Supermarine Type 553

The Supermarine Type 553 was a British experimental jet fighter developed by Supermarine in the late 1940s as a response to the Royal Air Force’s need for a high‑speed, swept‑wing interceptor. Drawing on lessons learned from the propeller‑driven Spitfire and the early jet‑powered Supermarine Attacker, the Type 553 featured a thin, 45‑degree swept wing, a single Rolls‑Royce Derwent V turbo‑jet and a conventional tailplane with all‑moving elevator. Its fuselage employed a semi‑monocoque aluminium structure and incorporated a pressurised cockpit with a bubble canopy that gave the pilot excellent forward visibility. Flight trials began in 1949 at RAF Boscombe Down, where the aircraft demonstrated a maximum speed of roughly 620 mph at altitude and a service ceiling above 45 000 feet, considerably surpassing contemporary piston‑engine fighters. Although the Type 553 never entered production, its aerodynamic data and handling characteristics directly influenced the design of the successful Supermarine Swift and later the Hawker Hunter. The programme highlighted Supermarine’s transition from propeller‑driven designs to modern jet technology and cemented its reputation as a pioneer in swept‑wing research during the early jet age. The aircraft also tested early radar and four 20 mm cannon armament.