The Cambridge Aerospace Dictionary Episode 2 doc

2 Advanced Space Transportation Program (NASA). ASTR Attack store; usually (and very confusingly) means which type of AAM is selected, not air/ground weapon. Astra, ASTRA 1 Applications of Space Technology to Requirements of Civil Aviation (ICAO panel); 1986 renamed Application of Space Techniques Relating To Aviation, later still Space replaced by Satellite. 2 Air staff training programme. 3 Association in Scotland to Research into Astronautics. 4 Advanced systems training aircraft (ETPS). 5 Attitude steering turn-rate azimuth. Astral Air-surveillance and targeting radar L-band. Astras Airport surface-traffic awareness system (ICAO), confusion with ASTA[2]. Astrid Airborne system for target recognition, identifi- cation and designation. astrionics Space electronics. Astro 1 Air support to regular operations (police heli- copters). 2 Autonomous space transport robotic operations, or -and robotic orbiter (Darpa). astrobiology Science of possible life on planets other than Earth, or elsewhere in space (note, in R means ‘space medicine’). astrocompass Non-magnetic instrument, gives direction of true North relative to celestial body which must emit light and be of known direction (see astronavigation). astrodome Optically transparent dome in roof of large aircraft 1935–50 through which navigator could take astro fixes using sextant. astro fix Fix obtained by sighting two or more stars of known direction using sextant or astrocompass. astrogation Navigation in space, suggest colloq. astro-inertial Navigation by means of inertial system updated or corrected by astro fixes. astronaut One who navigates in space; ie who travels in space. Specif., one selected for space flight by NASA. astronautics Science of study, design, construction and operation of spacecraft. astronavigation 1 Navigation of aircraft or spacecraft by measuring declination, right ascension and/or other angular positions of stars and other celestial bodies whose location on celestial sphere is known. 2 Navigation of spacecraft by any means (usage ambiguous). astronics Astrionics. astronomical twilight Period between day and night when Sun’s centre between 12° and 18° below sea-level horizon (see civil twilight, nautical twilight). Astronomical Unit, AU, A.U. Unit of linear distance based on mean distance between Earth and Sun; accepted value was 149,598,500 km, but IAU definition is now 1,496×10 11 m. astronomy Science of celestial bodies other than Earth. Not included in this definition are celestial phenomena, such as polarisation of stellar light and other measures concerned more with radiation than with ‘bodies’. Thus, subdivision radar *, X-ray *, IR *, UV * etc. astrophysics Physics of observable universe, esp. states of matter and energy generation and transfer. astroseismology Study of earthquakes on bodies other than Earth. astro-tracker Automatic sextant capable of searching celestial sphere for particular luminous body, identifying it and determining orientation in terms useful for naviga- tion, and of repeating sequence with same and at least one other celestial body. Corrects and updates INS in long- range aircraft. ASTS Association Suisse pour les Techniques Spatiales (Switz). ASU 1 Aeromedical staging unit. 2 Altitude (or, confusingly, attitude) sensing unit. 3 Approval for service use. 4 Aircraft storage unit (UK). 5 Aircraft starting unit. 6 Acoustic simulation unit. 7 Avionics switching unit. Asupt Advanced simulator for undergraduate pilot training. ASUW, ASuW Anti-surface [or anti-surface-unit] warfare aircraft category (USN). ASV 1 Air-to-surface vessel. WW2 airborne search radar. Incorrectly rendered as anti-surface vessel. See ASVW. 2 Aerial swimming vehicle. ASVEH Air-surveillance vehicle. ASVS Airborne separation video system. ASVW Anti-surface vessel warfare, today’s term. ASW 1 Anti-submarine warfare [AC adds analysis center, AS area system, DS data system, SOW stand-off weapon and T trainer]. 2 Aft-swept wing. 3 Confusingly, also used in US for anti-ship warfare, and in UK (WW2) for air/sea warfare. 4 Acquisition scan window (UAV). ASWAC Airborne surveillance, warning and control [S adds system] (India). ASWDU Air/Sea Warfare Development Unit (RAF/RN). ASWE Admiralty Surface Weapons Establishment (Portsdown, UK). ASWOC ASW [1] operations centre. ASWT Air-to-surface weapons technology. ASXV Air-launched expendable sound velocimeter. asymmetric flight Flight by aerodyne in sustained grossly asymmetric condition of lift, weight, thrust or drag, esp. flight by multi-engined aircraft in which at least one engine at substantial distance from axis of symmetry is inoperative. asymmetric loading Flight by aircraft, esp. aerodyne, in which c.g. is located at substantial distance from vertical line through centre of lift with aircraft in level attitude and trimmed for normal horizontal flight (eg strike aircraft unable to release one of two heavy stores carried on outer- wing pylons). asymmetric warfare Conflict between a high-tech nation and a primitive one. asymptote Limiting position of tangent to curve, where lines meet at infinity. Thus, asymptotic, where slope of plotted curve becomes parallel to either x or y axis. asynchronous Not synchronised, not in frequency or phase. asynchronous computer Electronic computer, usually digital, in which operations do not proceed according to timing clock but are signalled to start by completion of preceding operation. ASTR asynchronous computer 61 ASZ Air surface zone (NATO, USAF). AT 1 Advanced trainer (USAAF category, 1924–48). 2 Anti-tank. 3 Autogenic training. 4 Autothrottle [also A/T]. 5 Air transmit. 6 Armament trainer (F-22). 7 Air transport (role of tanker). 8 All traffic. 9 Advanced targeting. AT 3 See ATTT. ATA 1 Air Transport Auxiliary, UK ferry organization 1940–45; also the Association, 1946–. 2 Air Transport Association of America (scheduled carriers). 3 Actual time of arrival. 4 Advanced tactical aircraft. 5 Air Transport Association (UK). 6 Automatic target-acquisition. 7 Aero Testing Alliance (F, G, Neth.). 8 Aviation Training Association (UK). 9 Airport traffic area. 10 Airline-tariff analysis. 11 Advanced testbed[s] for avionics. ata Atmosphere[s] pressure; 1 ata [atm in UK]= 101.325 kPA = 14.6959 lb/in 2 . ATAAC Anti-torpedo air-launched countermeasure[s]. ATAAS Advanced terminal area approach spacing. ATAB Air Transport Allocations Board, joint agency in theatre of operations which assigns priorities to loads. ATAC 1 Air Transport Association of Canada. 2 Applied-technology advanced computer (airborne EW). 3 Air-transportable acoustic communication[s], expandable buoy. ATACC Advanced tactical air command center (USMC). ATACMS Army tactical missile system[s] (USA). Ataco Air Tactical Control Officer. ATAF 1 Allied Tactical Air Force (NATO). 2 Association Internationale des Transporteurs Aériens (acronym from previous title). ATAFCS Airborne target acquisition and fire-control system. ATAG Air Transport Action Group, coalition pressing for better infrastructure. Atags Advanced-technology anti-g suit (USAF). ATAL, Atal 1 Automatic test application language. 2 Appareillage de TV sur aéronef léger (F). ATALS Army Transportation and Logistics School (USA). ATAM Air-to-air Mistral. ATAOS Autonomous tactical attack and observation system. ATAP Advanced tactical-, or target-, attack penetrator. ATAR 1 Air-to-air recognition (device). 2 Air-to-air recovery. 3 Advanced threat-alert and response; CE adds critical experiment (USAF). 4 Association des Transporteurs Aériens Régionaux (F). Atares Air-transport and air-refuelling exchange of services (European Air Group). Atars 1 Automatic traffic-advisory and resolution service (UK). 2 Advanced tactical air-reconnaissance system. ATAS, Atas 1 Air Traffic Advisory Service, provides separation between known aircraft in IFR on certain routes (UK DTI). 2 Advanced target-acquisition sensor. 3 Air-to-air Stinger. 4 Automated talking advisory system (FAA). ATATS Automatic target-acquisition and tracking- system. Ataws Advanced tactical air-warfare system. ATB 1 Advanced-technology bomber. 2 Air-Transport Bureau (ICAO). 3 Aerospace Technology Board. 4 Automated ticket and boarding pass. 5 Advanced-technology blade (HP turbine). ATBM Anti-tactical, or anti-theater, ballistic missile. ATC 1 Air traffic control; C adds centre. 2 Air Training Corps (UK, replaced ADCC in 1941). 3 Air Training Command (USAF, from 15 April 1946). 4 Air Transport Command, formed from Air Ferrying Command 1 July 1942, became MATS. 5 Approved Type Certificate, first issued (by DoC) in 1927. 6 Advanced-technology component (DoD). 7 Aerospace Technical Council (AIAA). 8 Air transport conference (travel agencies). 9 Automatic [usually EW] threat-countering. 10 After top centre. 11 Acoustic-torpedo countermeasures. 12 Automatic tuning control. 13 Astronomy Technology Centre (Edinburgh, UK). 14 Airport traffic control (US DoC 1938). ATCA 1 Air Traffic Control Association (US, organ- ised 1955). 2 Air Traffic Conference of America. 3 Allied Tactical Communications Agency (NATO). 4 ATC Assistant (UK). 5 Advanced tanker/cargo aircraft (USAF). ATCAC ATC Advisory Committee (US Congress). Atcap 1 ATC Automation Panel (ICAO). 2 Army Telecommunications Automation Program (USA). Atcare ATC analysis and recording environment. Atcas 1 ATC administration system. 2 ATC automation system. ATCC ATC centre/center (UK/US). ATC clearance Authorization by ATC for purpose of preventing collision between known aircraft for aircraft to proceed under specified conditions in controlled airspace (FAA). ATCCC, ATC3 ATC Command Center (FAA). ATCCTS 1 ATC communications training system. 2 ATC control-tower simulator. ATCE Air training centre of excellence. ATCEU ATC Evaluation Unit (Hurn, UK). ATCGS ATC ground segment [of satellite link]. ATCI ATC investigation of airprox. ATCMFT ATC multifunction trainer. Atco, ATCO 1 ATC officer. 2 Air-taxi and commercial operator. Atcom Aviation and Troop Command (USA). ASZ Atcom 62 ATCOMS, Atcoms ATC operations, or and opera- tional, management system[s]. ATCPS ATC procedures simulator. ATCPT ATC procedural trainer. ATCR 1 Air Training Command Regulation[s] (USAF). 2 ATC room[s]. ATCRBS ATC radar-beacon system (FAA). ATCRS ATC radar simulator. ATCRU ATC radar unit (UK). ATCS 1 ATC Service (UK), or simulator. 2 Active thermal-control subsystem. 3 Automated tower control system. ATCSCC ATC System (originally Services) Command Center (FAA, Herndon, VA). ATCSS ATC signalling system (air/ground datalink tested 1958 as alternative to voice). ATCT ATC (14) tower; S adds simulator. ATD 1 Actual time of departure. 2 Airline-, or aviation-, transmitted disease. 3 [translated] Aviation technical division (USSR, R). 4 Automatic threat detection; S adds system. 5 Applied Technology Directorate (USA). 6 Along-track distance. ATDA Augmented target docking adaptor. ATDC Automatic, or assisted, target detection and classification. ATDL Army tactical, or air-transport, datalink (USA). ATDMA Advanced time-division multiple access. ATDS 1 Airborne tactical data system. 2 Air-turbine drive system. ATDU Air Torpedo Development Unit (RAF Gosport 1940–46). ATE 1 Automatic test equipment. 2 Aircraft test and evaluation (UK). 3 Actual time en-route. 4 Advanced technology and engineering (also AT&E). ATEC 1 Aviation Technician Education Council (US). 2 Automatic test-equipment complex. Atecma, ATECMA Agrupación Técnica Española de Constructores de Material Aeroespacial (Spain). Ategg, ATEGG Advanced turbine engine gas- generator. Atems, ATEMS Advanced threat-emitter simulator. Atepsa Asociación Técnicos y Empleados de Protección e Securidad a la Aeronavegación (Argentina). ATER Advanced triple ejector rack. ATES Aircraft Test and Evaluation Sector (Qinetic/DRA, Boscombe Down). ATESS 1 Aerospace and telecommunications engineer- ing support services. 2 Advanced tactics and engagement simulation subsystem. ATF 1 Advanced tactical fighter. 2 Aviation turbine fuel. 3 Actual time of fall. 4 Amphibious task force. 5 Adaptive terrain-following. 6 Altitude test facility. 7 Air traffic flow. 8 Aerodrome, or airport, traffic frequency. 9 Air-transport force. Atfero Atlantic Ferry Organisation (UK, 1940–42). Atflir, Atfir, ATFLIR, ATFIR Advanced targeting forward-looking IR. ATFM Air traffic flow management; U adds unit. ATFPS Air taffic flow planning system. ATFS Authentic tactical flight simulator, or simulation. ATG 1 Amphibious task group. 2 Air-traffic generator. ATGS Air Tactical Group Supervisor, an experienced firefighter who provides aerial C 2 and also feeds informa- tion to the IC(8). ATGW Anti-tank guided weapon. ATH 1 Autonomous terminal homing. 2 Air-transportable hospital. 3 Automatic target handoff. athodyd Aero-thermodynamic duct, ie ramjet. Athos Airport tower harmonised controller system (Euret). A/THR Autothrottle mode. ATHS Airborne, or automatic, target handover, or handoff, system. ATI Air, or airline, transport instrument [standard panel sizes]. ATIF 1 Aeronautical telecommunications network trials infrastructure (ICAO). 2 All-source track and identification fusion. ATIG Air Technical Intelligence Group, of FEAF (1945–6). Atigs Advanced tactical inertial guidance system. ATILO Air technical-intelligence liaison officer. ATIMS Airborne target-information management system. ATIMU Advanced tactical inertial-measurement unit. ATIR Air-traffic incident report. ATIRCM Advanced threat, or theatre, IR countermea- sures. ATIS 1 Automatic, or automated, terminal informa- tion service (ICAO, FAA); continuous broadcast of recorded non-control information in selected high- activity terminal areas (to improve controller effectiveness, and relieve congestion by automating repetitive transmission of routine information. 2 Airfield-terminal information system. 3 Air-traffic information service, or server, or system. ATISD Air Training Information Systems Division (Randolph AFB). ATITA Air Transport Industry Training Association (UK). ATITB Aviation and Travel Industry Training Board (NZ). ATK Aviation turbine kerosene. ATKHB Attack Helicopter Battalion (USA). ATk 1 Available tonne-kilometres. 2 Anti-tank. ATL 1 Airborne, or advanced, tactical laser. 2 Auto-trim loop. 3 Acquisition, technology and logistics (DoD). ATLA Air Transport Licensing Authority (Hong Kong, formerly). Atlantic Airborne targeting low-altitude navigation thermal imaging and cueing. Atlas 1 Abbreviated test language for avionics systems. 2 Advanced tactical low arresting system (overrun barrier). ATCOMS, Atcoms Atlas 63 3 Advanced tactical light arresting system (Aerazur cable/drum). 4 Advanced-technology ladar system. 5 Airborne topography and land-use assessment system. 6 Azimuth target-intelligence and acquisition system (Israel). 7 Antenna-testing laboratory automated system (NAS Patuxent). 8 Aircraft total lightning advisory system. ATLB Air Transport Licensing Board (UK). Atlis Automatic tracking laser illumination system. ATLND Automatic takeoff and landing (UAV). ATM 1 Air-turbine motor. 2 Air transport movement. 3 Air tasking [previously base] message, request for a particular combat mission to be flown (RAF). 4 Anti-tactical missile. 5 Anti-tank missile, or mine, or munition. 6 Asynchronous transfer, or transmission, mode. 7 Airspace, or air, traffic management [C adds centre, MG management group]. atm Atmospheres pressure (UK usage, see ata). ATMA Association Technique Maritime et Aéronautique (F). ATMG Arms Transfer Management Group (US DoD). Atmos Ammunition, toxic material open space. atmosphere 1 Gaseous envelope surrounding Earth, subdivided into layers (see atmospheric regions, model atmosphere). For composition see Air. 2 Gaseous or vaporous envelope surrounding other planets and celestial bodies. 3 Theoretical model atmosphere providing standard basis for performance and other calculation. 4 Any of group of units of pressure all approximately equal to pressure of atmosphere on Earth at sea level. Most important is Standard * (abb. ata on European continent, atm in UK) equal to 101,325 Nm -2 = 101,325 Pa = 1,013.25 mb = 1.01325 bars or hectopièze = 14.6959 lbf in -2 = 761.848 mm (29.994 in) Hg at 16.6°C. Second is Metric * (also ata) equal to 0.98642 Standard * and defined as 0.981117 bars (981.117 mb, ie acceleration due to 1 g) or 14.223 lbf in -2 . Third is Technical * (at), usually identical with Metric. Fourth is bar (b), 1000 mb = 750.07 mm Hg = 14.5038 lbf in -2 (see pressure). atmospheric absorption Absorption of EM radiation due to ionisation in atmosphere. Apparent loss of signal or beam power may be much greater, as result of diffrac- tion and dispersion by vapour and particular matter. atmospheric boundary layer Generally defined as Earth’s surface up to 5,000 ft or 1.5 km. atmospheric braking Use of air drag, esp. of upper atmosphere on re-entering spacecraft or RV, converting very high kinetic energy into heat. atmospheric circulation Gross quasi-permanent wind system of Earth, based on bands between parallels of latitude. atmospheric constituents See air. atmospheric diffraction Of importance chiefly with sound waves, which can be substantially changed in direc- tion and intensity distribution by changes in air velocity and density. Effect with most EM radiation is small. atmospheric duct Almost horizontal layer or channel in troposphere apparently defined by values of refractive index within which EM radiation, esp. in microwave region, is propagated with abnormal efficiency over abnormally great distances. atmospheric electric field Intensity of electrostatic field of Earth varies enormously, but on fine day may be about 100 V m –1 at SL falling to around 5 V m –1 at 10 km height. Air/Earth current continuously degrades ***, believed that thunderstorms reinforce it. atmospheric entry Re-entry, or entry of extraterrestrial bodies such as meteors. atmospheric filtering Use of upper zones of ionosphere and mesosphere to filter out ICBM decoys from true warheads, it being supposed that latter will have higher density, better thermal protection and increasingly divergent trajectories, while decoys decelerate more violently, fall behind and burn up. atmospheric pressure See atmosphere (4), atmospheric regions. atmospheric refraction Bending of EM radiation as it passes through different layers of atmosphere, esp. obliquely. Affects radio and radar, esp. when direction- ally beamed; visibly manifest in air over, say, hot roadway in sunshine when objects seen through this air ‘shimmer’; in astronavigation ** makes apparent altitude of celestial bodies falsely great. atmospheric regions Layers of Earth’s atmosphere differ in different model atmospheres; following notes are based on ISA. Lowest layer, troposphere, extends from SL to about 8 km (26,000 ft) at poles, to 11 km (36,090 ft) in temperate latitudes, and to 16 km (52,000 ft) over tropics. Throughout this region ISA characteristics of tempera- ture, pressure and relative density are precisely plotted. Assumed lapse rate is 6.5°C km –1 and at tropopause, taken in ISA to be 11 km (36,090 ft), temperature is –56.5°C. From tropopause stratosphere extends at almost constant temperature but falling pressure to 30 km, stratopause, above which is mesosphere. Here there is reversed lapse rate, temperature reaching peak of about 10°C at 47.35–52.43 km, thereafter falling again to minimum of 180.65°K at mesopause (79.994–90.000 km). Above this is ionosphere, extending to at least 1,000 km, where temperature again rises through 0°C (273°K) at about 112 km and continues to over 1,000°C at 150 km and to peak of about 1,781°C at 700 km. Between 100–150 km lies E (Kennelly-Heaviside) layer; at 200–400 km is F (Appleton) layer, which at night is single band but by day divides into F1 and F2, F2 climbing to 400–500 km on summer day. E and F layers are reflective to suitable EM radiation striking at acute angle. Above ionosphere is open-topped exosphere, from which atmos- pheric molecules can escape to space and where mean free path varies with direction, being greatest vertically upward. Other ** are based upon composition, electrical properties and other variables. atmospheric tides Produced by gravitational attraction of Sun and Moon. Latter exerts small influence, equal to equatorial pressure difference of 0.06 mb, but solar ** has 12 h harmonic component (apparently partly thermal) of 1.5 mb in tropics and 0.5 in mid-latitudes. atmospheric turbulence See gust, CAT. ATMS 1 Air-traffic management system[s]. 2 Advanced-technology microwave sounder. ATN 1 Aeronautical telecommunications network. ATLB ATN 64 2 Air-traffic network. Atnavics Air-traffic navigation integration and co- ordination system (USA). ATNM Air-traffic network management. ATNP ATN(1) panel. ATNS Air-traffic [and] navigation services. ATO 1 Air task, or tasking, order. 2 Assisted takeoff. 3 Abandoned takeoff. 4 Abort to orbit, ie cannot avoid making a complete orbit. 5 Airborne tactical officer. 6 Auto [reporting of] time over[head]. 7 Authorization to offer. ATOA Air Taxi Operators Association (UK). Atoc(s) Allied tactical operations centre(s) (NATO). A to F Authority to fly. ATOL Air travel organiser’s (or operator’s) licence (UK, a major function is to protect passenger after bank- ruptcy of carrier). Atol Advanced trainer on localizer. Atoll Assembly/test oriented launch language. ATOM Aileron trim offset monitor. atom bomb Colloq., fission bomb; very loosely, any NW (see nuclear weapon). atomic materialization Growth of thin-film coating by bombardment with ions and clusters [IR stealth]. atomic number Symbol Z, number of protons in atomic nucleus or number of units of positive electronic charge it bears. atomic weight Mass of atom of element in units each 1/12th that of atom of carbon 12 (refined to 12.01115 on 1961 table). Numerical value for each element is same as atomic mass. atomising Continuous conversion of solid or liquid, esp. high-pressure jet of liquid, into spray of fine particles. Also called atomisation. ATOP Airline training orientation program (US). Atops Advanced transport operating systems (NASA). ATOS 1 Automated technical-orders system. 2 Air Transportation Oversight System (FAA). ATP 1 At time, place. 2 Actual track pointer. 3 Authority to proceed. 4 Aviation technical regiment (USSR). 5 Application transaction program (SNA). 6 Airborne [USAF, Advanced] targeting pod. 7 Air-transport pilot [ALTP is preferred]. 8 Advanced tow placement, manufacturing process for precise composite structure. 9 Air-turbine pump. 10 Allied technical publication. 11 Attack plot. 12 Acceptance-test procedure. ATPAC Air-Traffic Procedures Advisory Committee (US). ATPCS Automatic takeoff power control system. ATPL Airline [or air] transport pilot’s licence; ALTP licence; /H adds endorsement for helicopters [required to be PIC of civil aircraft Ȅ20,000 kg MTOW]. ATR Air, or airline, transport radio, Arinc system of standardizing dimensions of airborne electronics boxes, thus ATR, ½ATR, ¼ATR etc; broadly defined by Arinc 404, has also been said to mean air-transport[able] rack[ing]. 2 Air Transport Rating. 3 Automatic, or aided, target recognition. 4 Airport terminal resources. 5 Air-traffic requirements. 6 Anti-transmit receive. 7 Analog tape recorder. 8 Advanced tactical radar. 9 Armed turn[a]round. 10 Attained turn-rate. 11 Advanced threat resolution, a baggage-screen work- station. 12 Automated time-recording. Atran Automatic terrain recognition and navigation, cruise-missile guidance, Goodyear from 1949. ATRB Advanced Technology Review Board. ATRC 1 Air transport, or traffic, regulation center (US). 2 See next. ATR/C Automatic, or aided, target recognition and classification. ATRD Active towed radar decoy. Atrel Air-transportable reconnaissance exploitation laboratory (RAF). Atrif Air Transportation Research International Forum (Int.). ATRJ Advanced threat radar jammer. ATRP Air-Transport Regulation Panel (ICAO). ATS 1 Air Traffic Services, thus * route (ICAO). 2 Applications technology satellite, wide research programme. 3 Suomen Avaruustutkimusseura Ry (Finnish astro- nautical society). 4 Automatic throttle system. 5 Armament training station (UK, WW2). 6 Aircrew training system (USAF). 7 Automatic test system (or station) for LRU check away from aircraft. 8 Aviation training ship (RN). 9 Air-turbine starter. 10 Acoustic tracking system. 11 Accelerator test stand [U adds upgrade]. 12 Agile target system. 13 Auxiliary Territorial Service (UK WW2, became WRAC). 14 Advanced tracking system (radar extractor/tracker). ATSA 1 Aviation and Transportation Security Act (US, 19 November 2001). 2 Airline and travel services architecture. 3 Air-Traffic Services Agency (Bulgaria). ATSB 1 Air Transportation Stabilization Board (FAA). 2 Australian Transport Safety Board. ATSC 1 Air Technical Service Command (USAAF). 2 Air Traffic Services Cell, or comunication (FAA/DoD). AT/SC Autothrottle/speed control. ATSCC Air Traffic Service Command Center. ATSD Air-traffic situation display. ATSG Acoustic test signal generator. ATSGF ATS(1) geographic filter. ATSM ATS(1) message [P adds processor]. Atsora Air traffic service[s] outside regulated airspace. Atnavics Atsora 65 Comprises RAS, RIS, FIS and non-radar procedural services. ATSS Air Transport Security School (UK, RAF). ATSU ATS(1) unit. ATSy Air Transport Security Section (RAF). ATT 1 Automatic attitude hold (AFCS). 2 Advanced tactical [or theater] transport. 3 Advanced theater threat. 4 Automatic target tracking. A TT Tail-on-tail aerodynamic influence coefficient. attach To place temporarily in a military unit. attached shockwave Caused by supersonic body having leading edge or nose sufficiently sharp or pointed not to cause shock to detach and move ahead of it. Critical values of M at which shock will just remain attached; eg for cone of 30° included angle shock will detach below 1.46; for 30° wedge M is 2.55 because wedge exerts larger obstructing effect on airflow. In most supersonic aircraft aim is to keep most shocks attached, especially at engine inlets. attack aircraft Combat aircraft, usually aeroplane but sometimes helicopter, designed for attacking surface targets of tactical nature; missions include CAS (3) and interdiction. attack, angle of Angle α between wing chord or other reference axis and local undisturbed airflow direction. There are several ways of measuring this crucial parameter. One is absolute angle of attack. Another is *** for infinite aspect ratio, which assumes two-dimensional flow. Effective *** varies greatly with aspect ratio; modern wings of low aspect ratio have no stall in conven- tional sense even at α = 40°. Some authorities in UK cause confusion by using ‘angle of incidence’, which already has clear meaning unconnected with angle of incident airflow. attack avionics Navigation and weapon-aiming systems, often integrated into single ‘fit’ for particular attack- aircraft type. ATTC 1 Automatic takeoff thrust control. 2 Aviation Technical Test Center (USA, Ft Rucker). 3 Aircraft Tactics Training Center (USAF). attention-getter Prominently positioned caption in cockpit, or esp. flight deck, triggered by onboard malfunction or hazardous situation (eg potential mid-air collision) immediately to flash bright amber or red. Less strident caption, warning light or other visual and/or aural circuit also triggered, enabling crew to identify cause and, if possible, take remedial action. Where CWS is fitted first task is to trigger ** while routing appropriate signal to captioned warning panel or other more detailed in- formation. attenuation Loss of signal strength of EM radiation, esp. broadcast through atmosphere, due to geometric spread of energy through volume increasing as cube of distance, loss of energy to Earth, water vapour, air and possibly ionised E and F layers. attenuation factor Ratio of incident dose or dose rate to that passing through radiation shield. ATTG Automated tactical target graphic[s]. AT 3 , AT3, AT- three See ATTT. Attinello flap Blown flap. ATTITB Air Transport and Travel Industry Training Board (UK). attitude Most, if not all, aircraft * described by relating to outside reference system three major axes OX/OY/OZ (see axes); * of flight relates these mutually perpendicular co-ordinates to relative wind; * with respect to ground relates axes to local horizontal. attitude control system, ACS Control system to alter or maintain desired flight attitude, esp. in satellite or space- craft to accomplish this purpose in Earth orbit or other space trajectory. Typical *** uses sensing system, referred to Earth’s limb, star or other ‘fixed’ point or line, and imparts extremely small turning moments to structure by means of gas jets or small rocket motors. In some cases passive *** used (PACS), or vehicle stabilized by spin about an axis, with portions despun if necessary. attitude gyro Loosely, gyro instrument designed to indi- cate attitude of vehicle. Specif., instrument similar to artifical horizon but with 360° freedom in roll and prefer- ably 360° freedom in pitch. Also applicable to conventional horizon with restricted indications of move- ment in aircraft not intended for aerobatics. attitude jet 1 Reaction jet imparting control moments to aircraft at low airspeed (see RCS). 2 Sometimes applied to small thrusters or attitude motors used for same purpose on spacecraft. attitude motor Small rocket motor used to control atti- tude of space vehicle (see thruster, reaction control engine). attitude reference symbol Usually an inverted T giving heading and pitch attitude in HUD symbology. ATTLA Air transportability test-loading agency (US). ATTMA Advanced transport technology [or tactical transport] mission analysis. ATTN Attention. atto Prefix, 10 –18 , symbol a; thus, 1 am (attometre) = 0.000000000000000001 m. attrition Wastage of hardware in operational service, esp. of combat or other military aircraft. attrition buy Additional increment of production run ordered to make good anticipated attrition over active life of system. attrition rate Usually means average [actual or predicted] loss per year. attrition ratio Many meanings, none of which compare losses with those of enemy. ATTS Air-transportable towed system. ATTT Advanced tactical targeting technology. ATTU 1 Atlantic to the Urals (NATO). 2 Advanced Tactics and Training Unit ATU 1 Antenna, or automatic, tuning unit. 2 Aerial [or aircraft] target unit. ATUA Air Transport User’s Association (UK). ATUC See AUC. Atugs Armed tactical unattended ground sensor. ATV 1 Associazione Tecnici di Volo Aviazione Civile (I). 2 Automated transfer vehicle, also called space tug. 3 Atmospheric test vehicle. 4 Aircrew training vessel (UK MoD). AT-Vasi Abbreviated T-Vasi, ten light units on one side of runway in single 4-unit wing bar plus 6-unit bisecting longitudinal line. ATVC Ascent thrust-vector control. ATVS Advanced TV seeker. ATW Advanced tactical workstation. A TW Wing-on-tail aerodynamic influence coefficient. ATWGS Advanced tactical weapon guidance system. ATSS ATWGS 66 A2I2 Accelrated-accuracy improvement initiative (Navstar/GPS). ATWS Active tail-warning system. ATZ Aerodrome traffic zone. AU, a.u. Astronomical Unit. AU 1 Air University (Maxwell AFB, USAF, founded 15 March 1946). 2 Utility aircraft (USA, USAF, 1956–62). AUC Air Transport Users’ Council (CAA, UK). audio box, audio control Governs voice communication and broadcast throughout aircraft and by telephone to ground crew. audio frequency Frequency within range normally heard as sound. Limits vary widely with individuals but normally accepted 15 Hz to 20 kHz, upper limit being depressed with advancing age. audio integration unit Interlinks ‘classic’ cockpit with TCAS, EGPWS and other newer audio systems. audiometer Instrument for measuring subject’s ability to hear speeches and tones at different frequencies. audio oscillator Multi-valve (tube) or multi-transistor stage in superheterodyne receiver serving as local oscil- lator and amplifier (detector). audio speed signal Aural indication of vehicle speed, either on board or at ground station; usually has pitch proportional to sensed velocity, indication being qualita- tive only (see aural high-speed warning). audio warning Loud warning by horn, buzzer, bell or voice tape in headphones or cockpit loudspeaker indi- cating potential danger. Examples: incorrect speed (usually sensed airspeed) for regime, configuration or other flight condition; potentially dangerous excursion of angle of attack; ground proximity; incorrect configura- tion (gear up, wings at maximum sweep, etc). Audist Agence Universitaire de Documentation et d’Information Scientifiques et Techniques (F). audit Comprehensive detailed examination of aiframe structure of aircraft in line service, esp. after fatigue prob- lems encountered on type. AUEW Amalgamated Union of Engineering Workers (UK). AUF 1 Airborne use of force (USCG). 2 Australian Ultralight Federation. AUFP Average unit flyaway price. auger in To crash, esp to fly into ground. augmentation 1 Boosting propulsive thrust by auxiliary device, esp. by afterburning in both core and bypass flows of turbofan. 2 Percentage of thrust added by (1). 3 Increasing inadequate natural flight stability of aero- dyne by on-board system driving control surfaces (rarely, ad hoc auxiliary surfaces). 4 Enhancing target signature of radar, optical, IR or other radiation by means of corner reflectors, Luneberg lenses or other * devices. 5 Enhancement of fluid flow by ejector effect, esp of lift airflow in powered-lift aircraft. augmentation choke Pilot-controlled modulating valve in blowing system of CCW for roll control. augmentation ratio Ratio of total fluid flow to mass flow of primary ejector flow of hot gas in ejector-lift system. augmented deflector (or deflected) exhaust nozzle Nozzle of V/STOL jet engine downstream of augmentor and capable of deflecting flow through at least 90°C. augmented turbojet, turbofan Engine equipped with afterburning (reheat) to augment thrust, esp. at transonic or supersonic flight speed. Turbofan augmentation may be in hot and/or cold flows, latter offering greater density of free oxygen. augmentor Afterburner for turbofan, with burning in hot and cold flows; US often augmenter. augmentor ejector Main lifting system in ejector lift. augmentor wing General term for STOL aeroplane wing in which engine thrust is directly applied to augment circu- lation and thus lift. Countless variations, but most fundamental division is into external and internal blowing. Former typically uses engine bleed air (rarely, total efflux) discharged at sonic speed through one or more narrow slits ahead of large double or triple-slotted flaps which, because of blowing, can be depressed to unusually sharp angle. Second method uses either engine bleed air or total efflux to blow through flap system itself (or propulsion engines are distributed across main flap, in some schemes there being as many as 48 small engines). Internal blowing makes flow separation impossible and gives large downwards component of thrust, but is diffi- cult to apply and may severely compromise aircraft in cruise (see jet flap, blown flap, externally blown flap, upper- surface blowing). AUM Air-to-underwater missile (USA DoD weapon category). AUP 1 Advanced unitary penetrator. 2 Avionics upgrade program. AUR 1 All-up round. 2 Airplane [aircraft, aeroplane] upset recovery. AURA 1 Advanced UHF radar. 2 Autonomous unmanned reconnaissance aircraft. aural acquisition Acquisition of target by IR seeker head as confirmed by pilot’s headset. aural high-speed warning System triggered by sensed flight speed, usually presented as EAS, significantly above allowable maximum. In transport aircraft typically triggered 10 kt above V mo and 0.01 Mach above M mo . Not usually made to do more than warn crew. aural null Condition of silence between large regions where sound is heard, eg in early radio DF system, in some types of beacon passage (‘cone of silence’) and several ground-test procedures. Aurora Automatic recovery of remotely-piloted aircraft. aurora Luminescence in upper atmosphere, esp. in high latitudes, associated with radiation and/or particles travelling along Earth’s magnetic field and at least partly coming from Sun. Exact mechanism not yet elucidated, but 12 classes identified, based on appearance and structure. AUS Airspace utilisation section, part of ATC service. AUSA Association of the US Army. Ausrire Anglicization of ‘all-union scientific research institute of radio equipment’ (R). Austaccs Australian automatic command and control system. austenitic steel Ferrous alloys with high proportions of alloying elements and with microstructure transformed by heat treatment to consist mainly of solid solution of austenite (iron carbide in iron, face-centred). Used to make highly stressed aerospace parts, such as turbine discs. A2I2 austenitic steel 67 AuTC Autothrottle control. AUTEC Atlantic Undersea Test and Evaluation Center (USN with UK help, in British territory). AUTH Authorized. authority 1 Organisation empowered to pronounce hardware properly designed, constructed and maintained, and to issue appropriate certificates. 2 Extent to which functioning system is permitted to control itself and associated systems. Greater * demands greater inherent or acquired reliability, typical means of acquiring reliability being to increase redundancy and provide alternative control channels or in some other way provide for failure-survival. Authorization Act of Congress establishing a Federal agency or procedure (US). Auto-Acas Automatic air-collision avoidance system. Autob Automatic observation and reporting of weather. Autocarp, Auto-CARP Automatic computed air release point. autoclave Pressure chamber which can be heated; oven which can be pressurized. Large * can accept major struc- tural parts of aircraft for adhesive bonding operations. auto coarse pitch System used on a few multi-piston engine aircraft to minimise drag after engine failure. Autodin Automatic digital network (USAF). autodyne oscillator Multi-electrode valve or transisor stage of superheterodyne receiver serving as both local oscillator and amplifier or detector (demodulator). autofeathering System for automatically and swiftly feathering propeller when engine fails to drive it; usually triggered by NTS. autoflare Flare [1] commanded by autopilot. autogenic training Psycho-physiological technique carried out by subject according to prescription by quali- fied therapist, to reduce stress. Autogiro Registered name of Juan de la Cierva auto- gyros, 1924–45. autogyro Rotorplane in which propulsion is effected by horizontal-thrust system, eg propeller, and lift by rotor free to spin under action of air flowing through disc from below to above (ie, autorotating). Some can achieve VTOL by driving rotor in vertical phases of flight, but true * is STOL. auto-hover Automatic hover, usually at low altitude, by helicopter or other VTOL aircraft, using radio altimeter and AFCS. auto-igniting propellant Hypergolic. auto-ignition 1 Of gas turbine engine, auxiliary system which senses angle of attack or other aerodynamic parameter and switches on igniter circuits before engine is fed grossly disturbed airflow which would otherwise pose combustion-extinguishing hazard. In some aircraft flight in rough air with full flap, or flight at high AOA, can cause intermittent or total flame-extinction, and there are other flight conditions (eg violent manoeuvre) when turbulent flow across intake triggers *, indicated by cockpit lights. 2 Specific meaning, ignition of premix fuel/air because of high compression (OPR 45+). 3 Of combustible material, spontaneous combustion. auto-ignition temperature At which auto-igniting materials spontaneously combust in air; design factor in some rocket engines and gas generators. autokinesis Sensation of movement of a distant light that is stared at. Autoklean Patented (UK) lubricating-oil filters based on compressed stack of strainer discs and spacers. Autoland 1 Loosely, AFCS capable of landing aero- plane hands-off and qualified to do so in total absence of pilot visual cues. 2 Specific systems developed in UK by Smiths Industries and GEC-Marconi-Elliott. Autolycus ASW detection system operating by sensing minute atmospheric concentrations of material likely to have come from diesel submarine running submerged (UK). Automap Trade name for map and/or track guide projection system, esp. for single-seat combat aircraft. Automated Radar Terminal System Shows terminal controller basic information on all collaborating traffic. * I largely overtaken by * II, and by III which tracks/predicts secondary-radar targets. * IIIA adds primary targets. All forms now modular and program- mable. (FAA). automatic boost control, ABC On piston engine servo system which senses induction pressure and so governs boost system that permissible limits of boost pressure cannot be exceeded. These were among first airborne closed-loop feedback systems. automatic coarse pitch See Automatic pitch coarsening. automatic dependent surveillance Global system to compensate for lack of radar coverage over oceans and remote areas, involving automatic regular polling of navaids of each aircraft so that ATC can always monitor its position and ensure safe separation. Satellites appear to be essential for implementation. automatic-direction finder See ADF. automatic extension gear Landing gear which extends by itself, typically by sensing airspeed and engine rpm, should pilot omit to select DOWN. automatic feathering Autofeathering. automatic flagman Electronic installation in ag aircraft to provide precise track guidance on each run in con- junction with ground beacons. automatic flyback vehicle Unmanned shuttle between Earth and spacecraft. automatic frequency control 1 Radio receiver which self- compensates for small variations in received signal or local oscillator. 2 By different method, self-governing of a time base. automatic gain control See AGC. automatic landing Safe, precisely repeatable landing of advanced aeroplane, helicopter or other aerodyne in visi- bility so restricted that external visual cues are of no asistance to pilot. Basis of present systems is high- precision ILS, approach coupler, triplexed or quad AFCS, autothrottle, autoflare and ground guidance after touchdown. automatic manoeuvre device system Automatically schedules high-lift devices, especially on variable-sweep aircraft; usually governed by AOA. automatic manual reversion Fully powered flight- control system may be so designed that no ordinary pilot could control aircraft manually; if not, *** on one, two or three axes allows pilot to drive surfaces giving control in those axes after malfunction of powered system can no longer be accommodated by failure-survival. automatic mixture control In piston engine, subsystem which automatically adjusts flow rate of fuel to counteract AuTC automatic mixture control 68 changes in air density, or which controls intake airflow by restricting carburettor air-intake duct by amount inversely proportional to altitude until wide open at height usually around 15,000 ft. automatic observer Self-controlled group of sensors for recovering parameters during flight test. automatic parachute 1 Parachute pulled from its pack by static line [usual meaning]. 2 Parachute opened by barometric device at preset pressure altitude[s]. automatic pilot See autopilot. automatic pitch-coarsening Facility built into propeller control system causing it to increase pitch automatically, normally from fine-pitch setting to typical cruise angle, when called for by operating regime. This is normally another name for a CSU, and quite distinct from auto coarse pitch. automatic power reserve Special increased-thrust rating available on commercial turbofan engines only in emer- gency, and triggered automatically by loss of power in other engine in same aircraft. automatic pull-up Preprogrammed steep climb by (1) aircraft in TFR flight following failure of one pitch channel, or (2) aerial target at start of parachute recovery. automatic RDF See ADF. automatic reverse pitch Facility built into propeller control system causing it to reduce pitch automatically past fine-pitch stop through zero to reverse (braking) position, upon receipt of signal from microswitch triggered when main gears compress shock struts on landing. Very rare for reverse pitch to be obtainable without deliberate selection by pilot, though with *** pilot may select in air, leaving auto system to send opera- tive signal. automatic riveter Machine for drilling holes through parts to be joined, inserting rivet and closing (heading) it. automatic roll-out guidance, AROG Steering guidance after automatic landing in blind conditions (ideally extended from runway turnoff to terminal parking). automatic search jammer ECM intercept receiver and jamming transmitter which searches for and jams all signals having particular signatures or characteristics. automatic selective feathering 1 Airborne subsystem which, in the event of engine failure in multi-engined aircraft (invariably aeroplane), decides which engine has failed and takes appropriate action to shut down and feather propeller. 2 Similar system which, when pilot presses single feathering button, routes signal automatically to failed engine and propeller. automatic slat Leading-edge slat pulled open automati- cally at high angle of attack by aerodynamic load upon it. All slats were originally of this type. automatic synchronization In multi-engined aircraft (invariably aeroplane), subsystem which electrically locks rpm governors of all engines to common speed. automatic terminal information service See ATIS. automatic threat countering Ability of EW system to detect, identify, locate and respond to each hostile emission without human intervention. automatic touchdown release Device incorporated in sling system for external cargo carried below helicopter or other VTOL aircraft which releases load as soon as sling tension is released. automatic tracking Although this could have meaning in system constraining aircraft to follow preset tracks over Earth’s surface, universal meaning is property of direc- tionally aimed system to follow moving target through sensing feedback signal from it. Applications found in (1) air-superiority fighter, in which essential to lock-on and track aerial target automatically, by means of radar, IR, optics or other system; and (2) ground tracking station, which may need to follow satellite, aircraft, drone target or other moving body in order to sustain command system, interception system, data-transmission system or other directionally beamed link. automatic VHF D/F Ground D/F system in which, instead of requiring manual turning of aerial array to find null position, signal from aircraft causes aerial to rotate automatically to this position, direction being at once displayed as radial line on CRT of the equipment. Also called CRT D/F, CRT/DF. automatic voice advice In terminal ATC, computer- generated voice message broadcast to two or more aircraft warning of potential conflict. Intended primarily for VFR traffic and for all traffic not under immediate control, and intended to relieve controller of function that appears to be safely automated. automatic voice alerting device Uses digitized human voice to warn of impending or hazardous situation, warn- ings being arranged in order of priority. autonomous 1 Of aircraft or other vehicle, not needing GSE. 2 Of an SSR, not co-located. 3 Of airborne equipment, not needing external sensors; not linked to other aircraft systems (though possibly under pilot control), eg * reconnaissance pod. autonomous formation flight Saving up to 20% fuel by copying geese and using accurate GPS to place at least one wingtip in tip vortex of preceding aircraft (NASA/Boeing/UCLA). autonomous landing guidance Based upon sensors or other devices in the aircraft. autonomous logistics information system Monitors all significant functioning parts of an organism, predicts expected life and gives advance warning of failure. autonomous vehicle Vehicle, especially unmanned aircraft, which completes mission without external help. autopilot Airborne electronic system which automati- cally stabilizes aircraft about its three axes (sometimes, in light aircraft, only two, rudder not being served), restores original flight path following any upset, and, in modern *, preset by pilot or remote radio control to cause aircraft to follow any desired trajectory. In advanced aircraft * is integral portion of AFCS and can be set by dial, push- button or other control to capture and hold any chosen airspeed, Mach, flight level or heading. In avanced combat aircraft * receives signals from sensing and weapon-aiming systems enabling it to fly aircraft along correct trajectories to fire guns or other ordnance at aerial target or lay down unguided bombs on surface target. autopilot-disconnect Advanced autopilots are automati- cally disconnected by control overloads generated within aircraft and by certain other disturbances likely to reflect wish of pilot, eg triggering of stall-protection stick- pusher. Autoplan Portable EDP which digitises navigation plan and combines output with other CPGS data to provide automatic observer Autoplan 69 attack-aircraft pilot with complete nav/ECM/weapon- aiming information. auto power reserve See automatic **. autopsy Searching examination of crashed aircraft to discover cause, esp. to detect fatigue failure. autorotation 1 Loosely, condition in which airflow past aircraft causes whole aircraft or significant part of it to rotate. Propeller in this context is not significant, though windmilling propeller is autorotating. 2 In helicopter, descent with power off, air flowing in reverse direction upwards through lifting rotor(s), causing it to continue to rotate at approximately cruise rpm. Pilot preserves usual control functions through pedals, cyclic and collective, but cannot grossly alter steep ‘glide path’. Rate of descent may exceed design ROD for landing gear, but is reduced just before ground impact by sudden increase in collective pitch; this increases lift, trading stored rotor kinetic energy for increased aerodynamic reaction by blades, and should result in gentle touchdown. 3 In aeroplane, descent in stalled condition, with general direction of airflow coming from well beyond stalling angle of attack but in grossly asymmetric con- dition (see spin). 4 In aeroplane, descent in unstalled condition under conditions apparently not greatly different from straight and level but with stabilized spiral flight path (see spiral dive, spiral stability). Distinct case of * which purist might argue is incorrect usage. 5 In helicopter flying training, range of manoeuvres designed to increase confidence and remove fear of power failure; all power-off descents, but differ in whether they are NPR (no power recovery) or terminated at height well above ground by restoring at least partial power. In latter case * terminated either by run-on-landing (running *), run-on climb-out or moderate-flare climb-out. auto-separation Automatic (often barometric) release of occupant from ejection seat. Autosevocom Automatic secure-voice communications (DoD). autostabilizer Loose term for autopilot, esp with authority on pitch axis only. Autosyn Trade name for remote-indicating system in which angular position of indicator needle precisely follows rotary sensing device moved by fluid level, mechanical displacement or other parameter which must be remotely measured. Sensor and indicator are essen- tially synchronous electric motors. autosynchronization Automatic synchronisation. autothrottle Power control system for main propulsion engines linked electro-mechanically to AFCS and automatic-landing system so that thrust is varied auto- matically to keep aircraft on glide path and taken off at right point in autoflare; in general * will also call for reverse thrust at full power in conjunction with automatic track guidance (roll-out guidance), though this may be left to discretion of pilot. autotracking Signal processing technique that enables a target to be automatically acquired and tracked by means of its own image, which can be received at any operating wavelength (usually microwave or optical). autotrim Aircraft trim system automatically adjusted by autopilot or other stabilising system to alter or maintain aircraft attitude according to pilot demand or changed distribution of weight or aerodynamic load. Usually governs pitch only, the autopilot commanding the elevator and the autotrim the tailplane (stabilizer). Autovon Automatic voice network (USAF Communications Service). AUVS Association for Unmanned Vehicle Systems [I adds International] (US). AUW, a.u.w. All-up weight; actual aggregate weight of particular laden aircraft at moment of weighing. For generalized equivalent, more precise term should be used (MRW, MTOW, etc), but AUW has advantage of being not explicit and thus can be used to mean ‘total weight of aircraft, whatever that happens to be’. Should never be used to mean MRW or MTOW. If latter are not known, preferred term meaning ‘maximum allowable weight’ is gross weight. AUWE Admiralty Underwater Warfare Establishment (UK). AUWG Airspace Users Working Group. AUX Auxiliary. auxiliary bus Secondary electrical bus serving one or more devices and often maintained at voltage different from that of main bus. auxiliary fin Generally, small additional fixed fin carried, not necessarily to enhance directional stability, well outboard on tailplane. auxiliary fluid ignition In rocket engine, use of limited supply of hypergolic fluid(s) to initiate combustion of main propellants. auxiliary inlet, auxiliary intake Extra inlet to [invariably gas-turbine] engine to admit extra air when needed [normally only on takeoff]. Also called supplementary air inlet and, most commonly, suction-relief door. auxiliary parachute Pilot parachute. auxiliary power unit, APU Airborne power-generation system other than propulsion or lift engines, carried to generate power for airborne system (electrics, hydraulics, air-conditioning, avionics, pressurization, main-engine starting, etc). In general, term restricted to plant deriving energy from on-board source and supplying constant- speed shaft power plus air bleed. This would exclude a RAT or primitive windmill-driven generator. Some *** can provide propulsive thrust in emergency (see MEPU ). auxiliary rigging lines Branching from main parachute rigging lines to distribute load more evenly around canopy. auxiliary rotor In a classical helicopter [one main rotor], the rotor provided to counter drive torque and control fuselage azimuth. This is preferably called the tail rotor. auxiliary tank Fuel tank additional to main supply, esp. that can readily be removed from aircraft (see reserve tank, external tank, drop tank). AV 1 Air vehicle. 2 Audio-visual. 3 Aft vectoring (nozzle mode). AVA 1 Automatic voice advice. 2 Applied vector analysis. AVAD Automatic voice alert[ing] device. AVADS Autotrack Vulcan air-defense system (USA). aval, Aval Available. availability 1 Symbol A, proportion of time aircraft is serviceable and ready for use, expressed as decimal frac- tion over period or as number of hours per day or days per month. Also expressed as . uptime –––––––––––––––– uptime + downtime auto power reserve availability 70 [...]... Pilots’ Association AWPG Advanced weather products generator AWR Airborne weather radar AWRA Augmentor-wing research aircraft AWRE Atomic Weapons Research Establishment [Aldermaston, now AWE] (UK) AWRS 1 Airborne weather reconnaissance system (USAF) 2 Automatic weather reporting system AWS 1 Air Weather Service (USAF, formerly part of MAC, now an FOA, Scott AFB) 2 Audible (or advanced) warning system... blades in helicopter main motor 6 Bit[s] 7 Propeller axial slipstream factor B1, B2 Graduation ratings from CFS b1 Control-surface hinge moment b2 Rate of change of surface hinge moment dCH/d⑀ B2B Business to business B2C Business to consumer B2H6 Diborane rocket propellant, usually combined with OF2 B4 Aviation petrol (G, WW2) B-category Aircraft used as non-flying trainer B-class 1 Military and civil... struts 2 All-weather intercept 3 Air weapons instructor 4 Airframe/weapons integration Awiator Aircraft wing with advanced-technology operation (Airbus) AWIGWG Aircraft wire and inert-generator working group AWIM Airport weather information manager AWIN, Awin Aviation weather information [S adds system] (NASA/Boeing) Awips Advanced weather interactive processing system (FAA) AWIS Automatic weather information... level AWLS All-weather landing system AWM 1 Average working man (in defining aircrew sleep patterns) 2 Aircraft wiring manual 3 Audio warning mixer AWMDS Automatic wing-sweep and manoeuvre devices system AWNIS Allied worldwide naval information system AWO All-weather operations AWOP All-weather Operations Panel (ICAO) AWOS Automated, or airport, weather-observing, or automatic weather-observation,... (AFRL) 2 Atmospheric-vehicle detection Avdas Airborne-vehicle data-acquisition system AVG 1 Average (ICAO) 2 American Volunteer Group (China, WW2) 3 Aircraft escort vessel (later ACV, then CVE) Avgard Additive to JP-1 and other jet fuels to produce anti-misting kerosene (ICI trade name) Avgas Aviation gasoline, range of piston engine petrols Avometer today being narrowed to 100LL (blue, max 2. 4 ml/Imp... system 5 Area weather system 6 Aircraft Warning Service (USA/USN, 19 42 – 46) Awsacs, AWSACS All-weather stand-off aircraft (or attack) control system (USN) AWSAS All-weather stand-off attack system AWSO Aviation-warfare systems operator AWT 1 Airborne wideband terminal 2 Atmospheric wind tunnel AWT Tail-on-wing aerodynamic influence coefficient AWTA Advise what time available AWTSS All-weather tactical... adverse-, weather aerial delivery system AWAM Association of Women in Aviation Maintenance (US) Awans Aviation weather and notice-to-airmen system (FAA, from 1976) Awards 1 Aircraft wide-angle reflective display system 2 All-weather airborne reconnaissance drone sensor Aware Advanced warning of active-radar emission[s] Awas Automated weather advisory system AWB 1 Airway bill, air waybill 2 Above-water... quarters (US armed services) BAR See * UK bar 1 Unit of pressure, allowed within SI and standard in meteorology and many other sciences Equal to 105 Nm 2 = 14.5037 lb/in2 In units contrary to SI, 106 dynes cm 2 or 750.08 mm; 29 .53 in of Hg One bar (1,000 mb) is Normal Atmospheric Pressure 2 Metal [usually gold] bar(s) across ribbon of medal to show decoration has been awarded twice (thrice); in written... such as APU, cabin compressor or vectored nozzle(s) barf bag Sick bag Barif Bureau of Airlines Representatives in Finland barn 1 Unit of area for measuring nuclear crosssections Equal to 10 28 m2 or 10 22 mm2 Symbol b 2 Non-hardened hangar for single aircraft, eg SR–71 barnstormer Formerly, itinerant freelance pilot who would operate from succession of unprepared temporary airfields giving displays and... base of 2, instead of common base of 10 Thus 43 (sum of 25 , 23 , 21 and 20 ) is written 101011 All binary numbers are expressed in terms of two digits, 0 and 1 Thus digital computer can function with bistable elements, distinction between a 0 or 1 being made by switch being on or off, or magnetic core element being magnetised or not binary phase modulation Radar pulse-compression technique in which the phases . equal to 101, 325 Nm -2 = 101, 325 Pa = 1,013 .25 mb = 1.01 325 bars or hectopièze = 14.6959 lbf in -2 = 761.848 mm (29 .994 in) Hg at 16.6°C. Second is Metric * (also ata) equal to 0.986 42 Standard. many other sciences. Equal to 10 5 Nm 2 = 14.5037 lb/in 2 . In units contrary to SI, 10 6 dynes cm 2 or 750.08 mm; 29 .53 in of Hg. One bar (1,000 mb) is Normal Atmospheric Pressure. 2 Metal. Finland. barn 1 Unit of area for measuring nuclear cross- sections. Equal to 10 28 m 2 or 10 22 mm 2 . Symbol b. 2 Non-hardened hangar for single aircraft, eg SR–71. barnstormer Formerly, itinerant