Hawker Siddeley Harrier cancelled after the release of the British Government's 1957 Defence White Paper, which advocated a policy shift away from manned aircraft and towards missiles. This policy resulted in the termination of the majority of aircraft development projects then underway for the British military. Hawker sought to quickly move on to a new project and became interested in Vertical Take Off/Landing (VTOL) aircraft, which did not need runways. According to Air Chief Marshal Sir Patrick Hine this interest may have been stimulated by the presence of Air Staff Requirement 345, which sought a V/STOL ground attack fighter for the Royal Air
Hawker Harrier it was underpowered, and it had an inferior bombload to the Hawker Horsley, the aircraft it was meant to replace. It was therefore modified to carry a torpedo. On testing the modified aircraft, however, it was found to still be underpowered, being incapable of taking off with a torpedo, gunner and full fuel load. It was therefore not considered further, the competition ultimately being won by the Vickers Vildebeest. The prototype was used by Bristol as an engine testbed, flying with the 870 hp (649 kW) Bristol Hydra and the Bristol Orion engines. Hawker Harrier The Hawker Harrier was an