Sir Frank Whittle's jet aircraft engine was patented in 1932, and Power Jets, Ltd. formed in 1936. The Whittle Unit bench test engine first ran on April 12, 1937. In 1939, the British Air Ministry placed a contract for the W.1 engine to be flight tested on the new Gloster E.28/39 aircraft. During taxiing tests, the W.1X non-airworthy engine unofficially became the first British turbojet to be airborne when the E.28/39 made short, straight hops. The W.1 flew officially in the E.28/39 on May 15, 1941.
The W.1X and drawings of the W.2B production engine were delivered to the General Electric Company on October 1, 1941. GE's improved and uprated version, the IA, powered the first U.S. jet aircraft, the Bell XP-59A Airacomet on October 2, 1942. At the end of its useful life, the W.1X was returned to England. On November 8, 1949, the W.1X was presented to the Smithsonian by Power Jets, Ltd.