Hawker Siddeley much larger firms. Out of this decision, came the "order" that all future contracts being offered had to include agreements to merge companies. In 1959, Folland Aircraft was acquired, followed by de Havilland Aircraft Company and Blackburn Aircraft in 1960. In 1963, the names of the constituent companies were dropped, with products being rebranded as ""Hawker Siddeley"" or ""HS"". In this period, the company developed the first operational, and, by far, the most successful VTOL jet aircraft, the Harrier family. This aircraft remained in production into the 1990s and remains in service. In 1948, Hawker Siddeley acquired a factory in
1956 Hawker Hunter multiple aircraft accident 1956 Hawker Hunter multiple aircraft accident On 8 February 1956 the Royal Air Force lost six Hawker Hunter jet fighters in a multiple aircraft accident. Eight aircraft from RAF West Raynham had been carrying out a 4x4 dogfight exercise at . Upon completion of the exercise the eight Hunters diverted to RAF Marham but due to bad weather six of the aircraft were lost including one fatality. The eight Hunter F1s from the Day Fighter Leader Squadron of the Central Fighter Establishment departed RAF West Raynham, Norfolk, England at 10:50 to carry out the exercise at in the local area.