pilots in April 1939 and an official approach from the Air Ministry followed. As no existing aircraft was suitable for adaptation to take the new jet engine, and Gloster did not have much workload in its design department, Gloster received a contract in early 1940 – to design and build Britain's first jet aircraft. Two airframes were built in secrecy. Due to the risk of bombing, one of the aircraft was built offsite from Brockworth at Regent Motors Cheltenham. On 15 May 1941, the first official test flight of the Gloster E.28/39 W 4041/G with a turbo-jet engine, invented by Sir Frank Whittle took off from RAF Cranwell (earlier taxying trials, in which the E.28/39 briefly became airborne, and therefore "flew", were carried out at the company's airfield at Brockworth). Although the E.28.39 could in theory be used as a fighter, a specific fighter design was required and Gloster began work on a twin engine jet design. Once the E.28/39 had flown, the Air Staff told Gloster to stop work on their F.18/40 nightfighter (other aircraft could be adapted to replace it) to concentrate on the jet fighter. The jet design became the Gloster Meteor, the only jet to be used in combat by the Allied Forces during the Second World War. First flying with the RAF in 1943, the Meteor commenced operations in mid-1944, only some weeks later than the world's first operational jet, the German Messerschmitt Me 262. Crucially, it became the first RAF aircraft with a high enough top speed to enable it to fly alongside V1 flying bombs, tip them under the wing so as to render the V1's gyro incapable of recovery and the V1s crashed prematurely to earth in open countryside before they could reach London. 1945 – Setting world airspeed records In 1945, a Meteor F Mk.4 prototype, stripped of armament, achieved a World Airspeed Record of with Group Captain H. Wilson at the controls. During early 1946, another F Mk.4 prototype was used to set a world air speed record of 616 mph (991 km/h) true airspeed with Group Captain "Teddy" Donaldson flying the highly modified Meteor, nicknamed "Yellow Peril." The second pilot in the High Speed Flight, Bill Waterton achieved 614 mph. During the record attempt Donaldson became the first man to break the 1,000 km/h barrier, winning the Britannia Trophy and a Bar to his AFC. Meteors remained in service