| S.4 | |
|---|---|
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| |
| Official photograph of the S.4, from the magazine Flight in October 1925 | |
| Role | Racing floatplane |
| National origin | United Kingdom |
| Manufacturer | Supermarine |
| Designer | R. J. Mitchell |
| First flight | 24 August 1925 |
| Status | Destroyed 23 October 1925 |
| Number built | 1 |
The Supermarine S.4 was a 1920s British single-engined monoplane built by the company Supermarine. Designed by a team led by the company's chief designer, R. J. Mitchell, it was designed to compete in the 1925 Schneider Trophy contest.
Mitchell's design is considered by historians as revolutionary. Built of wood with an unbraced cantilever wing, the S.4 was powered by a Napier Lion engine developed to produce 700 horsepower (520 kW) over a short period. Less than a month after its maiden flight on 24 August 1925, it raised the world's seaplane speed record to 226.752 miles per hour (364.922 km/h).
At Bay Shore Park in Baltimore in the US, the venue of the 1925 contest, the S.4's rear end was damaged by a falling pole during a gale before the event. During navigation trials on 23 October the repaired aircraft was observed to be performing well, but then, for reasons that have not been fully explained, it went out of control, and was destroyed when it dived into the sea from 100 feet (30 m), injuring the pilot, Henry Biard. Mitchell then used his experience gained working on the S.4 to design its successor, the Supermarine S.5.