Hawker Siddeley P.1127 Hawker Siddeley P.1127 The Hawker P.1127 and the Hawker Siddeley Kestrel FGA.1 are the experimental and development aircraft that led to the Hawker Siddeley Harrier, the first "vertical and/or short take-off and landing" (V/STOL) jet fighter-bomber. P.1127 development began in 1957, taking advantage of the Bristol Engine Company's choice to invest in the creation of the Pegasus vectored-thrust engine. Testing began in July 1960 and by the end of the year the aircraft had achieved both vertical take-off and horizontal flight. The test program also explored the possibility of use upon aircraft carriers, landing on in 1963. The first three
Jet Age Military aviation had entered the jet age somewhat earlier, during the closing stages of World War II. In the early postwar years, the increasing use of jet aircraft had little significant impact, serving mainly to continue the slow but steady improvements in performance seen in the past. Supersonic flight brought about a step change in aircraft performance. The Bell X-1, first to break the sound barrier in level flight, was an experimental rocket-powered type, and production jets which followed it into service could fly little faster. The first jet aircraft designed from the outset for supersonic flight was the British