Dunsfold declared inactive in 1946 but was used again in 1948 and 1949 as part of the Berlin Airlift. In 1950 The Hawker Aircraft Company acquired the lease of the site. In October 1960 the then Hawker Siddeley flight tested its Hawker P.1127 prototype, the development aircraft that led to the Hawker Siddeley Harrier, the first VTOL jet fighter bomber. Final assembly of the Harrier and the Hawk trainer aircraft was at Dunsfold. Hawker Siddeley became part of British Aerospace in 1977. On 2 July 1986 British Aerospace's deputy chief test pilot Jim Hawkins was killed at Dunsfold when his developmental
Hawker Siddeley Harrier testing. The two remaining British-based Kestrels were assigned to further trials and experimentation at RAE Bedford with one being modified to use the uprated Pegasus 6 engine. At the time of the development of the P.1127 Hawker and Bristol had also undertaken considerable development work on a supersonic version, the Hawker Siddeley P.1154, to meet a North Atlantic Treaty Organisation (NATO) requirement issued for such an aircraft. The design used a single Bristol Siddeley BS100 engine with four swivelling nozzles, in a fashion similar to the P.1127, and required the use of plenum chamber burning (PCB) to achieve supersonic speeds.