Supermarine S.4

The Supermarine S.4 was a British single-engined racing monoplane seaplane of 1925, designed by a team led by R. J. Mitchell to compete in the 1925 Schneider Trophy contest. Aviation historians regard its design as revolutionary: it was built of wood with an unbraced cantilever wing and a semi-monocoque fuselage, and it was powered by a Napier Lion engine tuned to produce 700 horsepower for a short period. The letter S stood for Schneider, and Mitchell counted the three earlier Sea Lion racers as the S.1, S.2 and S.3. Less than a month after its first flight on 24 August 1925 it raised the world seaplane speed record to 226.752 miles per hour. At the contest venue in Baltimore it went out of control during navigation trials on 23 October and dived into the sea, injuring its pilot Henry Biard. Mitchell used the experience for the S.5.