SIAI S.21

The SIAI S.21 was an Italian racing flying boat built by Societa Idrovolanti Alta Italia for the 1921 Schneider Trophy race. It was a single-seat biplane flying boat whose upper wing was shorter in span than the lower, and its 224 kW Ansaldo San Giorgio 4E-14 engine, mounted on struts above the hull and below the upper wing, drove a four-bladed pusher propeller. In test flights it proved extremely difficult to control, and the only pilot who had success with it was Guido Jannello. When Jannello fell ill at the time of the race the aircraft was withdrawn. The film Porco Rosso calls its hero plane a Savoia S.21, although the film aircraft more closely resembles the Macchi M.33.