An idea at the opera

Juan de la Cierva, born in 1895 into a political Spanish family, was building gliders at eight and an aeroplane with a propeller cut from a bar counter as a teenager. His first autogiros, the C.1 to C.3, rolled over on take-off because the advancing blade lifted more than the retreating one. Watching an opera, he realised that his flexible bamboo model rotors had flexed to cure the problem. His answer was the flapping hinge, and in January 1923 his C.4 flew at Getafe, the first successful flight of a stable rotary-wing aircraft.

Weir’s money, Avro’s airframes

A demonstration at Farnborough in 1925 drew an invitation to Britain, and on 24 March 1926 the Cierva Autogiro Company was formed with the backing of the Scottish industrialist James George Weir. Cierva concentrated on rotors and licensed the rest: Avro built most of the airframes, starting with the C.8. In 1928 a C.8L4 toured 4,800 km round the British Isles and then flew from London to Paris, the first rotating-wing aircraft to cross the English Channel. Licensees followed in Germany, France and America, where Pitcairn and Kellett built autogiros.

The C.30 and direct control

The breakthrough of the 1930s was direct control. Instead of ailerons and elevators that went limp at low speed, the pilot tilted the whole rotor hub with a hanging stick. The C.30, first flown in April 1933, was the first production autogiro with it. Built by Avro as the Model 671, by Lioré et Olivier as the C.301 and by Focke-Wulf, it ran to 148 aircraft and made the autogiro a practical, if niche, flying machine. Cierva won the Guggenheim Medal in 1932.

Croydon, 1936

On 9 December 1936 Juan de la Cierva was a passenger aboard a KLM DC-2 that crashed taking off from Croydon in fog; he was 41. He had sided with Franco in the Spanish Civil War and helped arrange the Dragon Rapide that carried the general from the Canaries to Morocco. His chief technical officer, James Bennett, took the gyrodyne idea forward as the C.41 before the war intervened; it later flew as the Fairey FB-1.

The Air Horse and the end

Weir had meanwhile built small helicopters of his own, the W.5 of 1938 and the W.6 of 1939. In 1943 Weir’s aircraft department was reconstituted as the Cierva Autogiro Company to design helicopters, producing the W.14 Skeeter and the W.11 Air Horse, a three-rotor giant that was the world’s largest helicopter when it flew in December 1948. On 13 June 1950 the first Air Horse crashed, killing the company’s chief test pilot Alan Marsh and two others. Weir withdrew, and in January 1951 Saunders-Roe took over the contracts.

מפעלים

• Hamble · Hamble, Southampton — Company base from 1946
• Cunliffe-Owen, Eastleigh · Eastleigh, Southampton — Contracted to build the two Air Horses

אֲנָשִׁים

• Juan de la Cierva · inventor and chief designer — 1895–1936; inventor of the autogiro and the flapping hinge
• James George Weir · financial backer — Scottish industrialist and aviator
• James Allan Jamieson Bennett · chief technical officer 1936–1939 — Developed the gyrodyne concept
• Alan Marsh · manager and chief test pilot — Killed in the Air Horse crash, 1950

שיאים וראשונות

• First successful rotary-wing flight, C.4, January 1923
• First rotating-wing aircraft to cross the English Channel, C.8L4, 1928
• W.11 Air Horse, world’s largest helicopter at its 1948 debut