History of the Autogyro
Juan de la Cierva, a Spanish engineer invented the first autogyro in 1919 as part of a design competition. Early flights revealed problems with the design that caused the aircraft to stall in flight. The first successful flight in this type of aircraft took place in Madrid in January 1923. This first autogyro was named the Autogiro and used an airplane fuselage with a forward mounted engine and propeller. It also had a rotor mounted on a mast, a horizontal and vertical stabilizer and flapping hinges that attached the rotor to the hub.
Cierva developed further autogyro designs with assistance from Spain’s Military Aviation. The c.6 made a record flight of 10 km in 1925. Following this accomplishment, he accepted a position in England to set up the Cierva Autogiro Company, which made Britain the centre of development of this type of aircraft. The rotor hub design was improved upon following a crash in 1927 caused by blade root failure. In the new design a drag hinge was added that worked in conjunction with the flapping hinge. An American industrialist, Harold Pitcairn, became interested in the designs and brought this idea to the US. The Pitcairn Autogiro Company became a manufacturer of the aircraft along with a company in Germany.
Throughout the following years, redesigns of the rotor were experimented with. In the early years it required a team of men to pull ropes attached to the rotor blades to start the spinning action. In 1930, the US affiliate came up with the design of a transmission to help start the blades. Because the autogyros lost control when flying at low altitudes and when landing, Cierva worked to come up with a design so that the pilot could tilt the rotor. This design was first used on the C.34 in 1934.
Autogyros did not receive the same amount of attention as helicopters, but during World War 11, Germany pioneered a smaller form of the aircraft to do aerial surveillance. These were towed by U-boats. The Japanese also developed reconnaissance autogyros, such as the Kayaba Ka-1. After the war, a Russian immigrant named Dr. Igor Benson, had the task of analyzing the German design, which led him to come up with his own design, which he submitted to the US Air Force. This became the X-25 and was used for flying unmanned target missions. The Benson Gyrocopter used the pusher configuration now common in this aircraft and has become a registered trademark for pusher configuration autogyros.