Gloster F.9/37
The Gloster F.9/37, also known as the Gloster G.39, was a British twin-engined design from the Gloster Aircraft Company for a cannon-armed heavy fighter to serve with the Royal Air Force, planned before the Second World War. The F.9/37 was rejected in favour of other designs.
A development of the F.9/37 as a night fighter, for a new Air Ministry Specifications F.29/40 – known unofficially as the Gloster Reaper – was dropped so that Gloster could concentrate on existing work and on the nascent British jet projects.
Design and development
Gloster had designed a twin-engined turret-fighter for specification F.34/35 but the single-engined Boulton Paul Defiant for F.9/35 was seen to cover both requirements and the F.34/35 design dropped. Less than two years later, F.9/37 for a "twin-engined single-seat fighter with fixed armament" was issued. The F.9/37 was designed under the direction of George Carter, his first for Gloster, to F.9/37 as a single-seat fighter carrying an armament of four 0.303 in (7.7 mm) Browning machine guns and two 20 mm Hispano cannon in the nose. Intended for dispersed production by semi-skilled labour, the structure broke down into sub-assemblies.A prototype with 1,060 hp Bristol Taurus T-S radial engines flew on 3 April 1939 and demonstrated excellent performance, its maximum speed of being the best recorded by a British fighter at the time. Test flights revealed that the prototype was very manoeuvrable and "a delight to fly". After being badly damaged in a landing accident in July 1939, it was re-engined with 900 hp Taurus T-S-IIIs in 1940, which reduced its performance. A second prototype with 880 hp Rolls-Royce Peregrine I liquid-cooled, inline engines flew on 22 February 1940; it proved capable of at.