Étienne Edmond Oehmichen (1884-1955) was a French engineer and helicopter designer. He was also something of an innovator, patenting the first electric stroboscope (instrument used to make a cyclically moving object appear to be slow-moving, or stationary) and designing a camera that shoot 1,000 frames per second. Oehmichen was also a biologist and dealt with the principle function of insect wings, especially dragonflies, and this may explain his forays into flying.
His first successful flight with his experimental helicopter was on 18 February 1921, piloted by Oehmichen. As you can see from the image, this was not a passenger craft! All the rotors went in the same direction, limiting its flying capabilities.
On 11 November 1922, ‘Oehmichen No.2’ took to the air, an improved helicopter featuring small vertically mounted rotors which rotated in the opposite direction from the large lifting rotors, creating probably the first reliable flying helicopter capable of carrying a person. This work later led to the development of the tail rotor.
On 14 April 1923 he broke the existing record for helicopter flight with a flight of 358 m. 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 around 7 minutes and 40 seconds. Also in 1924 he carried his first two passengers.
In 1921 Oehmichen invented and tested a type of blimp he called the “Hélicostat” that was controlled by four movable propellers, which could hover, take off, and land without ground crew. The words given meaning is “heavier than air”. The No.1 was effectively a helicopter on which an elongated balloon (140 m³) was placed perpendicular to the frame and inflated with hydrogen to ensure stability. While the machine, equipped with two propellers sustentatrices, weighed 336 kg with the driver. The machine went through a number of manifestations (7) until 1935.
Such machines were the forerunner of our modern helicopters, showing how far we have come in a relatively short time.
He worked at the Collège de France in Paris for 30 years until his retirement.