Airco DH.9
1917 bomber aircraft family
The Airco DH.9 (from 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 First World War.
The DH.9 was a development of Airco's earlier successful DH.4, with which it shared many components. These were mated to an all-new fuselage and used the Beardmore Halford Pullinger 230 hp (170 kW) 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 less 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. The redesigned 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 British Cabinet accepted the recommendation, with the intention that the majority of the new squadrons were to be equipped with bombers.
The public source identifies “Airco DH.9” as 1917 bomber aircraft family. This brief keeps that definition visible, then builds a research path around Airco, bomber and aircraft.
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The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Jul 26, 2026. The linked authority identifier is Q163488. The Library of Congress control number is sh2010007486. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1920 and 1917.
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This entry incorporates text from “Airco DH.9” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.