The Airco DH.9 also known after 1920 as the de Havilland DH.9, it was a British single-engine biplane bomber developed and deployed during the First World War.
Upon entering service, the DH.9’s performance was found to be unsatisfactory.
The Adriatic 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.
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.
Revised version of the DH.4 with the pilot and observer/gunner placed closer together.
Was designed for Airco by Westland Aircraft to take advantage of the 400 hp (300 kW) 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 post-war RAF, serving as a general purpose aircraft for several years.
2,300 DH.9As were built by ten different British companies.
Modernised and re-engine 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-engine conversions carried out by the South African Air Force.
Powered by a 450 hp (340 kW) Bristol Jupiter VI radial piston engine.
Re-engined conversions carried out by the South African Air Force, powered by a 480 hp (360 kW) Bristol Jupiter VIII radial piston engine.
Re-engine conversions carried out by the South African Air Force, powered by a 200 hp (150 kW) Wolseley Viper piston engine.
Handley Page HP.17
A DH.9 experimentally fitted with slotted wings, tested 1920–1.
DH.9s manufactured in the United States by the US Army’s Engineering Division and Dayton-Wright.