The first British jet aircraft and the third one in the world that succesfully took to the air was the Gloster E.28/39, called the Pioneer or Squirt. Its development was no doubt the result of the work on the first British jet engine by the designer Frank Whittle and his company Power Jets Ltd. Development of the Power Jets W.1 engine began already in the pre-war years. The first experimental engine was running in 1937. In the spring of 1939, Frank Whittle visited the Gloster company and established cooperation with the chief designer of Gloster, George Carter. The Ministry of Aviation also supported this by issuing the E.28/39 specification. It required Gloster to build two experimental aircraft that would verify that the jet engine could work in an airframe. George Carter designed a small, all-metal aircraft with a nose landing gear. Only the control surfaces were covered with fabric. The landing gear could be very short, due to the absence of a propeller. In the nose of the aircraft was the intake duct of the jet engine, which forked in front of the cockpit and joined behind it. The aircraft did not carry any armament, although the specification originally called for two to four 7.7 mm machine guns. Both aircraft built, W4041 and W4046, did not have cockpit pressurization or even heating, and also lacked a wireless equipment. The flight tests of the W4041 were started with F/Lt. P. E. G. Sayer at the controls on 7 April 1941 and the aircraft reportedly took off several times during these. The official first take-off took place on 15 May 1941 at Cranwell base. The tests of the first prototype were carried out with several breaks until 1944, as the Power Jets W.1 and W.1A engines were constantly under development and changed often. In 1944, W4041 received a more powerful W.2B engine and modified tail surfaces with added stabilizers. The machine kept flying until the spring of 1945 when it was handed over to the Science Museum in South Kensington, where it is still on display. The kit consits of two grey styrene sprues, a clear plastic sprue with the canopy, fret of etches and a sheet of decals with markings for the prototype in two respective forms.