Airco DH.9

The Airco DH.9 (from de Havilland 9) - also known after 1920 as the de Havilland DH.9 - was 

DH.9
Airco DH.9
Role	Bomber
Manufacturer	Airco
Designer	Geoffrey de Havilland
First flight	July 1917
Introduction	1917
Retired	1920
Primary users	Royal Air Force RNAS, RFC.
Number built	4,091
Variants	Airco DH.9A Airco DH.9C Westland Walrus

a British bomber used in the First World War. A single-engined biplane, it was a development of Airco's earlier, highly successful DH.4 and was ordered in very large numbers for Britain's Royal Flying Corps and Royal Air Force.

Its engine was unreliable, and failed to provide the expected power, giving the DH.9 poorer performance than the aircraft it was meant to replace, and resulting in heavy losses, particularly over the Western Front. The subsequently-developed DH.9A had a more powerful and reliable American Liberty L-12 engine.

Design and development

The DH.9 was designed by de Havilland  for the Aircraft Manufacturing Company  in 1916 as a successor to the DH.4 . It used the wings and tail unit  of the DH.4 but had a new fuselage . This enabled the pilot  to sit closer to the gunner/observer  and away from the engine  and fuel tank. The other major change from the DH.4 was the choice of the promising new BHP/Galloway  Adriatic engine, which was predicted to produce 300 hp (224 kW) and so give the new aircraft an adequate performance to match enemy fighters.^[1]

By this time, as a result of attacks by German bombers on London, the decision was made to almost double the size of the Royal Flying Corps , with most of the new squadrons planned to be equipped with bombers .^[2] Based on the performance estimates for the DH.9 (which were 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, massive orders (4,630 aircraft) were placed.

The prototype (a converted DH.4) first flew at Hendon  in July 1917.^[1] Unfortunately, the BHP  engine proved unable to reliably deliver its expected power, with the engine being de-rated to 230 hp (186 kW) in order to improve reliability. This 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. This 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.

While attempts were made to provide the DH.9 with an adequate engine, with aircraft being fitted with the Siddeley Puma , a lightened and supposedly more powerful version of the BHP, with the Fiat A12 engine and with a 430 hp (321 kW) Napier Lion  engine, these were generally unsuccessful (although the Lion engined aircraft did set a World Altitude Record  of 30,500 ft (13,900 m) on 2 January 1919^[3]) and it required redesign into the DH.9A to transform the aircraft.

Operational history

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 were made in November 1917 to 108 Squadron  RFC  and it first went into combat over France in March 1918 with 6 Squadron , and by July 1918 nine squadrons operational over the Western Front were using the type.

The DH.9's performance in action over the Western Front was a disaster, with heavy losses incurred, both due to its poor performance and to engine failures, despite the prior de-rating of its engine. Between May and November 1918, two squadrons on the Western Front (Nos. 99  and 104 ) lost 54 shot down, and another 94 written off in accidents.^[4] Nevertheless, on 23 August 1918 a DH9 flown by Lieutenant Arthur Rowe Spurling  of 49 Squadron, with his observer, Sergeant Frank Bell , single-handedly attacked thirty Fokker D.VII  fighters, downing five of them.^{[citation needed]}Captain John Stevenson Stubbs  managed 11 aerial victories in a DH9, including the highly unusual feat of balloon busting  with one.^[5]

The DH.9 was also more successful against the Turkish forces in the Middle East , where they faced less opposition, and it was used extensively for coastal patrols, to try to deter the operations of U-boats .

Following the end of the First World War, DH.9s operated by 47 Squadron and 221 Squadron were sent to southern Russia in 1919 in support of the White Russian Army of General Denikin during the Russian Civil War.^[6] The last combat use by the RAF was in support of the final campaign against Mohammed Abdullah Hassan(known by the British as the "Mad Mullah") in Somalia during January—February 1920.^[6] Surprisingly, production was allowed to continue after the end of the war into 1919, with the DH.9 finally going out of service with the RAF in 1920.^[7]

Following the end of the First World War, large number of surplus DH.9s became available at low prices and the type was widely exported (including aircraft donated to Commonwealth nations as part of the Imperial Gift programme.^[3]

The South African Air Force received 48 DH.9s, and used them extensively, using them against the Rand Revolt in 1922. Several South African aircraft were re-engined with Bristol Jupiter radial engines as the M'pala, serving until 1937.^[8]

Civilian use

Because of the large number of surplus DH.9s available after the war many were used by air transport companies. They provided a useful load carrying capability and were cheap. Early air services between London, Paris and Amsterdam were operated by DH.9s owned by Aircraft Transport and Travel. A number of different conversions for civil use were carried out, both by Airco and its successor the de Havilland Aircraft Company and by other companies, such as the Aircraft Disposal Company.^[9] Some radial powered DH.9Js continued in use until 1936.^[10]

Variants

Handley Page H.P. 17 showing slots

• DH.9 - Revised version of the DH.4 with the pilot and observer/gunner placed closer together (3,024 production aircraft built with others built in Belgium and Spain).
• DH.9A - (also referred to as the Nine-Ack) was designed for Airco by Westland Aircraft to take advantage of the 400 hp (298 kW) AmericanLiberty 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)
• DH.9C - Conversions for civilian use as four-seaters (one pilot and three passengers)
• DH.9J - Modernised and re-engined conversions using the 385 hp (287 kW)Armstrong Siddeley Jaguar III radial engine. Used by the De Havilland School of Flying.
• DH.9J M'pala I - Re-engined conversions carried out by the South African Air Force. Powered by a 450 hp (336 kW) Bristol Jupiter VI radial piston engine.
• M'pala II - Re-engined conversions carried out by the South African Air Force, powered by a 480 hp (358 kW) Bristol Jupiter VIII radial piston engine.
• Mantis - Re-engined conversions carried out by the South African Air Force, powered by a 200 hp (149 kW) Wolseley Viper piston engine.
• Handley Page HP.17 - A DH.9 experimentally fitted with slotted wings^[11]
• USD-9/9A - DH.9s manufactured in the United States by the US Army'sEngineering Division and Dayton-Wright. (1,415 ordered, only 4 built)^[12]

Operators

Military operators

Afghanistan

• 18 aircraft, including 16 built by Duks Aircraft Works, were acquired from 1924 by the Afghan Air Force.

Australia

• Royal Australian Air Force - Only one DH.9 (RAAF serialA1-28) was ever used by the RAAF from 1920 to 1929.
  • No. 1 Flying Training School RAAF

Belgium

• Belgian Air Force - 18 aircraft.^[13]

Canada

• Canadian Air Force

Bolivia

• Bolivian Air Force

Chile

• Chilean Air Force - Received 20 DH.9s.^[3]

Estonia

• Estonian Air Force operated 13 DH.9s from 1919 to 1933 .^[14]

India

(Part of Imperial Gift)

Greece

• Royal Hellenic Naval Air Service^[15]

Kingdom of Hejaz

The Kingdom of Hejaz received 11 DH.9s (including 2 DH.9Cs) between 1921 and 1924. Five remained in existence (although not airworthy) in 1932.^[16]

Ireland

• Irish Air Service
• Irish Air Corps

Latvia

• Latvian Air Force

Netherlands

• Royal Netherlands East Indies Army Air Force - Operated 36 DH.9s, some of which were re-engined with Pratt & Whitney Wasp radial engine and remaining in service until 1934.^[15]

New Zealand

• Royal New Zealand Air Force - Three Airco DH.9s were in service with the New Zealand Permanent Air Force from 1923 to 1929. The DH.9s were used by theNZPAF as advanced training aircraft.

Paraguay

• Paraguayan Air Force

Peru

• Peruvian Air Force

Poland

• Polish Air Force - 20 DH.9 received in 1920, used during the Polish-Soviet war, until 1929.^[17]

Romania

• Royal Romanian Air Force

Kingdom of Spain

• Spanish Air Force

South Africa

• South African Air Force - Part of the Imperial Gift. Some were locally modified with Jupiter engines and named Mpala.

Soviet Union

• Soviet Air Force

Switzerland

• Swiss Air Force

Turkey

• Turkish Air Force - 4 aircraft, in service from 1921 to 1924.

United Kingdom

• Royal Flying Corps
• Royal Naval Air Service
• Royal Air Force

United States

• American Expeditionary Force
• United States Marine Corps

Uruguay

• Uruguayan Air Force

Civil operators

Australia

• Qantas

Belgium

• Sabena

Denmark

• Det Danske Luftfartselskab

Netherlands

• KLM

Romania

• SNNA

Kingdom of Spain

• Cia Espanola del Trafico Aereo

United Kingdom

• Aircraft Transport and Travel
• Handley Page Transport

Bikaner State

• Maharaja Ganga Singh

Survivors

DH.9 preserved at the Imperial War Museum Duxford

DH.9 F1258 displayed at the Musée de l'Air et de l'Espace, Paris Le Bourget

Of the thousands of DH.9s built, only a few have survived to be preserved. F1258 is displayed at theMusée de l'Air et de l'Espace in Paris,^[18] with a second DH.9 being preserved at the South African National Museum of Military History,^[19] while G-EAQM, the first single-engined aircraft to fly from the United Kingdom to Australia is preserved in theAustralian War Memorial at Canberra.^[20][21]

The remains of three DH.9s were discovered in India in 2000,^[22] one of which is displayed at theImperial War Museum Duxford, and another in the process of being restored to flying condition.^[23]

Specifications (D.H.9 (Puma Engine))

Data from The British Bomber since 1914^[7]

General characteristics

• Crew: 2
• Length: 30 ft 5 in (9.27 m)
• Wingspan: 42 ft 4⅝ in (12.92 m)
• Height: 11 ft 3½ in (3.44 m)
• Wing area: 434 ft² (40.3 m²)
• Empty weight: 2,360 lb (1,014 kg)
• Max. takeoff weight: 3,790 lb (1,723 kg)
• Powerplant: 1 × Armstrong Siddeley Puma piston engine, 230 hp (172 kW)

Performance

• Maximum speed: 98 kn (113 mph, 182 km/h)
• Endurance: 4½ hours
• Service ceiling: 15,500 ft (4,730 m)
  
• Climb to 10,000 ft: 18 min 30 sec

Armament

• Guns: Forward firing Vickers machine gun and 1 or 2 × Rear Lewis guns on scarff ring
• Bombs: Up to 460 lb (209 kg) bombs

See also

Related development

• Airco DH.4
• Airco DH.9A

Aircraft of comparable role, configuration and era

• Breguet 14

References

Notes

1. ^ Jump up to:^a b Jackson 1987, p.97.
2. Jump up^ Bruce 2 April 1956, p.387.
3. ^ Jump up to:^a b c Jackson 1987, p.100.
4. Jump up^ Mason 1994, p.84.
5. Jump up^ http://www.theaerodrome.com/aces/england/stubbs2.php Retrieved 1 May 2011.
6. ^ Jump up to:^a b Bruce 13 April 1956, p.424.
7. ^ Jump up to:^a b Mason 1994, p.86.
8. Jump up^ Jackson 1987, p.102.
9. Jump up^ Jackson 1973, p.50-52.
10. Jump up^ Jackson 1973, p.56.
11. Jump up^ Barnes 1976, p.211-213.
12. Jump up^ "From Huffman Prairie To The Moon, The History of Wright-Patterson Air force Base" (Part 6). WADC/WADD Digital Collection at the Galvin Library, IIT. 1986. pp. 184–186. ISBN 978-0160022043. "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."
13. Jump up^ Bruce 13 April 1956, p.423.
14. Jump up^ Gerdessen 1982, p.76
15. ^ Jump up to:^a b Bruce 13 April 1956, p.425.
16. Jump up^ Andersson Air Enthusiast July/August 2004, pp. 39–42.
17. Jump up^ 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, p.55-62 (in Polish)
18. Jump up^ DH.9. Musée de l'Air et de l'Espace. Retrieved 11 April 2008
19. Jump up^ Blake, Arthur."Colours in the Sky" Military History Journal - Vol 1 No 6, June 1970. The South African Military History Society. Retrieved 11 April 2008
20. Jump up^ Jackson 1987, p.125.
21. Jump up^ AWM Collection Record: P02270.029 Australian War Memorial. Retrieved 11 April 2008
22. Jump up^ In pictures: 'Elephant stable' bomber BBC.co.uk, 21 April 2007. Retrieved 11 April 2008
23. Jump up^ DH-9 Historic Aircraft Collection Ltd. Retrieved 11 April 2008

Bibliography

• Andersson, Lennart. "Wings Over the Desert: Aviation on the Arabian Peninsula: Part One Saudi Arabia". Air Enthusiast, No. 112, July/August 2004. pp. 39–43. ISSN 0143-5450.
• Barnes, C.H. Handley Page Aircraft since 1907. London:Putnam, 1976. ISBN 0-370-00030-7.
• Bruce, J.M. "The De Havilland D.H.9: Historic Military Aircraft: No. 12, Part I". Flight, 6 April 1956. Pages 385—388, 392.
• Bruce, J.M. "The De Havilland D.H.9: Historic Military Aircraft: No. 12, Part II". Flight, 13 April 1956. Pages 422—426.
• Gerdessen, F. "Estonian Air Power 1918 - 1945". Air Enthusiast No 18, April - July 1982. Pages 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.
• Mason, Francis K. The British Bomber Since 1914. London: Putnam Aeronautical Books, 1994. ISBN 0-85177-861-5.
• Winchester, Jim, ed. Bombers of the 20th Century. London: Airlife Publishing Ltd., 2003.ISBN 1-84037-386-5.