Prof. Heinrich Focke and engineer Gerd Achgelis started the design for this helicopter in 1932. The airframe was based on that of a well-tried training aircraft. A single engine drove twin rotors, to the left and right of the fuselage. Only a prototype was produced (by Focke-Wulf). In 1936 it was demonstrated by Hanna Reitsch in Berlin, Germany. It achieved an altitude of nearly 8000 feet, a speed of 76 mph a flight duration of 80 minutes and a distance of over 50 miles.