Étienne Oehmichen
Étienne Edmond Œhmichen (; 15 October 1884, in Châlons-sur-Marne Châlons-en-Champagne – 10 July 1955, in Paris) was a French engineer and helicopter designer. Biography. Œhmichen studied at École Centrale Paris. He patented the first electric stroboscope in 1917, building at the same time a camera capable of shooting 1,000 frames per second. His first successful flight with a helicopter took place on 18 February 1921. On 11 November 1922, he first flew 'Oehmichen No.2', an improved helicopter featuring small vertically mounted rotors which rotated in the opposite direction from the large lifting rotors, probably creating the  first reliable flying helicopter capable of carrying a person. This work later led to the development of the tail rotor. On 14 April 1924, he broke the existing record for helicopter flight with a flight of 360 m and 525 m a few days later, just before being surpassed by Raúl Pateras Pescara. On 4 May 1924, he won a prize of 90,000 French Francs for the first successful closed circuit helicopter flight following a triangular trajectory with a length of approximately one km, a flight which took approximately 7 minutes and 40 seconds. The same year, he made a  flight with two passengers. In 1931, Œhmichen invented and tested a type of blimp he called the "Hélicostat", controlled by four movable propellers, which could hover, take off, and land without ground crew. Œhmichen was also a biologist and studied insect wing function, especially in dragonflies. He worked at the Collège de France in Paris for 30 years until his retirement. Publications. His writing and photographs contained observations of the bird and insect flight.