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
Supermarine Type 324 Supermarine Type 324 The Supermarine Type 324 and Type 325 were British two-engined fighter designs proposed as the replacement for the Supermarine Spitfire and Hawker Hurricane. Neither of them nor a revised design - the Type 327 - to carry cannon was accepted for development and production. As an aircraft to succeed the Hurricane and Spitfire then entering service, Air Ministry specification F.18/37 required a 400+ mph (at 15,000 ft) fighter with twelve .303 inch machine gun armament. Hawker Aircraft submitted a single seat, single engine design with two possible engines, the Hawker Tornado powered by the Rolls-Royce Vulture and