Supermarine S.4, S.5, S.6 and S.6B

The Supermarine S.4, S.5, S.6 and S.6B were a series of Schneider Trophy winning floatplanes that were designed by R.J. Mitchell, and that played a part in the design of the Supermarine Spitfire by giving him experience of designing high speed stressed skin monoplanes.