Airco DH.9A

The Airco DH.9A was a British single-engined light bomber designed and first used shortly before the end of the First World War. It was a development of the unsuccessful DH.9, with a strengthened structure and longer-span wings, and it replaced the under-powered and unreliable inline Siddeley Puma of the DH.9 with the American V-12 Liberty engine. Because Airco was busy developing the DH.10 Amiens, the detailed design was carried out by Westland Aircraft. The first prototype flew in March 1918 with a Rolls-Royce Eagle because no Liberty engines were yet available, and the first Liberty-engined aircraft flew on 19 April 1918. Colloquially known as the Ninak, it served in large numbers with the Royal Air Force after the war, including colonial policing in the Middle East, until it was retired in 1931. Over 2,400 examples of an unlicensed version, the Polikarpov R-1, were built in the Soviet Union.