de Havilland DH.51
De Havilland designed the DH.51 as an economical touring biplane, based on the 90 hp (67 kW) RAF 1A engine which was available from war-surplus stocks.As it would have taken at least ten hours of flight testing to certify it with a single-ignition system, de Havilland decided to re-engine the aircraft instead.The aircraft was fitted with an ADC Airdisco Air-cooled V8 piston engine, which considerably improved performance but was no longer cheap to operate.It was then put on the UK register as G-EBIR and passed to The Shuttleworth Collection in Bedfordshire where it remains in an airworthy condition to this day.The third aircraft (registered G-EBIR and named Miss Kenya; built in 1925) remains airworthy with the Shuttleworth Collection, Old Warden, England and can be seen at flying events throughout the summer months.