Raoul Hafner, (1905–1980) FEng, FRAes, was an Austrian-born and educated British helicopter pioneer and engineer. He made important contributions to the British aerospace industry, particularly in the development of helicopters.
In his spare time he developed the Revoplane 1 and Hafner Revoplane 2, with finance from Scottish cotton millionaire Major Jack Coates.
After learning of the work of the Spanish pioneer Juan de la Cierva, Hafner and his business partner Bruno Nagler moved from Austria to England to design an autogyro incorporating the principles of the R1 and R2.
Hafner parted company with Nagler and concentrated on gyroplane design. In 1934 his own company, the ARIII Construction (Hafner Gyroplane) Co, embarked on the design of the ARIII Gyroplane. See 1937 'Flight' magazine article.
In 1938 he joined Pobjoy-Short at Rochester. In 1940 he was briefly interned as an enemy alien.
He developed the Hafner Rotachute and the Rotabuggy, a rotor-equipped jeep.
After the war Hafner and some of his team joined the Bristol Aeroplane Co. He became their Chief Helicopter Designer. Bristol produced the Sycamore helicopter, and, later, the large Belvedere helicopter.
In 1960 Westland Aircraft took over Bristol's helicopter business, and Hafner was appointed Technical Director.
For more information, see Wikipedia entry.