Supermarine Swan  The Supermarine Swan was a 1920s British experimental amphibian aircraft built by Supermarine at Woolston. Only one was built and it was used for a passenger service between England and France. The Swan was designed by R. J. Mitchell, chief designer at Supermarine as an experimental wooden twin-engined biplane amphibian aircraft, in parallel with the Supermarine Scylla design for a replacement for the Royal Air Force's Felixstowe F5s. First flown on 25 March 1924 (as serial "N175"), the Swan was powered by two 350 hp (261 kW) Rolls-Royce Eagle IX engines. It was re-engined with two 450 hp (336 kW) Napier Lion engines and had the landing gear removed for evaluation at the Marine Aircraft Experimental Establishment in August 1924. In 1926, it was registered "G-EBJY" and loaned to Imperial Airways as a flying boat with accommodation for 10 passengers until it was scrapped in 1927.