The Nakajima Ki-49 series known as the Donryu (Storm Dragon) was designed to supercede the Mitsubishi Ki-21 bomber, which was then just entering Japanese Army service, and the prototype (c/n 4901) was first flown in August 1939.

The DH.71 Tiger Moth was built in secrecy at Stag Lane in 1927 for high-speed research, mainly to act as a flying test-bed for a new series of engines being designed by Major F B Halford