View source for Airco DH.9

{{Short description|1917 bomber aircraft family by Airco}}
{{Use dmy dates|date=March 2020}}
{{Infobox aircraft
  |name = DH.9
  |image = Airco_D.H.9.jpg
  |caption = Airco DH.9
  |type = [[Bomber]]
  |manufacturer = [[Airco]]
  |designer = [[Geoffrey de Havilland]]
  |first_flight = July 1917
  |introduction = November 1917
  |retired = 1937
  |primary_user = [[Royal Air Force]]
  |more_users = [[Royal Flying Corps]]<br>[[Royal Naval Air Service]]<br>[[South African Air Force]]
  |number_built = 4,091
  |variants = [[Airco DH.9A]]<br />[[Airco DH.9C]]<br />[[Westland Walrus]]
}}

The '''Airco DH.9''' (from [[Geoffrey de Havilland|de Havilland]] 9) – also known after 1920 as the '''de Havilland DH.9''' – is a British single-engined [[biplane]] bomber that was developed and deployed during the [[World War I|First World War]].

The DH.9 was a development of [[Airco]]'s earlier successful [[Airco DH.4|DH.4]], with which it shared many components. These were mated to an all-new fuselage and the [[Beardmore Halford Pullinger#230 hp BHP engine|230 hp BHP]] engine, which promised increased performance. Anticipating its usefulness, the type was ordered in very large numbers for Britain's [[Royal Flying Corps]] (RFC).

Upon entering service, the DH.9's performance was found to be unsatisfactory. The BHP engine was unreliable and failed to provide the expected power, which gave the DH.9 poorer performance than the aircraft it had been meant to replace. The performance deficit was blamed for the heavy losses they suffered over the [[Western Front (World War I)|Western Front]]. The redesigned [[Airco DH.9A|DH.9A]] was fitted with a more powerful and reliable American [[Liberty L-12]] engine which rectified the shortcomings of the original DH.9 model.

==Development==
===Origins===
During June 1917, partially as a result of attacks by German bombers on [[London]], the [[War Office]] issued its recommendation to almost double the size of the [[Royal Flying Corps]] (RFC) to a total of 200 squadrons. In early July 1917, the [[Cabinet of the United Kingdom|British Cabinet]] accepted the recommendation, with the intention that the majority of the new squadrons planned to be equipped with [[bomber]]s.<ref name="Bruce pt I p387">Bruce 2 April 1956, p. 387.</ref><ref name = "bruce 65 3"/> While an order for 700 DH.4s was placed on 28 June 1917, on 23 July 1917, the Air Board were presented with drawings for a modified DH.4 that delivered greater range under a new type number, DH.9.<ref name = "bruce 65 3"/>

The DH.9 was designed by [[Geoffrey de Havilland|de Havilland]] for the [[Airco|Aircraft Manufacturing Company]] in 1916 as a successor to the [[Airco DH.4|DH.4]]. It used the wings and [[Empennage|tail unit]] of the DH.4 but featured a modified [[fuselage]] which moved the [[Aviator|pilot]] closer to the [[Air gunner|gunner/observer]] and away from the [[Piston engine|engine]] and fuel tank, which facilitated communication and was a more optimal fighting configuration.<ref name = "bruce 65 4"/> The other major change from the DH.4 was the choice of the promising new [[Beardmore Halford Pullinger|B.H.P]] engine, which was predicted to produce {{cvt|300|hp}} to provide adequate performance to match enemy fighters.<ref name="Jackson DHp97"/>

Based on the performance estimates for the DH.9 (which were initially expected to surpass those of the DH.4), and the similarity to the DH.4, which meant that it would be easy to convert production over to the new aircraft, it was decided to place a massive number of orders (totalling 4,630 aircraft) for the type prior to the aircraft even flying for the first time.<ref name = "bruce 65 3"/> Existing contracts originally placed for the DH.4 were also converted to the DH.9. The Air Board had been specifically assured that there would be an initial production delay of no more than a month. According to aviation author J.M Bruce, the selection of the DH.9 "seems to have been taken in a spirit of optimism or blind faith, for its chosen engine was, in July 1917, experiencing serious manufacturing difficulties".<ref name = "bruce 65 3 4">Bruce 1965, pp. 3-4.</ref>

===Into flight===
In July 1917, the prototype (a converted DH.4) performed its [[maiden flight]] from [[Hendon Aerodrome]], [[Colindale]], [[London]].<ref name="Jackson DHp97">Jackson 1987, p. 97.</ref> Trials of the type were extensive, including a number of tests performed at [[RAF Martlesham Heath]].<ref name = "bruce 65 3"/> Unfortunately, the [[Beardmore Halford Pullinger|BHP]] engine proved unable to reliably deliver its expected power; the engine having been de-rated to {{cvt|230|hp}} in order to improve its reliability. This deficit had a drastic effect on the aircraft's performance, especially at high altitude, with it being inferior to that of the DH.4 it was supposed to replace.<ref name = "bruce 65 3"/>

The poor performance of the aircraft meant that the DH.9 would have to fight its way through enemy fighters, which could easily catch the DH.9 where the DH.4 could avoid many of these attacks. As early as November 1917, some officials, such as [[Hugh Trenchard, 1st Viscount Trenchard|General Hugh Trenchard]], raised repeated objections to the aircraft based upon its disappointing performance; however, in his response, [[Secretary of State for Air|President of the Air Council]] [[William Weir, 1st Viscount Weir|Sir William Weir]] started that "it was the choice of having the DH.9 with the B.H.P. engine, or of having nothing at all.<ref name="bruce 65 3">Bruce 1965, p. 3.</ref> Additionally, by this point, production of the DH.9 was already well underway.<ref name="bruce 65 3"/>

BHP engines were produced by [[Siddeley-Deasy]] (developed as the [[Siddeley Puma|Puma]]) and Galloway Engineering (developed as the [[Galloway Adriatic|Adriatic]]). In British military service both Siddeley and Galloway built engines were known as the 230 hp BHP although they had different dimensions and few interchangeable parts.<ref name="Lumsden">{{Cite book |last=Lumsden |first=Alec |title=British Piston Engines and their Aircraft |date=2002 |publisher=Airlife Publishing |isbn=1853102946 |pages=81–86 |language=en}}</ref><ref name="RAFRef">{{Cite book |title=R.A.F Field Service Pocket Book |date=April 1918 |pages=10–11}}</ref> The vast majority of BHP engines in service were built by Siddeley-Deasy.<ref name="Lumsden" />[[File:Record du monde (d')altitude, capitaine Lang, lieutenant Blowes - btv1b532384931.jpg|thumb|Captain Lang and Lieutenant Blowes in front of their World Altitude Record holding Napier Lion powered DH.9.]]Multiple attempts were made to provide the DH.9 with a better engine.<ref name="bruce 65 3 4" /> In August 1917, an order for 2,000 Fiat A12 engines was placed, intending to be delivered between January and June 1918 and used upon some production batches of the D.H9; however, deliveries of the Fiat engine were unsatisfactory.<ref name="bruce 65 4">Bruce 1965, p. 4.</ref>

An alternative powerplant was the {{cvt|430|hp}} [[Napier Lion]] engine.  A Napier Lion powered aircraft piloted by Captain Lang and his observer Lieutenant Blowes achieved a [[Flight altitude record|World Altitude Record]] of {{cvt|30500|ft}} in 66 minutes on 2 January 1919.<ref name="Jackson DHp100">Jackson 1987, p. 100.</ref>   At 21,000 ft Lieutenant Blowes oxygen supply failed and he remained unconscious until the aircraft descended to 10,000 feet. Unaware of his observers plight Captain Lang was unable to exceed 30,500 feet because their oil heater failed and their fuel pumps cut out due to a lack of air pressure.  Both men needed to be hospitalized after the attempt due to frostbite on their faces, hands, and feet.<ref>{{Cite news |date=1919-01-09 |title=An Altitude Record. |url=http://nla.gov.au/nla.news-article59659464 |access-date=2025-06-25 |work=Kilmore Free Press}}</ref>

However, none of these options were deemed to be entirely satisfactory,<ref name = "bruce 65 4"/> it required being redesigned into the DH.9A, for which an American V-12 [[Liberty L-12|Liberty]] engine was adopted, to transform the aircraft. According to Bruce, aside from the engine issue: "Certainly, there was little wrong with the aircraft itself".<ref name = "bruce 65 4"/>

==Design==
The Airco DH.9 was a single-engine [[United Kingdom|British]] bomber aircraft, sharing a high level of similarities with the preceding DH.4.<ref name = "bruce 65 4"/> The standard flight surfaces were broadly the same, but adopted a highly redesigned fuselage configuration, including the repositioning of the pilot's cockpit to a more rearwards position.<ref name = "bruce 65 4 5"/> Structurally, the fuselage was similar to its predecessor; [[plywood]] cladding covered the forward fuselage, which had no internal bracing, while a conventional wire-braced [[box girder]] structure was used aft of the cockpits. Internal stowage for a pair of {{cvt|230|lb}} or four {{cvt|112|lb}} [[bomb]]s was provided for, although little use of this capability was made operationally.<ref name = "bruce 65 4 5">Bruce 1965, pp. 4-5.</ref>

While the DH.9 was deemed to be suitable for daytime bombing operations, it was found to be incapable of effective nighttime bombing due to the pilot's view being obstructed and visibility via the [[bombsight]] being unsuitable.<ref name = "bruce 65 5">Bruce 1965, p. 5.</ref> The revised cockpit positioning of the DH.9 from the DH.4 placed the pilot and the observer closer together, which was viewed by the RAF as being a considerable advantage in aerial combat; however, the pilot's visibility for ground reconnaissance was decreased as a result. Both [[radio]] sets and [[camera]]s could be installed.<ref name = "bruce 65 5"/> The fuel tanks were enclosed in [[Aircraft dope|doped]] fabric, intended to drain fuel away if the tanks were hit by enemy fire. According to the testing squadron, the DH.9 possessed a high level of manoeuvrability, was relatively easy to perform landings aside from a poor view during the approach.<ref name = "bruce 65 5"/>

Various improvements and supplementary equipment were trialled and occasionally adopted.<ref name = "bruce 65 7 8">Bruce 1965, pp. 7-8.</ref> Tests of various engines, [[radiator]]s, [[Muffler|silencer]]s and [[parachute]]s were conducted to evaluate their performance, however, few of these improvements were ultimately adopted. During the war, numerous customisations and improvised improvements were made to the aircraft by the maintenance crews of individual squadrons, often for the purpose of addressing the type's engine performance issues.<ref name = "bruce 65 6 8">Bruce 1965, pp. 6-8.</ref> After the end of the war, many DH.9s, which had been originally delivered as bombers, were sold; these were often reconfigured to serve in different roles, including passenger and cargo transport, [[trainer aircraft]], and as [[air ambulance]]s.<ref name = "bruce 65 8 10">Bruce 1965, pp. 8-10.</ref>

==Operational history==
===First World War service===
To boost the rate of production, quantity orders for the DH.9 were also placed with Alliance, G & J.Weir, Short Brothers, Vulcan, [[Waring & Gillow]] and National Aircraft Factories No. 1 and No. 2. The first deliveries of the type occurred during November 1917 to [[No. 108 Squadron RAF|108 Squadron]] [[Royal Flying Corps|RFC]]; by the end of 1917, a total of five DH.9s had been delivered and passed their final inspections.<ref name = "bruce 65 6">Bruce 1965, p. 6.</ref> The first combat engagement of the type, performed over France, was performed in March 1918 by [[No. 206 Squadron RAF|No. 6 Squadron RNAS]]. By July 1918, a total of nine operational squadrons deployed to the [[Western Front (World War I)|Western Front]] were using the type.

The DH.9's performance in action over the Western Front was typically deemed to have been a disaster; heavy losses of the type were quickly incurred, attributed to both its poor performance and to engine failures, despite the prior derating of its engine to reduce the failure rate.<ref name = "bruce 65 6"/> Between May and November 1918, a pair of squadrons stationed at the Western Front (Nos. [[No. 99 Squadron RAF|99]] and [[No. 104 Squadron RAF|104]]) had 54 of its DH.9s shot down and another 94 aircraft written off due to accidents.<ref name="Masonp85">Mason 1994, p. 84.</ref> On multiple occasions, less than half of a flight of bombers would reach their intended targets; according to Bruce, the successful missions performed by the DH.9 were frequently a product of "the courage and determination of the pilots and observers that flew them". Squadrons would often implement their own home-built enhancements to their aircraft, such as enlarged [[carburetor]] air intakes and modified fuel mixture controls.<ref name = "bruce 65 6"/>

Nevertheless, the type proved capable during some engagements; on 23 August 1918, a DH.9 flown by Lieutenant [[Arthur Spurling|Arthur Rowe Spurling]] of 49 Squadron, with his observer, [[Frank Bell (aviator)|Sergeant Frank Bell]], single-handedly attacked thirty [[Fokker D.VII]] fighters, downing five of them.<ref>{{Cite web|url=http://www.theaerodrome.com/aces/england/spurling.php|title=Arthur Rowe Spurling|website=www.theaerodrome.com}}</ref>{{better source needed|date=December 2021|reason=theaerodrome.com is considered generally unreliable}}<ref>''Lt. Spurling Won Flying Cross'', The Royal Gazette and Colonist Daily (now The Royal Gazette), Hamilton, Bermuda. 19 September 1918.</ref><ref>[http://www.geocities.ws/mhicgherri/raf-image1 POTSI (archived):] Sqn. Ldr. A. Rowe Spurling, DFC</ref> On 9 August 1918, Lieutenant E.A. Simpson of 49 Squadron, while flying a bombing mission upon bridges at [[Falvy]] and [[Bethencourt]], shot down four hostile fighters while defending against repeated attacks upon the formation.<ref name = "bruce 65 7">Bruce 1965, p. 7.</ref> In another instance, Captain [[John Stevenson Stubbs]] achieved 11 aerial victories in a DH.9, including the highly unusual feat of [[balloon buster|balloon busting]] while flying the type.<ref>[http://www.theaerodrome.com/aces/england/stubbs2.php "John Stevenson Stubbs"] ''theaerodrome.com'', Retrieved: 1 May 2011.</ref>{{better source needed|date=December 2021|reason=theaerodrome.com is considered generally unreliable}}

Despite its general lack of performance, due to its large numbers, the DH.9 was introduced to nearly every theatre of the conflict prior to the signing of the [[Armistice of 11 November 1918]], which ended the conflict.<ref name = "bruce 65 7"/> Reportedly, the DH.9 was also more successful in combat against the Turkish forces in the [[Middle Eastern theatre of World War I|Middle East]], where they faced less aerial opposition. Stationed at coastal aerodromes across the British mainland, the type was also used extensively to perform [[maritime patrol aircraft|coastal patrol]] missions with the aim of deterring the operations of enemy [[U-boats]].<ref name = "bruce 65 7"/>

===Post war service===
Following the end of the First World War, a number of DH.9s operated by [[No. 47 Squadron RAF|47 Squadron]] and [[No. 221 Squadron RAF|221 Squadron]] were sent to southern [[Russia]] in 1919 in support of the [[White movement|White Russian]] Army of [[Anton Ivanovich Denikin|General Denikin]], participating in the [[Russian Civil War]].<ref name="Bruce ptII p424"/> In this theatre, the aircraft were often operating within challenging conditions.<ref name = "bruce 65 8">Bruce 1965, p. 8.</ref>

The last combat use of the DH.9 by the RAF was in support of the [[1920 conflict between British forces and Somaliland dervishes|final campaign]] against [[Las Anod#Diiriye Guure|Diiriye Guure]]<ref name="scr">{{cite book |last1=Omar |first1=Mohamed |title=The Scramble in the Horn of Africa |date=2001 |page=402 |quote=This letter is sent by all the Dervishes, the Amir, and all the Dolbahanta to the Ruler of Berbera ... We are a Government, we have a Sultan, an Amir, and Chiefs, and subjects ... (reply) In his last letter the Mullah pretends to speak in the name of the Dervishes, their Amir (himself), and the Dolbahanta tribes. This letter shows his object is to establish himself as the Ruler of the Dolbahanta}}</ref> in [[Somalia]] during January–February 1920.<ref name="Bruce ptII p424">Bruce 13 April 1956, p. 424.</ref> Amongst those aircraft used in Somalia, one DH.9 was modified to function as an [[air ambulance]], being able to load and transport a single stretcher case, which was carried upon the upper [[longeron]]s directly to the rear of the pilot's cockpit.<ref name = "bruce 65 8 9">Bruce 1965, pp. 8-9.</ref> Further ambulance conversions were performed, including a number that were operated by the [[Royal Netherlands Air Force]].<ref name = "bruce 65 9"/>

Production was allowed to continue after the end of the war into 1919. In 1920, the DH.9 was finally withdrawn from service by the RAF.<ref name="masonp86"/> In addition to British manufacturing, several other countries had commenced production of the type; perhaps the most significant of these was the [[Airco DH.9A]], which was fitted with the American V-12 [[Liberty L-12|Liberty]] engine, and was produced in the thousands even though production was curtailed by the signing of the Armistice that had ended the First World War.<ref name = "bruce 65 8"/> [[Belgium]] and [[Spain]] also produced the type, the latter producing hundreds of the type equipped with a {{cvt|300|hp}} [[Hispano-Suiza]] engine; some of these were still in service in 1940.<ref name = "bruce 65 9"/>

Following the end of the conflict, large numbers of surplus DH.9s became available at low prices and the type was widely exported. This included aircraft donated to the [[Dominion]]s and India as part of the [[Imperial Gift]] programme.<ref>{{cite web |last1=Allen |first1=Tiggy |title=Of Camels, WW1 Bombers, Elephant Stables and a Maharaja |url=https://map.sahapedia.org/article/Of-Camels,%20WW1%20Bombers,%20Elephant%20Stables%20and%20a%20Maharaja/10101 |website=map.sahapedia.org |access-date=3 September 2022}}</ref><ref name="Jackson DHp100"/><ref name = "bruce 65 9">Bruce 1965, p. 9.</ref> The [[South African Air Force]] (SAAF) received a total of 48 DH.9s, and used them extensively, including against the [[Rand Revolt]] in 1922. Several South African aircraft were later re-engined with [[Bristol Jupiter]] radial engines as the '''M′pala'''; such modified aircraft continued to serve until 1937.<ref name="Jackson DHp102">Jackson 1987, p. 102.</ref><ref name = "bruce 65 9"/>

Possibly the last battle use by any user was in late 1922, during the [[Turkish War of Independence]].<ref>{{cite web |title=Vecihi Hürkuş Broşür |url=http://www.vecihihurkus.net/brosur3.pdf |access-date=5 May 2023 |archive-url=https://web.archive.org/web/20101025153406/http://www.vecihihurkus.net/brosur3.pdf |archive-date=25 October 2010 |language=tr |date=January 2009}}</ref> Greeks had deployed a number of them against the [[Kemalists]] who were fighting the British supported Greek Army invading the remaining chunk of the [[Ottoman Empire]] after the 1918 [[Armistice of Mudros]] followed by the [[Sevres Treaty]] which was rejected by the nationalists. One of Greek DH.9s had made a forced landing behind Turkish lines near [[Muğla]] during the [[Battle of Sakarya]] previous year, sometime in July 1921. This machine was quickly repaired and was flown to Ankara in August 1921 by famous pilot [[Vecihi Hürkuş]].<ref>{{Cite web|url=https://www.fikriyat.com/biyografi/2018/07/16/havacilikta-ilklerin-adami-vecihi-hurkus|title = Havacılıkta ilklerin adamı: Vecihi Hürkuş}}</ref> It was named "Ismet". It was deployed, as the only Turkish airplane at the time, in the last phases of the Battle of Sakarya, making a total of 23 sorties, mostly by Vecihi.<ref name="tayyareci.com">{{Cite web|url=http://www.tayyareci.com/digerucaklar/turkiye/kurtulus/dh9.asp|title = DH 9 .. War independence Period TUAF {{sic|AIRCRAFTS|nolink=y}} Kurtulus savasi dönemi Turk HVKK UCAKLARI}}</ref> Same airplane continued to serve for the remaining of the War of Independence through 1922. There were three more Greek DH.9s found in excellent condition, with plenty of spare parts, near [[İzmir]] after the Greek army pulled out hurriedly, having been routed by Kemalists in August 1922. These four planes served the young [[Turkish Air Force]] until 1925.<ref name="tayyareci.com"/>

The [[Irish Free State]] purchased surplus six DH.9s from the [[Aircraft Disposal Company]], these being received in January–February 1923. They were used for reconnaissance, army support and protection of railways during the last few months of the [[Irish Civil War]]. The DH.9 remained in Irish service into the 1930s.<ref name="am1015p37">London 2015, p. 37</ref>

===Civilian service===
[[File:G-AUED.jpg|thumb|DH-9 G-AUED modified with a cabin for use as an airliner]]
After the end of the war, large numbers of surplus DH.9s became available, having been deemed to be surplus to requirements by their original military operators; accordingly, many were resold onto civil operators, such as by early aerial transport companies. Large numbers were modified to better perform as transport aircraft, such as the cabin being suitably adapted for the carriage of passengers.<ref name = "bruce 65 9"/> In this role, the DH.9 provided a useful load carrying capability and was relatively inexpensive to procure. Accordingly, in various configurations, the type saw prolific use by civil operators.<ref name = "bruce 65 9"/>

Early air services between [[London]], [[Paris]] and [[Amsterdam]] were operated by a fleet of DH.9s owned by [[Aircraft Transport and Travel]]. A number of DH9s were converted into [[floatplane]]s and saw use in [[India]], [[Bolivia]] and [[Rhodesia]].<ref name = "bruce 65 9 10">Bruce 1965, pp. 9-10.</ref> Several aircraft were reconfigured to serve as [[trainer aircraft]], being refitted with [[Armstrong Siddeley Jaguar]] engines and rubber undercarriages; designated as DH.9Js, the last of these were withdrawn and scrapped in 1936.<ref name = "bruce 65 10">Bruce 1965, p. 10.</ref>

A number of different DH.9 conversion programmes for civil use were carried out, both by Airco and its successor, the [[de Havilland|de Havilland Aircraft Company]], and by other third party companies, such as the [[ADC Aircraft|Aircraft Disposal Company]].<ref name="Jackson civilp50-52">Jackson 1973, pp. 50-52.</ref> Some radial powered DH.9Js continued in civil use until 1936.<ref name="Jackson civilp56">Jackson 1973, p. 56.</ref> One DH.9 was transported to Japan during the [[Sempill Mission]].<ref name = "Sturtivant 99p265">Sturtivant 1999, p. 265.</ref>  A large number of DH.9s were also apparently exported to China according to the [[ADC Aircraft|Aircraft Disposal Company]].<ref name = "Sturtivant 99p261">Sturtivant 1999, p. 261.</ref>

==Variants==
*'''DH.9''' – Revised version of the [[Airco DH.4|DH.4]] with the pilot and observer/gunner placed closer together (3,024 production aircraft built with others built in Belgium and Spain).
*'''[[Airco DH.9A|DH.9A]]''' – (also referred to as the '''Nine-Ack''') was designed for [[Airco]] by [[Westland Aircraft]] to take advantage of the {{cvt|400|hp}} American [[Liberty L-12]] engine. Apart from the new engine and slightly larger wings it was identical to the DH.9. Initially it was hoped to quickly replace the DH.9 with the new version, but the shortage of Liberty engines available to the RAF limited the new type's service in the First World War, and it is best known as a standard type in the postwar RAF, serving as a general purpose aircraft for several years. 2,300 DH.9As were built by ten different British companies.
*'''DH.9B''' – Conversions for civilian use as three-seaters (one pilot and two passengers)
*'''[[Airco DH.9C|DH.9C]]''' – Conversions for civilian use as four-seaters (one pilot and three passengers)
*'''DH.9J''' – Modernised and re-engined conversions using the {{cvt|385|hp}} [[Armstrong Siddeley Jaguar]] III [[radial engine]]. Used by the De Havilland School of Flying.
[[File:HP 17.png|thumb|Handley Page H.P. 17 showing slots]]
*'''DH.9J M'pala I''' – Re-engined conversions carried out by the [[South African Air Force]]. Powered by a {{cvt|450|hp}} [[Bristol Jupiter]] VI radial piston engine.
*'''M'pala II''' – Re-engined conversions carried out by the South African Air Force, powered by a {{cvt|480|hp}} Bristol Jupiter VIII radial piston engine.
*'''Mantis''' – Re-engined conversions carried out by the South African Air Force, powered by a {{cvt|200|hp}} [[Wolseley Viper]] piston engine.
*'''Handley Page HP.17''' – A DH.9 experimentally fitted with slotted wings, tested 1920–1.<ref name="Barnes Handleyp211-213">Barnes 1976, pp. 211–213.</ref>
*'''USD-9/9A''' – DH.9s manufactured in the United States by the [[US Army]]'s [[Engineering Division]] and [[Dayton-Wright Airplane Co|Dayton-Wright]]. (1,415 ordered, only four built)<ref>{{cite book|url=http://contrails.iit.edu/history/Huffman/H-part06.pdf |title=From Huffman Prairie to the Moon, The History of Wright-Patterson Air force Base |number=Part 6 |pages=184–186 |quote=Plans called for the Curtiss Aeroplane and Moto Corporation of Buffalo, New York, to manufacture 4,000 USD-9As. The order was cancelled, however, when Allied victories in France during the summer of 1918 forecast Germany's ultimate defeat...at least four USD-9A airplanes were manufactured at McCook, but none were built by a contractor. |publisher=WADC/WADD Digital Collection at the Galvin Library, IIT |year=1986 |isbn=978-0160022043 |url-status=dead |archive-url=https://web.archive.org/web/20160220132202/http://contrails.iit.edu/history/Huffman/H-part06.pdf |archive-date=20 February 2016 }}</ref>

== Operators ==
===Military operators===
{{acopmap|DH 9|DH.9 operators}}
;{{flag|Afghanistan|1919}}
*[[Afghan Air Force]] – 18 aircraft, including 16 built by [[Duks Aircraft Works]], acquired from 1924.
;{{AUS}}
*[[Royal Australian Air Force]] – One used by the RAAF from 1920 to 1929.
**No. 1 Flying Training School RAAF
;{{BEL}}
*[[Belgian Air Force]] – 18 aircraft.<ref name="Bruce ptII p423">Bruce 13 April 1956, p. 423.</ref>
;{{flag|Canada|1921}}
*[[Canadian Air Force (1918–1920)|Canadian Air Force]]
;{{BOL}}
*[[Bolivian Air Force]]
;{{CHL}}
*[[Chilean Air Force]] – Received 20.<ref name="Jackson DHp100"/>
;{{EST}}
*[[Estonian Air Force]] operated 13 from 1919 to 1933 .<ref>Gerdessen 1982, p. 76.</ref>
;{{flag|India|British}}
(Part of [[Imperial Gift]])
[[File:Greek aircraft during the Greco-Turkish War.jpg|thumb|Greek DH-9]]
;{{flag|Greece|old}}
*[[Hellenic Naval Air Service|Royal Hellenic Naval Air Service]]<ref name="Bruce pt II p425">Bruce 13 April 1956, p. 425.</ref>
;{{flag|Kingdom of Hejaz}}
*[[Hejaz Air Force]] – The Kingdom of Hejaz received 9 DH.9s and 2 DH.9Cs between 1921 and 1924. Five remained in existence (although not airworthy) in 1932.<ref name="AE119 p39-2">Andersson ''Air Enthusiast'' July/August 2004, pp. 39–42.</ref>
;{{IRL}}
*Irish Air Service
*[[Irish Air Corps]]
;{{LAT}}
*[[Latvian Air Force]]
;{{NLD}}
*[[Royal Netherlands East Indies Army Air Force]] – operated 36, some of which were re-engined with [[Pratt & Whitney Wasp]] [[radial engine]] withdrawn in 1934.<ref name="Bruce pt II p425"/>
;{{NZL}}
*[[Royal New Zealand Air Force]] – Three Airco DH.9s in service with the [[New Zealand Permanent Air Force]] from 1923 to 1929 as advanced training aircraft.
;{{flag|Paraguay}}
*[[Paraguayan Air Force]]
;{{PER}}
*[[Peruvian Air Force]]
;{{POL}}
*[[Polish Air Force]] – 20 received in 1920, used during the [[Polish-Soviet war]], until 1929.<ref>Kopański, Tomasz Jan. ''Samoloty brytyjskie w lotnictwie polskim 1918–1930'' (British aircraft in the Polish air force 1918–1930). Bellona, Warsaw. 2001, {{ISBN|83-11-09315-6}}, pp. 55–62. (in Polish)</ref>
;{{flag|Romania}}
*[[Royal Romanian Air Force]]
;{{flagicon|Spain|1785}} [[Kingdom of Spain]]
*[[Spanish Air Force]]
;{{flag|South Africa|1928}}
*[[South African Air Force]] – Part of the [[Imperial Gift]]. Some locally modified with Jupiter engines and named '''Mpala'''.
;{{USSR}}
*[[Soviet Air Force]]
;{{SUI}}
*[[Swiss Air Force]]
[[File:De Havilland D.H.9 Ganimet.jpg|thumb|Turkish DH-9]]
;{{TUR}}
*[[Turkish Air Force]] – four aircraft, in service from 1921 to 1924.
;{{UK}}
*[[Royal Flying Corps]]
*[[Royal Naval Air Service]]
*[[Royal Air Force]]
;{{flag|United States|1912}}
*[[American Expeditionary Force]]
*[[United States Marine Corps]]
;{{flag|Uruguay}}
*[[Uruguayan Air Force]]

===Civil operators===
;{{AUS}}
*[[Qantas]]
;{{BEL}}
*[[Sabena]]
*[[SNETA]]
;{{DEN}}
*[[Det Danske Luftfartselskab]]
;{{NLD}}
*[[KLM]]
;{{flag|Romania}}
*[[TAROM|SNNA]]
;{{flagicon|Spain|1785}} [[Kingdom of Spain]]
*Cia Espanola del Trafico Aereo
;{{UK}}
*[[Aircraft Transport and Travel]]
*[[Handley Page Transport]]
; [[File:Flag of Bikaner.svg|20px]] [[Bikaner State]]
* [[History of Bikaner#Ganga Singh|Maharaja Ganga Singh]]

==Surviving aircraft==
[[File:DH.9 F1258 LeB 05.07R.jpg|thumb|DH.9 ''F1258'' at the [[Musée de l'Air et de l'Espace]], Paris Le Bourget]]

Of the thousands of DH.9s built, only a few survived to be preserved:
* ''F1258'' is displayed at the ''Musée de l'Air et de l'Espace'' in [[Paris]],<ref>[https://archive.today/20120527035029/http://www.mae.org/index.php?id=378 "DH.9."] ''Musée de l'Air et de l'Espace''. Retrieved: 11 April 2008.</ref>
* An original DH.9 is displayed without serial number at the [[South African National Museum of Military History]].<ref>Blake, Arthur.[http://rapidttp.com/milhist/vol016ab.html "Colours in the Sky."] ''Military History Journal'', Vol 1, No 6. June 1970. The South African Military History Society. Retrieved: 11 April 2008.</ref> This DH.9 flew with the South African Air Force after World War I, then was operated as a civilian aircraft as ZS-AOI, before returning to the SAAF.
* ''G-EAQM'' (original RAF serial F1278) was the first single-engined aircraft to fly from the United Kingdom to Australia and is preserved at the [[Australian War Memorial]] in [[Canberra]].<ref name="Jackson DHp125">Jackson 1987, p. 125.</ref><ref>[http://cas.awm.gov.au/photograph/P02270.029 "AWM Collection Record: P02270.029."] {{Webarchive|url=https://web.archive.org/web/20110928054753/http://cas.awm.gov.au/photograph/P02270.029 |date=28 September 2011 }} ''Australian War Memorial'', Retrieved: 11 April 2008.</ref>

In 2000, the remains of three DH.9s were discovered in India and two were retrieved for restoration in the UK.<ref>[http://news.bbc.co.uk/1/hi/in_pictures/6577629.stm "In pictures: 'Elephant stable' bomber."] ''BBC News'', 21 April 2007. Retrieved: 11 April 2008.</ref> Of these,
* ''D5649'' was restored and is displayed at the [[Imperial War Museum]], Duxford.<ref>{{Cite web|url=https://www.iwm.org.uk/collections/item/object/70000411|title = Airco de Havilland DH-9}}</ref>
* ''E8894/G-CDLI'' was restored to airworthy condition and is operated as a [[warbird]] by the Historic Aircraft Company in England.<ref>{{Cite web|url=http://www.historicaircraftcollection.ltd.uk/dh9.html|title = Hac: Dh9}}</ref>
* The third was retained in India and restored to a somewhat less-than-faithful condition for display at [[Junargh Fort]] in the city of [[Bikaner]], [[Rajasthan]].<ref>{{Cite web|url=https://www.flickr.com/photos/asienman/11069637676|title = India - Rajasthan - Bikaner - Junagarh Fort - Museum - de Havilland DH9 - 75|date = 10 April 2012}}</ref>

==Specifications (DH.9 (Puma Engine))==
[[File:Airco de Havilland DH.9 dwg.jpg|thumb|Airco DH.9 drawing]]
{{Aircraft specs
|ref=''The British Bomber since 1914'',<ref name="masonp86">Mason 1994, p. 86.</ref> ''Aircraft Profile No. 62: The de Havilland D.H.9''<ref name = "bruce 65 10 12">Bruce 1965, pp. 10, 12.</ref>
|prime units?=imp<!-- imp for US and UK pre-metrification aircraft, met(ric) for all others. You MUST choose a format, or no specifications will show -->
<!-- General characteristics -->
|genhide=
|crew=two
|length m=
|length ft=30
|length in=5
|length note=
|span m=
|span ft=42
|span in=4+5/8
|span note=
|height m=
|height ft=11
|height in=3+1/2
|height note=
|wing area sqm=
|wing area sqft=434
|wing area note=
|airfoil=RAF-16<!--<ref>{{cite web |last1=Lednicer |first1=David |title=The Incomplete Guide to Airfoil Usage |url=https://m-selig.ae.illinois.edu/ads/aircraft.html |website=m-selig.ae.illinois.edu |access-date=16 April 2019}}</ref>-->
|empty weight kg=
|empty weight lb=2360
|empty weight note=
|gross weight kg=
|gross weight lb=3790
|gross weight note=
|fuel capacity=
|more general=
<!-- Powerplant -->
|eng1 number=1
|eng1 name=[[Armstrong Siddeley Puma]]
|eng1 type=6 cylinder inline piston engine
|eng1 kw= <!-- prop engines -->
|eng1 hp=230 <!-- prop engines -->
|eng1 note=
<!-- Performance -->
|perfhide=
|max speed kmh= 
|max speed mph=113 
|max speed kts= 
|max speed note=
|cruise speed kmh=
|cruise speed mph=
|cruise speed kts=
|cruise speed note=
|stall speed kmh=
|stall speed mph=
|stall speed kts=
|stall speed note=
|range km=
|range miles=
|range nmi=
|range note=
|endurance=4+1/2 hours
|ceiling m=
|ceiling ft=15500
|ceiling note=
|climb rate ms=
|climb rate ftmin=
|climb rate note=
|time to altitude=18 min 30 sec to {{cvt|10000|ft}}
|more performance=
<!-- Armament -->
|guns=Forward firing {{cvt|.303|in}} [[Vickers machine gun]] and 1 or 2 × {{cvt|.303|in}} [[Lewis gun]]s on [[scarff ring]] in rear cockpit
|bombs=Up to {{cvt|460|lb}} bombs
}}

==See also==
{{aircontent
<!-- include as many lines are appropriate. additional lines/entries with carriage return. -->
|related=*[[Airco DH.4]]
*[[Airco DH.9A]]
|similar aircraft=<!-- similar or comparable aircraft -->
*[[Breguet 14]]
|lists=<!-- related lists -->
|see also=<!-- other relevant information -->
}}

==References==

===Notes===
{{Reflist}}

===Bibliography===
* Andersson, Lennart. "Wings Over the Desert: Aviation on the Arabian Peninsula: Part One Saudi Arabia". ''[[Air Enthusiast]]'', No. 112, July/August 2004. pp.&nbsp;39–43. ISSN 0143-5450.
* Barnes, C.H. ''Handley Page Aircraft since 1907''. London:Putnam, 1976. {{ISBN|0-370-00030-7}}.
* Bruce, J. M. "Aircraft Profile No. 62: The de Havilland D.H.9". ''Profile Publications Ltd'', 1965.
* Bruce, J.M. "[http://www.flightglobal.com/pdfarchive/view/1956/1956%20-%200387.html The De Havilland D.H.9: Historic Military Aircraft: No. 12, Part I]". ''[[Flight International|Flight]]'', 6 April 1956. Pages 385–388, 392.
* Bruce, J.M. "[http://www.flightglobal.com/pdfarchive/view/1956/1956%20-%200422.html The De Havilland D.H.9: Historic Military Aircraft: No. 12, Part II]". ''[[Flight International|Flight]]'', 13 April 1956. Pages 422–426.
*{{cite magazine|last=Cooksley|first=Peter|title=Erratic Their Course|magazine=[[Air Enthusiast]] |date=Spring 1994|issue=53 |pages=53–59 |issn=0143-5450}}
* Gerdessen, Frederik. "Estonian Air Power 1918 – 1945". ''[[Air Enthusiast]]'', No. 18, April – July 1982. pp.&nbsp;61–76. {{ISSN|0143-5450}}.
* Jackson, A.J. ''British Civil Aircraft since 1919 Volume 2''. London:Putnam, Second edition 1973. {{ISBN|0-370-10010-7}}.
* Jackson, A.J. ''De Havilland Aircraft since 1909''. London: Putnam, Third edition 1987. {{ISBN|0-85177-802-X}}.
* London, Pete. "Air War Over Ireland". ''[[Aeroplane Monthly|Aeroplane]]'', October 2015, Vol. 43, No. 10. pp.&nbsp;32–37. {{ISSN|0143-7240}}
*{{cite journal |last1=Klaauw|first1=Bart van der|title=Unexpected Windfalls: Accidentally or Deliberately, More than 100 Aircraft 'arrived' in Dutch Territory During the Great War |journal=Air Enthusiast |date=March–April 1999 |issue=80 |pages=54–59 |issn=0143-5450}}
* Mason, Francis K. ''The British Bomber Since 1914''. London: Putnam Aeronautical Books, 1994. {{ISBN|0-85177-861-5}}.
* Sturtivant, R. Page, G. "The DH.4/DH.9 File". Kent: Air-Britain (Historians) Ltd, 1999. {{ISBN|0-85130-274-2}}.
* Thomas, Andrew. "In the Footsteps of Daedulus: Early Greek Naval Aviation". ''Air Enthusiast'', No. 94, July–August 2001, pp.&nbsp;8–9. {{ISSN|0143-5450}}
*{{cite journal |last1=Wauthy|first1=Jean-Luc|last2=de Neve|first2=Florian|name-list-style=amp|title=Les aéronefs de la Force Aérienne Belge, deuxième partie 1919–1935|journal=Le Fana de l'Aviation  |date=June 1995 |issue=305 |pages=28–33 |issn=0757-4169|language=fr|trans-title=Aircraft of the Belgian Air Force}}
* Winchester, Jim, ed. ''Bombers of the 20th Century''. London: Airlife Publishing Ltd., 2003. {{ISBN|1-84037-386-5}}.

==External links==
{{Commons category}}
*[https://web.archive.org/web/20070428004017/http://www.airspaceduxford.org.uk/html/infocus/infocus_news11.htm DH9 at Imperial War Museum, Duxford]
*[https://web.archive.org/web/20070930183025/http://www.britishaircraft.co.uk/aircraftpage.php?ID=572 AAirco D.H.9] – British Aircraft Directory

{{De Havilland aircraft}}
{{Handley Page aircraft}}
{{Engineering Division aircraft}}
{{ADF aircraft designations}}
{{Authority control}}

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