Britain’s first jet aircraft, the experimental Gloster Aircraft Company E.28/39, was designed to provide a platform for the flight testing of the new Whittle jet engines, built at Power Jets Ltd in Rugby. In addition to being a flying test bed for this revolutionary source of power, there was a desperate need to investigate its potential for use in fighter aircraft. Sometimes referred to as the Gloster Whittle or the Gloster Pioneer, the aircraft was a low-wing monoplane design with tricycle undercarriage. It had a slightly rotund fuselage in order to accommodate the Whittle W.1 engine, with its centrifugal compressor. The engine was installed in the centre fuselage and was provided with a nose intake and a tail jet pipe. Two prototypes were built (W4041/G and W4046/G).
Designed by George Carter, the Gloster E.28/39 was completed under conditions of high secrecy at Regent Motors, Cheltenham during the Second World War – the location was chosen in order to reduce the risk of possible attack from Luftwaffe bombing raids. The E.28/39 (W4041/G) completed its taxiing trials on 7th and 8th April 1941 at Brockworth (including some initial hops) before being moved by road to RAF Cranwell for flight test. The first flight took place on 15th May 1941, lasting just 17 minutes and with Gloster chief test pilot Flt Lt Gerry Sayer at the controls.
Handling was reported as being 'light and responsive' although throttle response was said to be sluggish. The aircraft was subsequently moved to Edgehill (convenient to both Power Jets and Gloster). When Gerry Sayer suddenly disappeared whilst flight testing a Hawker Typhoon on 21st October 1942, likely killed in a mid-air collision with another Typhoon, his assistant Michael Daunt took over the development program. After further proving trials, the aircraft was subsequently transferred to Farnborough to allow service pilots to fly and assess the type. The type was flown with several early jet engines, including the Whittle W.1, W.1A, W.2/500 from Power Jets Ltd and the significantly more powerful Rover W.2B (W4046). The first flight of the second aircraft (W4046) took place on 1st March 1943 although this aircraft was later lost due to 'aileron failure' during flight testing from RAE Farnborough on 30th July 1943.
In modern procurement parlance, the Gloster E.28/39 really proved to be a perfect Technology Demonstration Programme and provided a flight envelope that extended to a maximum speed of 466 mph and a maximum altitude of 42,170 ft. It also directly led to the development of the Gloster Meteor, the first jet fighter to enter service with the RAF.
The first prototype (W4041) now resides at The Science Museum in London, whilst there are three full-size replicas, one mounted on a plinth alongside the main entrance to what is now Farnborough Airport on the site of the former Royal Aircraft Establishment, a second on a roundabout at Lutterworth, close to the former home of Power Jets Ltd, and a third at the Jet Age Museum in Gloucester.