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 Hoopoe fitted during the short trial period, two variants of the Bristol Mercury were later replaced by an Armstrong Siddeley Jaguar and Panther with an increase in performance. Trials at Felixstowe in 1929 with floats fitted showed that the aircraft was severely underpowered with the Mercury powerplant, requiring the change to the Jaguar engine. Service interest in the type had waned by autumn 1930 although the single prototype continued in development flying with Armstrong Siddeley and the Royal Aircraft Establishment until 1932 when the Hoopoe was scrapped. Hawker Hoopoe The Hawker Hoopoe was a British prototype naval fighter aircraft designed and