Auster AOP.9

{{short description|British military observation aircraft}} {{Use dmy dates|date=September 2019}} {{Use British English|date=July 2017}} {{Infobox aircraft |name = Auster AOP.9 |image = File:Auster - RIAT 2005 (2531884786).jpg |caption = AOP.9 XR244 at the RIAT 2005 |type = military observation aircraft |manufacturer = Auster Aircraft Limited |designer =  |first_flight = 19 March 1954 |introduction = 1955 |retired =  |status =  |primary_user = Army Air Corps |more_users = Royal Air Force, Indian Air Force |produced =  |number_built = 182<ref name="Simp"/> |unit cost = |developed_from = |variants = }}

The '''Auster AOP.9''' was a British military air observation aircraft ("air observation post") produced by Auster Aircraft Limited to replace the Auster AOP.6.

==Design and development== The Auster AOP.9 was designed as a successor to the Auster AOP.6. Like its predecessor, it was a braced high-wing single engined monoplane with a fixed tailwheel undercarriage.<ref name ="JAWA1956">{{Harvnb|Bridgman|1956|pages=46–47}}</ref> Although having the same general appearance, the AOP.9 was a new design, with larger wing area and a more powerful engine. The wing and tail were metal-skinned, but the fuselage and ailerons were fabric-covered.<ref name="JAWA1956"/> The fin and rudder assembly were more angular in the new aircraft with a noticeable dorsal fillet.<ref>{{Harvnb|Thetford|1957|pages= 37, 39}}</ref> A combination of the more powerful 180 hp (134 kW) Blackburn Cirrus Bombardier engine, larger wings and large flaps gave it an improved take-off and landing performance compared with the AOP.6. It could operate from ploughed fields and muddy surfaces using low pressure tyres and strengthened undercarriage.<ref name="Thet">{{Harvnb|Thetford|1957|page=38}}</ref>

The cabin held three seats, pilot and passenger side-by-side and the observer behind, facing either forwards or rearwards.<ref name="JAWA1956"/> The aircraft was also designed to be convertible into a two-seat light transport with an interchangeable rear floor.<ref name="Thet"/> In this configuration the observer sat alongside the pilot.

The prototype ''WZ662'' first flew 19 March 1954.<ref name="JAWA1956"/> Auster Aircraft allotted its model designation '''B5''' to the AOP.9 design.<ref name="Ketley, 2005, p. 83">{{Harvnb|Ketley|2005|p=83}}</ref>

==Operational history== Deliveries started to the Royal Air Force in February 1955,<ref name="JAWA1956"/> replacing AOP.6s in the regular AOP squadrons, the auxiliary squadrons disbanding in March 1957 before receiving AOP.9s. Until the formation of the Army Air Corps (AAC) in September 1957, Army personnel flew RAF aircraft based in RAF squadrons.

The aircraft were in action with No. 656 Squadron from September 1955,<ref>{{Harvnb|Halley|1988|p=447}}</ref> flying an average of 1,200 sorties per month.<ref>{{Harvnb|Ketley|2005|p=50}}</ref> By the end of Operation Firedog in Malaya on 31 July 1960, 656 Squadron's AOP.6 and AOP.9s had carried out 143,000 sorties.<ref>{{Harvnb|Thetford|1976|p=42}}</ref>

The AOP.9s were involved in several of Britain's other end of Empire conflicts; 653 Squadron AAC used them in Aden in the early 1960s, flying from Falaise, Little Aden.<ref name="MAF">{{Cite web |url=http://www.flying-museum.org.uk/the_army_air_corps_today.htm |title=Museum of Army Flying |access-date=3 June 2009 |archive-url=https://web.archive.org/web/20090302011644/http://flying-museum.org.uk/the_army_air_corps_today.htm |archive-date=2 March 2009 |url-status=dead }}</ref><ref name="Aden">[http://www.adenairways.com/AAC.htm AOP.9 in Aden]</ref> They stayed in service until 1966 and were the last fixed wing AOP aircraft used by the AAC,<ref name="MAF"/> though their light transport role was taken over by Beavers.

thumb|right|Formerly XR240, this aircraft now (2008) flies as ''G-BDFH''

The South African Air Force operated its AOP.9s from 1957 to 1967.

The Army Historic Aircraft Flight maintain an AOP.9<ref>[http://www.army.mod.uk/7354.aspx British Army AOP.9] {{webarchive |url=https://web.archive.org/web/20110605031314/http://www.army.mod.uk/7354.aspx |date=5 June 2011 }}</ref> in flying condition at Middle Wallop.

In the 1970s, 19 AOP.9s joined the UK civil register, and in 2008 14 remained, though only about three of these had a current certificate of airworthiness.<ref>[http://www.caa.co.uk/application.aspx?catid=60&pagetype=65&appid=1&mode=summary&aircrafttype=Auster%20AOP.9 UK Civil Aviation Authority Aircraft Register Auster AOP.9]</ref> The sole Beagle E3/Auster AOP.11 ''G-ASCC'' was flying<ref name="CAA">[http://www.caa.co.uk/application.aspx?catid=60&pagetype=65&appid=1&mode=detailnosummary&fullregmark=ASCC UK Civil Aviation Authority Aircraft Register G-ASCC]</ref> until an accident in 2007.<ref>[http://www.aaib.gov.uk/publications/bulletins/october_2007/beagle_aircraft_e3__auster_aop_ii___g_ascc.cfm G-ASCC crash]</ref>

==Variants== [[File:Auster AOP.9 XK417 Farnborough 09.56.jpg|thumb|right| AOP.9 XK417 at the Farnborough Airshow in 1956, this aircraft served No. 652 Squadron RAF]] ;Auster AOP.9 :Only production version, 182 built.<ref name="Simp"/> ;Auster AOP.11 :Three-seat AOP machine with a 260 hp Continental IO-470-D 6-cylinder horizontally opposed more powerful engine, that raised the maximum speed to 142 mph (228 km/h) and the empty weight to 1,806 lb (816 kg).<ref name="JAWA66"/> Apart from the engine, the AOP.11 was almost identical to its predecessor. Early in its career, the undercarriage had spats, though these were later removed.<ref name ="JAWA66">{{Harvnb|Taylor|1966|pages=140–141}}</ref> Only one, a converted AOP.9<ref name="Simp"/> was produced, making its first flight on 18 August 1961 with serial ''XP254''.<ref>{{Harvnb|Taylor|1966|page=140}}</ref> A year later it was registered to Beagle aircraft, that had taken over Auster in 1960, as ''G-ASCC'' where it was known as the Beagle Mk 11, the E.3 or as the A.115.<ref name="Simp">{{Harvnb|Simpson|2001|page=52}}</ref> It was sold into private hands in 1971.<ref name="CAA"/>

;Auster 9M :A number of army surplus aircraft were bought by Captain Mike Somerton-Rayner in 1967. One was converted as an Auster 9M with a 180 hp (134 kW) Avco Lycoming O-360-A1D piston engine.<ref name="Jackson1974">{{Harvnb|Jackson|1974|page=325}}</ref> The 9M first flew on 4 January 1968, and gained a Certificate of Airworthiness on 30 April 1968<ref name="Jackson1974" /> The aircraft was still airworthy in 2009.<ref>[http://www.caa.co.uk/docs/HistoricalMaterial/G-AVHT.pdf UK Civil Aviation Authority Aircraft Register G-AVHT (historic)] {{webarchive |url=https://web.archive.org/web/20110606160132/http://www.caa.co.uk/docs/HistoricalMaterial/G-AVHT.pdf |date=6 June 2011 }}</ref><ref>[http://www.caa.co.uk/application.aspx?catid=60&pagetype=65&appid=1&mode=detailnosummary&fullregmark=AVHT UK Civil Aviation Authority Aircraft Register G-AVHT (current)]</ref>

==Operators== ===Military operators=== thumb|Privately owned 1961-built AOP.9 ''G-AZBU'' takes off in 2009 ;{{flag|Hong Kong|colonial}} *Royal Hong Kong Auxiliary Air Force about 4 ex-British AAC aircraft *various ACC AOP and Independent Flights stationed in Hong Kong in the 1950s and 1960s ;{{IND}}: 35 aircraft *Indian Air Force *Indian Army ;{{flag|South Africa|1928}}: *South African Air Force Two aircraft **No 42 Squadron SAAF ;{{UK}}: 146 aircraft *Army Air Corps<ref name="Ketley, 2005, p. 83"/> **653 Squadron<ref name="MAF"/> **656 Squadron **Advanced Fixed Wing Flight **Army Flights: 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 14, 16, 18, 20, 21. **Various Army Regiments *Royal Air Force<ref>{{Harvnb|Halley|2001|p=51}}</ref> **652 Squadron (January 1956 – September 1957)<ref name="Jefford102">{{Harvnb|Jefford|1988|p=102}}</ref> **656 Squadron (September 1955 – September 1957)<ref name="Jefford103">{{Harvnb|Jefford|1988|p=103}}</ref> **Light Liaison Flight, South Korea **Christmas Island Flight, 160 Wing<ref name="SturtivantHamlin297">{{Harvnb|Sturtivant|Hamlin|2007|p=297}}</ref> **1900 Flight<ref name="SturtivantHamlin130">{{Harvnb|Sturtivant|Hamlin|2007|p=130}}</ref> at Hong Kong **No. 38 Group Communication Flight<ref name="SturtivantHamlin156">{{Harvnb|Sturtivant|Hamlin|2007|p=156}}</ref> at Upavon **Light Aircraft School at Middle Wallop<ref name="SturtivantHamlin173">{{Harvnb|Sturtivant|Hamlin|2007|p=173}}</ref>

==Specifications (AOP.9)== {{Aircraft specs |ref=<ref name="JAWA1956"/> |prime units?=imp  |genhide=

|crew=3 |capacity= |length m= |length ft=23 |length in=8+1/2 |span m= |span ft=36 |span in=5 |height m= |height ft=8 |height in=11 |wing area sqm= |wing area sqft=197.6 |wing area note= |aspect ratio= |airfoil=NACA 23012 |empty weight kg= |empty weight lb=1460 |empty weight note= |gross weight kg= |gross weight lb=2100 |gross weight note= |fuel capacity={{convert|16|impgal|USgal L|abbr=on}} (normal) |more general=  |eng1 number=1 |eng1 name=Blackburn Cirrus Bombardier 203 |eng1 type=4-cylinder inverted inline piston |eng1 kw= |eng1 hp=173 |prop blade number= |prop name=Fairey-Reed fixed pitch |prop dia m= |prop dia ft= |prop dia in= |prop note=  |perfhide= |max speed kmh= |max speed mph=127 |max speed kts= |max speed mach= |cruise speed kmh= |cruise speed mph=110 |cruise speed kts= |never exceed speed kmh= |never exceed speed mph= |never exceed speed kts= |range km= |range miles=242 |range nmi= |endurance= |ceiling m= |ceiling ft=18500 |ceiling note= (absolute ceiling) |g limits= |roll rate= |climb rate ms= |climb rate ftmin=920 |lift to drag= |wing loading kg/m2= |wing loading lb/sqft= |wing loading note= |more performance={{blist|'''Takeoff run in {{cvt|6|mph|km/h kn}} headwind:''' {{cvt|324|ft|m}} |'''Takeoff distance to 50 ft (15 m) in 6 mph headwind:''' {{convert|630|ft|m|abbr=on|0}} |'''Landing run in 6 mph headwind:''' {{cvt|180|ft|m}} |'''Landing distance from 50 ft (15 m) in 6 mph headwind:''' {{convert|450|ft|m|abbr=on|0}} }}  |armament= * Optional 4 x {{cvt|4|in|mm}} flares in under-fuselage light-bomb carrier |guns= |bombs= |rockets= |missiles= |hardpoints= |hardpoint capacity= |hardpoint rockets= |hardpoint missiles= |hardpoint bombs= |hardpoint other=

|avionics= }}

==See also== {{Portal|Aviation}} {{aircontent |related= * Auster AOP.6 |similar aircraft= |sequence= |lists= *List of aircraft of the Royal Air Force *List of aircraft of the Army Air Corps (United Kingdom) |see also= }}

==References==

===Notes=== {{reflist|colwidth=20em}}

===Bibliography=== {{refbegin}} *{{cite book |last=Bridgman |first=Leonard |title=Jane's All the World's Aircraft 1956-7 |year=1956 |publisher=Jane's All the World's Publishing Co. Ltd }} *{{cite book |last=Halley |first=J.J. |title=The Squadrons of the Royal Air Force 1918–1988 |year=1988 |publisher=Air-Britain (Historians) Ltd |isbn=0-85130-164-9 }} *{{cite book |last=Halley |first=J.J. |title=Royal Air Force Aircraft |year=2001 |publisher=Air-Britain (Historians) Ltd |isbn=0-85130-311-0 }} *{{cite book |last= Jackson |first= A.J. |title= British Civil Aircraft since 1919 Volume 1 |year= 1974 |publisher= Putnam |location= London |isbn= 0-370-10006-9 }} *{{cite book |last= Jefford |first= C.G. |title= RAF Squadrons |year=1988 |publisher= Airlife Publishing Ltd |isbn= 1-85310-053-6 }} *{{cite book |last=Ketley |first=Barry |title=Auster – A brief history of the Auster aircraft in British military service |year=2005 |publisher=Flight Recorder Publications |isbn=0-9545605-6-6 }} *{{cite book |last=Simpson |first=Rod |title=Airlife's World Aircraft |year=2001 |publisher=Airlife Publishing Ltd |location=Shrewsbury |isbn=1-84037-115-3 }} *{{cite book |last1=Sturtivant|first1=Ray|last2=Hamlin|first2=John|title=Royal Air Force flying training and support units since 1912 |year=2007 |publisher= Air-Britain (Historians)|location=Tonbridge, UK|isbn=978-0851-3036-59}} *{{cite book |last=Taylor |first=J.W.R. |title=Jane's All the World's Aircraft 1966-7 |year=1966 |location=Great Missenden |publisher= Sampson Low, Marsden & Co. Ltd. }} *{{cite book |last= Thetford |first=Owen |title= Aircraft of the Royal Air Force 1919–57|year=1957|publisher= Putnam|location= London }} *{{cite book |last=Thetford |first=Owen |title=Aircraft of the Royal Air Force since 1918 |year=1976 |publisher=Putnam & Company Ltd |isbn=0-370-10056-5}} *{{cite book |title= The Illustrated Encyclopedia of Aircraft (Part Work 1982–1985) |publisher= Orbis Publishing}} {{refend}}

==External links== {{commons category-inline|Auster AOP.9}}

{{DEFAULTSORT:Auster Aop.9}} Category:High-wing aircraft Category:Single-engined tractor aircraft Category:1950s British military reconnaissance aircraft A.O.P.9 Category:Aircraft first flown in 1954 Category:Aircraft with fixed conventional landing gear Category:Single-engined piston aircraft