of an on-board computer creating phantom VOR/DMEtransmitters termed waypoints。

　　RON-remain over night（night-stop）。

　　root-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。

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

　　rwy-runway。

　　Rx-receiver。

　　SACP-（CAA）Standing Advisory Committee on Pilot Licensing。

　　SAR-search-and-rescue。Also Sarsat，SARsatellite。

　　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）。

　　SBAC-Society of British Aerospace Companies。The UKaerospace manufacturers‘trade association。

　　SDAU-Safety Data Analysis Unit of the CAA。

　　’second pilot‘-unofficial term used to describe short（usually8-10hours）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。）VFRnavigation chart，equivalent to our1:500，000or’half-million‘。

　　Semi-circular-system of cruising altitudes。

　　SELCAL-selective calling。Ahigh-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。

　　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。

　　short final-radio call made from aircraft calling later than final position，or on final approach from a shortened circuit，or at2nm from threshold on a straight-in approach。

　　shp-shaft horsepower。

　　SID-standard instrument departure。Astandard IFRdeparture 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

　　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。

　　SNOWTAM-a NOTAMconcerning runway conditions in snow。

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

　　socked-in-Acolloquialism 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）

　　SPL-Student Pilot‘s Licence。No longer issued in the UK，where a CAAmedical certificate serves as an SPL。

　　squawk-to transmit an assigned code via a transponder（see SSRbelow）。

　　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。

　　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。

　　SSR-secondary surveillance radar。Aradar 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 IFRtraffic。

　　STC-Supplemental Type Certificate。U。S。system for post-type certification approval of aircraft modifications such as re-engining，STOLkits，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‘。

　　STOH-since top overhaul

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

　　STOVL-short take-off，vertical landing。

　　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 DMFequipment，but otherwise Tacan is principally a military navaid。

　　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）。

　　TCAS-traffic alert and collision avoidance system。U。S。developed radar-based airborne collision avoidance system operating independently of ground-based equipment。TCAS-Igenerates traffic advisories only，TCAS-IIprovides advisories and collision avoidance instructions in the vertical plane。

　　TEMPO-temporarily，term used in Met reports。

　　TET-turbine entry temperature。

　　TGT-turbine gas temperarture。

　　THRor 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。

　　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 SSRsystem which receives the interrogation signal from the ground and automatically replies according to mode and code selected。Modes Aand Bare used for identification，using a four-digit number allocated by air traffic control。Mode Cgives 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 QNHset on its altimeter。Above transition altitude QNEis set and flight levels used。Also transition level（TL）at which a descending aircraft changes from FLto QNH。

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

　　TSO-Technical Standard Order。Astandard established by the U。S。FAAfor 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

　　TVOR-terminal VOR。Alow-powered VORlocated at or near an airport and used as an approach aid。

　　TWR-Tower（aerodrome control tower）。

　　TWY-taxiway。

　　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。

　　UAS-University Air Squadron。

　　UDF-UHFdirection finding。

　　UFN-until further notice。

　　UHF-ultra-high frequency。Radio frequencies in the300-3，000MHz band。

　　UHMRA-Upper Heyford Mandatory Radio Area。

　　UIR-Upper Information Region，covering the same geographic areas as a FIR，but extending vertically upwards from24，500feet，within which certain additional operational rules apply。Also UIS，Upper Information Service。

　　Unicom-privately-operated advisory A/Gradio service at uncontrolled airfields（USA）。UNL-unlimited

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

　　V1decision speed，up to which it should be possible to abort a take-off and stop safely within the remaining runway length。After reaching V1the 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，ISAconditions（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。

　　var-variation（magnetic）

　　VASI-visual approach slope indicator

　　VASIS-visual approach slope indicator system。Acoloured 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 RTtransmissions。

　　vdu-visual display unit。

　　VFR-Visual Flight Rules。Prescribed for the operation of aircraft in visual meteorological conditions（VMC）。VMCis generally defined as five miles visibility or more and1，000feet vertical and one nautical mile horizontal clearance from cloud，but variations apply to aircraft operating below3，000feet amsl。Special VFR（SVFR）clearances are granted at the discretion of ATCfor VFRflight through some controlled airspace where IFRusually apply。Also CVFR，Controlled VFR Flight。

　　VGS-Volunteer Gliding School（RAF Air Cadets）

　　VHF-very high frequency。Radio frequencies in the30-300MHz band，used for most civil air-to-ground communication。

　　vis-visibility。

　　VLA-very light aircraft

　　VLF-very low frequency。Radio frequencies in the3-30kHz band。

　　VLF/Omega-worldwide system of long-range navigation using VLFradio transmission。

　　VMC-Visual Meterorological Conditions。See VFR，above。

　　Vnav-vertical navigation。

　　Vne-never exceed airspeed

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

　　VOR-very high frequency omnidirectional range。Aradio navigation aid operating in the108-118MHz band。A VORground station transmits a two-phase directional signal through360ø。the aircraft‘s VORreceiver enables a pilot to identify his radial or bearing from/to the ground station。VORis the most commonly used radio navigation aid in private flying。Increased accuracy is available in Doppler VORs（DVOR）which have replaced some VORis the UKsystem。Also VORTAC，combined VORand TACAN，and VOT，VORtest facility。

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

　　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。

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

　　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。

　　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。

　　WAT-weight-and-temperature。

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

　　wet-when refering to aircraft hire charges means’fuel included‘

　　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。

　　WIP-work in progress。

　　WP-waypoint。

　　wt-weight

　　Wx-weather。

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

　　XC-cross-country

　　xmsn-transmission。

　　xpdr-transponder。

　　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 newor factory remanufactured）。

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

　　1179

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