Saunders-Roe SR.53

Developed in the early 1950s by the British firm Saunders‑Roe, the SR.53 was an experimental interceptor that combined a conventional jet engine with a powerful rocket motor to achieve rapid climb and high‑altitude performance. The concept originated from the Air Ministry’s Specification ER.103, which called for a point‑defence fighter capable of reaching 60,000 ft in minutes to counter the emerging threat of high‑speed Soviet bombers. The aircraft featured a sleek, low‑drag fuselage, a mid‑wing layout and a Rolls‑Royce Avon turbofan feeding the jet propulsion system, while a detachable rocket motor, supplied by the Rocket Propulsion Establishment, used hydrogen peroxide and kerosene as propellants. First flown on 16 March 1954, the SR.53 completed a successful test programme that demonstrated climb rates of over 30,000 ft /min and a top speed exceeding Mach 1.2 in rocket‑boosted mode. Although the program was cancelled in 1957 due to changing defence priorities and the development of guided missiles, the SR.53 provided valuable data on mixed‑propulsion control, high‑altitude aerodynamics and the integration of rocket thrust in aircraft, influencing later designs such as the SR.177 and contributing to the United Kingdom’s early exploration of rapid‑response interceptor concepts.

Saunders-Roe

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