Saunders-Roe SR.53

The Saunders-Roe SR.53 was a British prototype interceptor aircraft of mixed jet and rocket propulsion, developed for the Royal Air Force by Saunders-Roe in the early 1950s. It was powered by a single Armstrong Siddeley Viper turbojet and a de Havilland Spectre rocket engine, with the two exhausts mounted one above the other beneath the tail. The company received an Instruction to Proceed for three prototypes on 30 October 1952, and in January 1954 the Ministry reduced the order to two, which were built side by side at Cowes. Delays in the Spectre engine pushed the first flight back to 1957, when Squadron Leader John Booth flew XD145 on 16 May. The second prototype, XD151, first flew on 6 December 1957 and was destroyed in a test flight in June 1958. The programme was formally cancelled in July 1960 after 56 test flights, and the first prototype has been preserved.