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
Assisted take-off more miles of runway to take off fully laden. This was exacerbated by the relatively low power available from jet engines at the time—for example the Boeing B-52 Stratofortress required eight turbojet engines to yield the required performance, and still needed RATO for very heavy payloads (a proposed update of the B-52 replaces these with half the number of much more powerful engines). In a Cold War context, RATO and JATO bottles were seen as a way for fighter aircraft to use the undamaged sections of runways of airfields which had been attacked. Glider aircraft which do not have an