The next episode of our documentary series SPANISH GENIUSES is about a machine designed so it would not stall: if its engine stopped, it came down slowly, almost vertically. It is the autogiro, and its inventor was Juan de la Cierva, an engineer born in Murcia in 1895. Chapter 3, “Autogiro: the ‘parachute’ plane”, is coming soon.
Why it matters: the hinged rotor blades Cierva developed for his autogiro were the key to making a spinning wing fly, and they became a key idea for the helicopter, according to the Museo del Aire of Spain’s Air and Space Force and the Daniel Guggenheim Medal he received in 1932.
A crash that started it all
In 1919 a large bomber Cierva had designed for an army competition crashed on a test flight and was destroyed. An ordinary plane needs speed to stay in the air: if it flies too slowly, the wings stop lifting and it falls, a stall. Cierva set out to build a machine that would not fall when it lost speed and could land slowly, as the Royal Academy of History and the Guggenheim Medal citation both tell.
His answer was a rotor the engine does not drive: the air itself keeps it turning, which engineers call autorotation. His first three attempts tipped over sideways, because the blade moving into the wind lifts more than the one moving away. The fix was a hinge at the root of each blade, so it could flap up and down on every turn and even out the forces.
January 1923: the machine that came down slowly
The C.4, his first autogiro with hinged blades, flew in January 1923 at Getafe, near Madrid, piloted by Lieutenant Alejandro Gómez Spencer. Cierva was 27. Witnesses described descents that were remarkably slow and almost vertical, as Flight magazine reported in May 1923, and a Spanish account translated that year by NACA, NASA’s predecessor, said it could settle vertically without forward speed.
There is a link with our previous episode. The autogiro was tested in the wind tunnel of the Cuatro Vientos aerodynamic laboratory in Madrid, run by Emilio Herrera, the engineer of the stratospheric suit in Chapter 2. According to the certificate published in 1923, Herrera himself signed the record of the autogiro’s 4 km closed-circuit flight on 31 January 1923.
How to watch the series
Chapter 3 arrives soon on our YouTube channel and on the series page, told with real archive photographs and every fact checked against reliable sources. Until then you can watch Chapter 1, Leonardo Torres Quevedo and Chapter 2, Emilio Herrera, or see every episode on the SPANISH GENIUSES page. Subscribe to TechNews on YouTube and turn on notifications so you don’t miss it.
Read next
- New series Spanish Geniuses: Emilio Herrera, pioneer of the astronaut’s suit
- New series Spanish Geniuses: Torres Quevedo, the forgotten genius
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Sources
- Una mirada a Juan de la Cierva, inventor del autogiro – Museo de Aeronáutica y Astronáutica, Ejército del Aire y del Espacio, 2021
- Juan de la Cierva y Codorniu – Adolfo Roldán Villén, Diccionario Biográfico Español, Real Academia de la Historia
- Medalist for 1932: Juan de la Cierva – Daniel Guggenheim Board of Award / AIAA
- The “Autogiro” – M. Moreno-Caracciolo, NACA Technical Memorandum 218, July 1923
- The Cierva “Autogiro” – Flight, 24 May 1923 (reproduction)
- Pitcairn-Cierva Autogiro Company of America PCA-1A – Smithsonian National Air and Space Museum
- Emilio Herrera Linares, artífice de la ingeniería aeronáutica española – Enrique Gudín de la Lama, Llull 46 (92), 2023
