View source for Airco DH.9A

{{short description|1918 bomber aircraft by Airco}}
{{Use British English|date=July 2014}}
{{Infobox aircraft
  |name = DH.9A
  |image = File:Airco D.H.9A ExCC.jpg
  |caption = Airco D.H.9A
  |type = [[Light bomber]]/General purpose
  |manufacturer = [[Airco]]
  |designer =
  |first_flight = March 1918
  |introduction = 1918
  |retired = 1931
  |primary_user = [[Royal Air Force]]
  |more_users = [[Soviet Air Forces]]<br>[[Royal Australian Air Force]]<!--30-->
  |number_built = 1,997 + 2,400+ as R.1
  |developed_from = [[Airco DH.9]]
  |variants =[[Westland Walrus]] <br> [[de Havilland DH.15]]
}}

The '''Airco DH.9A''' is a British single-engined light bomber that was designed and first used shortly before the end of the [[First World War]]. It was a development of the unsuccessful [[Airco DH.9]] bomber, featuring a strengthened structure and, crucially, replacing the under-powered and unreliable inline 6-cylinder [[Siddeley Puma]] engine of the DH.9 with the American V-12 [[Liberty 12|Liberty]] engine.

Colloquially known as the "Ninak" (from the [[RAF phonetic alphabet|phonetic alphabet]] treatment of designation "nine-A"), it served on in large numbers for the [[Royal Air Force]] following the end of the war, both at home and overseas, where it was used for colonial policing in the Middle East, finally being retired in 1931. Over 2,400 examples of an unlicensed version, the '''Polikarpov R-1''', were built in the Soviet Union, the type serving as the standard Soviet light bomber and reconnaissance aircraft through the 1920s.

==Design and development==
The DH.9A was planned as an improved version of the existing [[Airco DH.9]]. The DH.9 was a disappointment owing to its under-performing and unreliable engines, and the DH.9A was to use a more powerful engine to resolve this. As the [[Rolls-Royce Eagle]] engine used in the successful [[Airco DH.4|DH.4]] was unavailable in sufficient quantities, the new American {{cvt|400|hp}} [[Liberty L-12|Liberty]] engine was chosen instead.

As [[Airco]] was busy developing the [[Airco DH.10 Amiens]] twin-engined bomber, detailed design was carried out by [[Westland Aircraft]]. The DH.9 was fitted with new, longer-span wings and a strengthened fuselage structure.<ref name="Jackson DH p107">Jackson 1987, p. 107.</ref>

The first prototype flew in March 1918, powered by a Rolls-Royce Eagle as no Liberty engines were yet available.<ref name="Bruce ptI p643">Bruce 25 May 1956, p. 643.</ref> The prototype proved successful, with the first Liberty-engined DH.9A flying on 19 April 1918, and deliveries to the [[Royal Air Force]] starting in June.<ref name="Bruce ptI p644">Bruce 25 May 1956, p. 644.</ref> By the end of the war, a total of 2,250 DH.9As had been ordered, with 885 being built by the end of the year. As it was decided that the DH.9A would be a standard type in the postwar RAF, the majority of outstanding orders were fulfilled, with 1,730 being built under the wartime contracts before production ceased in 1919.

While the existing aircraft were subject to a programme of refurbishment, a number of small contracts were placed for new production of DH.9As in 1925–26. These contracts resulted in a further 268 DH.9As being built. The new production and refurbished aircraft included batches of dual control [[Trainer (aircraft)|trainers]], as well as six aircraft powered by {{cvt|465|hp}} [[Napier Lion]] engines, which were capable of a maximum speed of {{cvt|144|mph}}.

The Soviet Union built large numbers of an unlicensed copy of the DH.9A, the '''R-1'''. After the production of 20 DH.4 copies, followed by about 200 copies of the DH.9 powered by the [[Mercedes D.IV]] engine (also designated R-1) and a further 130 powered by the [[Siddeley Puma]] (designated R-2), a copy of the DH.9A powered by the M-5 engine, a Soviet copy of the DH.9A's Liberty, entered production in 1924.<ref name="Alex p55-6">Alexandrov and Petrov 1998, pp. 55–56.</ref> The '''Polikarpov R-4''' was a modification of the R-1, with the engine lowered and moved forward by {{cvt|140|mm|in}} to improve both the forward visibility and the C.G position. The nose shape was improved by fairing and by installing a retractable ventral radiator. Overall length was increased by {{cvt|389|mm|in}}. Landing legs were changed from wood to steel. Testing showed insufficient improvement over the R-1 to justify production but late R-1s incorporated some of the modifications.<ref name="Gunston p287-8">Gunston 1995, p.287-8.</ref>

===US version and pressurised flights===
The United States also planned to adopt the DH.9A as a replacement for the DH.4. Development work on the Americanization of the aircraft commenced at [[McCook Field]] in [[Dayton, Ohio]].<ref name="Cornelisse pp. 120–121"/> Modifications included a new fuel system with increased fuel capacity, revised wings and tail surfaces, and replacement of the [[Vickers machine gun]] on the port side of the British built aircraft with a Browning machine gun on the starboard side.<ref name="Bruce pt 2 p677"/><ref name="Jackson p108-0, 19">Jackson 1987, pp. 108–110, 119.</ref> Plans called for [[Curtiss Aeroplane and Motor Company|Curtiss]] to build 4,000 modified aircraft, designated '''USD-9A'''.  This order was cancelled with the end of the war and only nine were built by McCook Field and [[Dayton-Wright Company|Dayton-Wright]].<ref name="Bruce pt 2 p677"/><ref name="Jackson p108-0, 19"/> One McCook aircraft was additionally modified with an enclosed, [[Cabin pressurization|pressurised cockpit]]. In 1921, test pilot Lt. Harold R. Harris made the world's first high-altitude flight in a pressurised aircraft in the USD-9A at McCook Field in Dayton, Ohio.<ref name="Cornelisse pp. 120–121">Cornelisse 2002, pp. 120–121.</ref>

==Operational history==

===First World War===
The DH.9A entered service in July 1918 with [[No. 110 Squadron RAF]], moving to France on 31 August 1918 to serve with the RAF's [[Independent Air Force]] on strategic bombing missions. Its first mission was against a German airfield on 14 September 1918.<ref name="Bruce ptI p644"/> A further three squadrons commenced operations over the Western Front before the Armistice, with [[No. 99 Squadron RAF|99 Squadron]] (also serving with the Independent Air Force) replacing DH.9s, while [[No. 18 Squadron RAF|18 Squadron]] and [[No. 216 Squadron RAF|216 Squadron]] replaced DH.4s.<ref name="Bruce ptI p644"/> Despite the superior performance of the DH.9A over the DH.9, the DH.9A squadrons suffered high losses during their long range bombing missions over Germany.<ref name="Williams p201">Williams 1999, p. 201.</ref> Other squadrons flew coastal patrols from [[Great Yarmouth]] before the end of the year.

The [[United States Marine Corps]] [[Northern Bombing Group]] received at least 53 DH-9As, and commenced operations in September 1918.<ref name="Bowyer profile p29">Bowyer 1974, p. 29.</ref>

===Interwar RAF service===
<!--  Commented out: [[File:600 DH 9A.jpg|thumb|Three DH.9A in formation.]] -->
While the squadrons in service at the end of the First World War quickly disbanded or re-equipped in the postwar dis-armament, the DH.9A continued in service as the RAF's standard light bomber, with 24 squadrons being equipped between 1920 and 1931, both at home and abroad.

The first post war operations were in southern Russia during 1919, in support of the "[[White Army]]" against the [[Bolsheviks]] during the [[Russian Civil War]]. In September 1919, the RAF personnel were ordered to return home, leaving their aircraft behind.<ref name="Bruce pt 2 p677">Bruce 1 June 1956, p.677.</ref> A squadron of DH.9As was deployed to [[Turkey]] in response to the [[Chanak Crisis]] in 1922, but did not engage in combat.<ref name="Thetford p19">Thetford 1992, p. 193.</ref>

The DH.9A was one of the key weapons used by Britain to manage the territories that were in its control following the collapse of the [[Ottoman Empire]] following the Great War. Five squadrons of DH.9As served in the Middle East,<ref name="Mason bomber p103">Mason 1994, p.103.</ref> occasionally carrying out bombing raids against rebellious tribesmen and villages. An additional radiator was fitted under the fuselage to cope with the high temperatures, while additional water containers and spares (including spare wheels lashed to the fuselage) were carried in case the aircraft were forced down in the desert, the DH.9A's struggling under ever heavier loads. Despite this the aircraft served successfully, with the Liberty engine being picked out for particular praise for its reliability ("as good as any Rolls Royce") in such harsh conditions.<ref name="mason p104">Mason 1994, p. 104.</ref> Some DH.9A aircraft were also transported to [[India]] to supplement the [[British Indian Army]].

At home, the DH.9A continued on in regular RAF service until 1930, also forming the initial equipment of the [[Royal Auxiliary Air Force]] (RAuxAF).

===Soviet service===
The R-1 and R-2 were heavily used by the [[Soviet Air Forces]] through the 1920s as its standard light bomber and reconnaissance aircraft. The Soviets deployed them in support of the Chinese [[Kuomintang]] forces in the [[Northern Expedition (1926–1927)|Northern Expedition]] against warlords in 1926–27, and against Chinese forces for [[Sino-Soviet conflict (1929)|control of the Chinese Eastern Railway]] in [[Manchuria]] in 1929. R-1s and R-2s were also used in support of operations during the [[Basmachi Revolt]] in central Asia.<ref name="Alex p61-3">Alexandrov and Petrov 1998, pp. 61–63.</ref>

==Variants==
* '''Airco DH.9A:'''  Original version.
* '''de Havilland DH.9AJ:''' Single prototype with [[Bristol Jupiter]] engine.
* '''de Havilland DH.9R:''' Racing aircraft with sesquiplane wings and powered with a Napier Lion engine – (one built).
* '''[[de Havilland DH.15|Airco DH.15 Gazelle]]''': DH.9A fitted with a [[Galloway Atlantic]] inline engine, one conversion
* '''[[Airco DH.16]]:''' Civil transport with widened fuselage seating four passengers in a glazed cabin behind the pilot, who sat in an open cabin, nine built.  Rolls Royce Eagle or Napier Lion Engine.
* '''de Havilland DH-49''' – proposed modernised version with Eagle IX engine (not built)
* '''Engineering Division USD-9A:'''  United States built version, 9 built. One modified with a pressurised cockpit.
* '''Engineering Division USD-9B:'''  USD-9A fitted with more powerful Liberty engine and greater area wings.<ref name="Bruce pt 2 p677"/>
* '''Armstrong Whitworth Tadpole'''  One prototype conversion for a naval three-seat spotter/reconnaissance aircraft.
* '''[[Westland Walrus]]'''  Production version of the Tadpole conversion with the Napier Lion III engine (36 built).
[[File:R-1 ISKRA.jpg|thumb|Polikarpov R-1]]
* '''Polikarpov R-1''' and '''R-2''' Copy of DH.9A built in the [[Soviet Union]], originally at the [[Dux Factory]], supervised by [[Nikolai Nikolaevich Polikarpov]]. Early aircraft were powered by [[Mercedes D.IV]] or [[Armstrong Siddeley Puma]] engines, but most were powered by the M-5 copy of the Liberty Engine. Over 2,400 built from 1922 to 1932.<ref name="Gunston p286">Gunston 1995, p.286.</ref>
* '''Polikarpov R-1 BMW:''' R-1 fitted a {{cvt|240|hp}} [[BMW IV]]a engine, 20 built.
* '''Polikarpov MR-1:''' Twin-float seaplane version, 124 built.
* '''Polikarpov PM-2:''' Prototype floatplane fitted with metal floats.
* '''Polikarpov R-4:''' R-1 with better forward view and CG position, forward profile cleaned up with fairings and a retractable ventral radiator. Stronger [[landing gear]]. No production but changes incorporated into late R-1s.<ref name="Gunston p287-8"/>

==Operators==
;{{flagu|Afghanistan|1919}}
* [[Afghan Air Force]] – Airco DH.9As and Polikarpov R-1s
;{{AUS}}
* [[Royal Australian Air Force]]: 30 received as an imperial gift in 1920 plus one attrition replacement purchased in 1921.<ref name=adfs1a1>{{cite web|title=RAAF A1 de Havilland D.H.9a|publisher=adf-serials.com.au|work=Australian & New Zealand Military Aircraft Serials & History|last=Crick|first=Darren|url=http://adf-serials.com.au/1a1.htm|date=31 March 2016|access-date=16 May 2020|archive-date=8 March 2020|archive-url=https://web.archive.org/web/20200308061959/http://www.adf-serials.com.au/1a1.htm|url-status=dead}}</ref> It was the first aircraft from the imperial gift to enter Australian service.<ref>Aircraft of the Royal Australian Air Force, 2021. p. 4</ref>  The aircraft were in service from 1920 to 1930, and were replaced by the [[Westland Wapiti]].<ref name="Jackson p110">Jackson 1987, p. 110.</ref>
** [[No. 1 Flying Training School RAAF]] (22 aircraft: A1-1/2/5/7-11/13-21/23/24/26/29/30)
** [[No. 1 Squadron RAAF]] (12 aircraft: A1-4/5/7/9/12/14/20-22/25/26/28)
** [[No. 3 Squadron RAAF]] (8 aircraft: A1-3/6/8/10/24/25/27/28)
** [[Central Flying School RAAF]] (4 aircraft: A1-16/17/26, E8616)
;{{flagu|Canada|1921}}
* [[Canadian Air Force (1918–1920)]]
** [[No. 2 Squadron RCAF|No. 2 Squadron CAF]]{{Sfn|Kostenuk|Griffin|1977|p=8}}
* [[Canadian Air Force (1920–1924)]]
* [[Royal Canadian Air Force]]
;{{flagu|Iran|1925}}
* [[Imperial Iranian Air Force]]
;{{flagu|Latvia}}
* [[Latvian Air Force]]
;{{MGL}}
* [[Mongolian People's Army|Mongolian People's Air Force]] : Polikarpov R-1s and R-2s
;{{POR}}
* [[Portuguese Air Force]]<ref name="AE73 p23">Niccoli 1998, p. 23.</ref>
;{{flagu|Switzerland}}
* [[Swiss Air Force]] : One aircraft only.
;{{UK}}
* [[Royal Air Force]]<ref name="Bowyer Profile p48">Bowyer 1974, p. 48.</ref>
** [[No. 3 Squadron RAF]]
** [[No. 8 Squadron RAF]]
** [[No. 11 Squadron RAF]]
** [[No. 14 Squadron RAF]]
** [[No. 15 Squadron RAF]]
** [[No. 18 Squadron RAF]]
** [[No. 22 Squadron RAF]]
** [[No. 24 Squadron RAF]]
** [[No. 25 Squadron RAF]]
** [[No. 30 Squadron RAF]]
** [[No. 39 Squadron RAF]]
** [[No. 45 Squadron RAF]]
** [[No. 47 Squadron RAF]]
** [[No. 55 Squadron RAF]]
** [[No. 60 Squadron RAF]]
** [[No. 84 Squadron RAF]]
** [[No. 99 Squadron RAF]]
** [[No. 100 Squadron RAF]]
** [[No. 110 Squadron RAF]]
** [[No. 205 Squadron RAF]]
** [[No. 207 Squadron RAF]]
** [[No. 207 Squadron RAF]]
** [[No. 221 Squadron RAF]]
** [[No. 273 Squadron RAF]]
** [[No. 501 Squadron RAF]]
** [[No. 600 Squadron RAF]]
** [[No. 601 Squadron RAF]]
** [[No. 602 Squadron RAF]]
** [[No. 603 Squadron RAF]]
** [[No. 604 Squadron RAF]]
** [[No. 605 Squadron RAF]]

;{{USA}}
* [[United States Navy]]
* [[United States Marine Corps]]
;{{USSR}}
* [[Soviet Air Force]] : Polikarpov R-1s and R-2s

==Surviving aircraft==
[[File:DH9A at RAF Museum London Flickr 4606882763.jpg|thumb|DH.9A number ''F1010'' at the RAF Museum, London in 2010]]
A single example, serial number ''F1010'', survives and is on display at the [[Royal Air Force Museum London]]. The aircraft was completed by [[Westland Aircraft]] in June 1918 and was one of 18 DH.9A's assigned to [[No. 110 Squadron RAF]]. It was the thirteenth aircraft, but was given the number "12A" because thirteen was [[Triskaidekaphobia|thought unlucky]]. The squadron began flying bombing missions in September 1918, and on the 25th, the crew of ''F1010'' claimed the destruction of a German [[Fokker D.VII]] fighter. The aircraft's fourth and final combat mission was on 5 October when either flak damage or engine trouble forced a landing behind German lines. The aircraft was undamaged by the landing and the crew were taken prisoner.<ref name="RAFMuseum" />

The aircraft remained in German hands after the war and in 1936 it was put on display at the ''Deutsche Luftfahrt Sammlung'' (Berlin Air Museum), one of the museum's substantial collection of World War 1 aircraft. In 1943, it was one of the museum's exhibits that was moved to Czarnikau (now [[Czarnkow]] in Poland) to save them from the [[Bombing of Berlin in World War II|Allied bombing of Berlin]]. The area was captured by Polish forces in March 1945 and ''F1010'' eventually became part of the collection of the [[Polish Aviation Museum]], although it was not put on display and remained in the museum's stores. In 1977, the Polish Aviation Museum exchanged ''F1010'' for a [[Supermarine Spitfire]] from the RAF Museum (difficulties caused by the [[Cold War]] meant nearly nine years were spent negotiating the swap). The RAF Museum completed restoration of the aircraft and put it on display in 1983.<ref name="RAFMuseum">{{cite web | url=http://www.rafmuseum.org.uk/documents/collections/77-A-921-DH-DH9A-F1010.pdf | title=Individual History: De Havilland DH9A F1010 Museum Accession Number 77/A/921 | publisher=RAF Museum | year=2013 | access-date=16 April 2016 | last=Simpson | first=Andrew | archive-url=https://web.archive.org/web/20160425141904/http://www.rafmuseum.org.uk/documents/collections/77-A-921-DH-DH9A-F1010.pdf | archive-date=25 April 2016 | url-status=dead }}</ref>

==Specifications (DH.9A)==
[[File:Polikarpov R-1.svg|thumb|DH.9A]]
{{Aircraft specs
|ref=''The British Bomber since 1914''<ref name="mason p105">Mason 1994, p. 105.</ref>
|prime units?=imp<!-- imp or kts first for US aircraft, and UK aircraft pre-metrification,
met(ric) first for all others. You MUST choose a format, or no specifications will show -->
<!--General characteristics-->
|crew=2
|length ft=30
|length in=3
|span ft=45
|span in=11+3/8
|height ft=11
|height in=4
|wing area sqft=486.75
|airfoil=
|empty weight lb=2800
|max takeoff weight lb=4645
<!--Powerplant-->
|eng1 number=1
|eng1 name=[[Liberty L-12|Liberty 12A]]
|eng1 type= water-cooled [[V-12 engine]]
|eng1 hp=400<!-- prop engines -->
|prop blade number=<!-- propeller aircraft -->
|prop name=
|prop dia ft=<!-- propeller aircraft -->
|prop dia in=<!-- propeller aircraft -->
|prop dia note=
<!--Performance-->
|max speed mph=123
|max speed note=at sea level, {{convert|114.5|mph|km/h kn|abbr=on}} at {{convert|10000|ft|m|abbr=on}}
|range miles=
|endurance=5 h 25 min<!-- if range unknown -->
|ceiling ft=16750
|time to altitude=15 min 45 s to {{cvt|10000|ft}}
<!--Armament-->
|guns=
** 1 × forward firing {{cvt|.303|in}} [[Vickers machine gun]],
** 1 or 2 × {{cvt|.303|in}} [[Lewis gun]]s on [[Scarff ring]]
|bombs= Up to {{cvt|740|lb}} on under-wing and fuselage racks
}}

==See also==
{{aircontent
|related=
* [[Airco DH.9]]
* [[Westland Wapiti]]
* [[Westland Wallace]]
|similar aircraft=
|lists=
* [[List of aircraft of the RAF]]
* [[List of bomber aircraft]]
|see also=
}}

==Notes==
{{reflist|2}}

==Bibliography==
*''[https://books.google.com/books?id=X0wrEAAAQBAJ Aircraft of the Royal Australian Air Force]''. Simon and Schuster, 2021. {{ISBN|9781922488046}}
* Alexandrov, Andrei and Gennady Petrov. "Aah! De Havilland-Ski!: Origins and Development of the R-1, the Soviet DH.9A". ''[[Air Enthusiast]]'', No. 74, March/April 1998. pp. 54–63. {{ISSN|0143-5450}}.
* Bowyer, Chaz. "de Havilland D.H.9A (RAF: 1918–30)". ''Aircraft in Profile, Volume 14''. Windsor, Berkshire, UK: Profile Publications Ltd., 1974, pp. 25–49. {{ISBN|978-0-85383-023-8}}.
* Bruce, J.M. "[http://www.flightglobal.com/pdfarchive/view/1956/1956%20-%200641.html The De Havilland D.H.9A: Historic Military Aircraft No.13, Part I]". ''[[Flight International|Flight]]'', 25 May 1956, pp. 641–644.
* Bruce, J.M. "[http://www.flightglobal.com/pdfarchive/view/1956/1956%20-%200677.html The De Havilland D.H.9A: Historic Military Aircraft No.13, Part II]". ''[[Flight International|Flight]]'', 1 June 1956, pp. 677–680.
* Cornelisse, Diana G. ''Splendid Vision, Unswerving Purpose: Developing Air Power for the United States Air Force During the First Century of Powered Flight''. Wright-Patterson Air Force Base, Ohio: US Air Force Publications, 2002. {{ISBN|0-16-067599-5}}.
* Donald, David, ed. The Encyclopedia of World Aircraft. London: Aerospace Publishing, 1997. {{ISBN|1-85605-375-X}}.
* Gunston, Bill. ''The Osprey Encyclopedia of Russian Aircraft from 1875–1995''. London: Osprey Aerospace, 1995. {{ISBN|1-85532-405-9}}.
* Jackson, A.J. ''De Havilland Aircraft since 1909''. London: Putnam, Third edition, 1987. {{ISBN|0-85177-802-X}}.
* {{Cite book|title=RCAF: Squadron Histories and Aircraft, 1924–1968|last1=Kostenuk|first1=Samuel |last2=Griffin |first2=John|publisher=Samuel Stevens/Hakkert & Company|year=1977|isbn=0-88866-577-6 |series=Canadian War Museum Historical Publication No. 14|location=Sarasota/Toronto}}
* Mason, Francis K. ''The British Bomber since 1914''. London: Putnam Aeronautical Books, 1994. {{ISBN|0-85177-861-5}}.
* Niccoli, Riccardo. "Atlantic Sentinels: The Portuguese Air Force Since 1912". ''[[Air Enthusiast]]'', No. 73, January/February 1998. pp 20–35. {{issn|0143-5450}}
*Sims, Charles. "Talkback". ''[[Air Enthusiast]]''. No. 13, August–November 1980. p. 79. {{ISSN|0143-5450}}
* Thetford, Owen. "By Day and By Night: Part 3". ''Aeroplane Monthly'', Vol. 20, No. 8, Issue No. 232, August 1992, pp. 16–22. London: IPC.  ISSN 0143-7240.
* Williams, George K. ''Biplanes and Bombsights: British Bombing in World War I''. Maxwell Air Force Base, Alabama: Air University Press, 1999. {{ISBN|1-41020-012-4}}.

==External links==
{{Commons category}}
* [https://www.youtube.com/watch?v=kOU78bhu7iI 1918 silent film of DH.9As being manufactured in the US]

{{De Havilland aircraft}}
{{Polikarpov aircraft}}
{{Soviet scout designations}}
{{ADF aircraft designations}}
{{Use dmy dates|date=July 2014}}

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