Colloquially known as the "Ninak" (from the phonetic alphabet treatment of designation "nine-A"), it served on in large numbers for the Royal Air Force following the end of the war, both at home and overseas, where it was used for colonial policing in the Middle East, finally being retired in 1931.[2] The prototype proved successful, with the first Liberty-engined DH.9A flying on 19 April 1918, and deliveries to the Royal Air Force starting in June.As it was decided that the DH.9A would be a standard type in the postwar RAF, the majority of outstanding orders were fulfilled, with 1,730 being built under the wartime contracts before production ceased in 1919.In 1921, test pilot Lt. Harold R. Harris made the world's first high-altitude flight in a pressurised aircraft in the USD-9A at McCook Field in Dayton, Ohio.The United States Marine Corps Northern Bombing Group received at least 53 DH-9As, and commenced operations in September 1918.Despite this the aircraft served successfully, with the Liberty engine being picked out for particular praise for its reliability ("as good as any Rolls Royce") in such harsh conditions.At home, the DH.9A continued on in regular RAF service until 1930, also forming the initial equipment of the Royal Auxiliary Air Force (RAuxAF).The squadron began flying bombing missions in September 1918, and on the 25th, the crew of F1010 claimed the destruction of a German Fokker D.VII fighter.The aircraft's fourth and final combat mission was on 5 October when either flak damage or engine trouble forced a landing behind German lines.
DH.9A number
F1010
at the RAF Museum, London in 2010