A Swiss wing in Croydon

General Aircraft began as a vehicle for one idea. On 27 February 1931 GAL was formed to build aircraft using the monospar wing of the Swiss engineer Helmut J. Stieger, a structure built around a single main spar. At Croydon Aerodrome between 1932 and 1934 it produced about 28 examples of the twin-engined Monospar light transports. In October 1934 the investment group British Pacific Trust recapitalised the business as a new General Aircraft Limited, adding the London Air Park at Hanworth near Feltham, and production moved there in early 1935. The ST-25 Jubilee, 59 built, became the best seller.

Gliders for Churchill’s airborne army

Subcontracting kept the factory busy. In 1936 GAL won an order for 89 Hawker Fury II fighters and later converted 125 Hawker Hinds into trainers; in 1938 it bought the Cygnet light aircraft design from C.W. Aircraft. Then the war gave it a speciality. In June 1940 Winston Churchill ordered the creation of a British airborne force, and that month the Ministry of Aircraft Production asked General Aircraft for an eight-seat glider. The result, the Hotspur, flew on 5 November 1940; 1,015 were built and it became the basic trainer of the glider schools.

Flying a tank into battle

The company’s greatest feat was the Hamilcar, a glider so big that no British glider of its size had been built before and only four-engined bombers could tow it, designed to carry a Tetrarch light tank whose crew sat inside it in flight, starting the engine just before the glider cast off. A half-scale prototype crashed on its only flight in 1941; the full-size Hamilcar flew on 27 March 1942. Some thirty landed tanks, 17-pounder anti-tank guns and vehicles in Normandy during Operation Tonga in June 1944, and they went again to Arnhem and across the Rhine. The Hamilcar was used only by British airborne forces, and 22 were converted into the powered Hamilcar X.

The most difficult aircraft Eric Brown ever flew

GAL also explored tailless flight with the GAL.56 gliders. Robert Kronfeld flew the first on 13 November 1944 at Farnborough. The naval test pilot Eric “Winkle” Brown later described it as the most difficult aircraft he ever flew, and on 12 February 1948 Kronfeld was killed when a stall test turned into an uncontrollable dive. Meanwhile, during the war, Hanworth repaired Spitfires, adapted Hurricanes for catapult launch from merchant ships and, from 1943, assembled Sikorsky helicopters imported from America for the RAF and Fleet Air Arm.

Houses, car bodies and a merger

After the war General Aircraft made prefabricated houses and car bodies, but its big hope was the GAL.60 Universal Freighter, a descendant of the Hamilcar. Hanworth was too small to build it, so GAL approached Blackburn, which had space at Brough. On 1 January 1949 the companies merged as Blackburn and General Aircraft. The GAL.60 prototype was taken by road to Brough and first flew there on 20 June 1950; developed into the Beverley, 49 were built for the RAF. The Hanworth factory was later closed.

Fabrieken

• Croydon · Croydon Aerodrome, Surrey — Monospar production 1932–1934
• Hanworth · London Air Park, Hanworth, Feltham — Main works from 1935; premises built in 1917 by Whitehead Aircraft; later closed
• Fairoaks · Fairoaks Aerodrome, Surrey — RAF elementary flying school and wartime Beaufighter repairs

Mensen

• Helmut J. Stieger · founder, inventor of the monospar wing
• F. F. Crocombe · chief designer — Worked on the Universal Freighter concept from 1939
• Robert Kronfeld · test pilot — Flew the first GAL.56 in 1944; killed in one in 1948
• Harold “Tim” Wood · chief test pilot — Flew the GAL.60 at Brough, 1950

Records en primeurs

• Hamilcar was the first British glider designed to carry a light tank; such a large glider had never before been built for the British military
• Hotspur became the basic trainer of the British glider schools