Juan de la Cierva

From Wikipedia, the free encyclopedia

Cierva's first successful autogyro

Juan de la Cierva (21 September 1895 – 19 December 1936) was a Spanish aeronautical engineer and pilot. His most famous accomplishment was the invention in 1919 of the Autogiro, a type of aircraft that later came to called an autogyro. After four years of experimentation, la Cierva developed the articulated rotor which resulted in the world's first successful flight of a stable rotary-wing aircraft in 1923.

De la Cierva was born in Murcia, Spain to a wealthy family. After several successful experiments with aviation as a boy, he eventually earned a civil engineering degree. He moved to England in 1925 where with the support of Scottish industrialist James G. Weir, he established the Cierva Autogiro Company.

During the Spanish Civil War, De la Cierva supported the forces of Francisco Franco. He died in an airliner accident near London at the age of 41.

Technology developed for the Autogiro was utilized by experimenters in the development of the helicopter, the first fully successful example of which, the FA-61, was flown in 1936 by Cierva Autogiro Company licensee Focke-Achgelis. The Autogiro also led directly the Cierva C.38 Gyrodyne, which utilized a powered rotor for hovering and low speed flight, and a side-mounted propeller for torque correction and propulsion in cruise flight. As airspeed increased, propellor power increased while rotor power automatically decreased which reduced rotor collective pitch to autorotative angle with the rotor remaining parallel to the flightpath. As airspeed reduced, propeller power decreased while rotor power automatically increased which increased rotor collective pitch to non-autorotative angles. The Fairey Gyrodyne, first flown in 1948, established the superiority of this configuration over that of the helicopter, which De la Cierva consistently rejected as too mechanically complicated, even though he agreed with the requirement for hovering performance.