This engine was manufactured by the de Havilland Aircraft Company, Ltd. of Middlesex, England, and designed by Frank B. Halford, a famous and successful British automotive and aircraft engine designer whose career lasted most of the first half of the twentieth century. During his career in aviation, he worked as freelance designer, as well as for de Havilland and Napier.
The Gipsy series of aircraft engines originated in the late-1920s, beginning with 4-cylinder models. Although designed before World War II, production of the Gipsy Queen Q70 had to wait until the end of the war. The Gipsy Queen 70 was a direct descendant of the 1930s-era Gipsy Six, and was the first geared and supercharged in-line, six-cylinder engine put into production. The first of the Queen 70 engines flew in 1945 in the prototype de Havilland Dove. The Q70 Mk II powered the de Havilland D.H. 104 Dove Series 5 commuter and executive aircraft.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.