The SIAI S.51, Savoia Marchetti S.51 or Savoia S.51 was an Italian racing flying boat built by SIAI for the 1922 Schneider Trophy race.
Design and development
The S.51 was a single-seat sesquiplane flying boat. It was powered by a single 300 horsepower (220 kW) Hispano-Suiza 8FV8 engine, mounted on two N struts above the hull and below the upper wing, which drove a two-bladed propeller in a pusher configuration. The inclined interplane struts were mounted in a V configuration. The lower wings had small stabilizing floats mounted on inclined struts so that they hung below and outboard of the outer tips of the lower wing.[1]
SIAI later based the design of the hull of its S.58 flying boat fighter of 1924 on that of the S.51's hull.[2]
Operational history
Italy entered the S.51 in the 1922 Schneider Trophy race along with two Macchi M.17 flying boats in competition with a British Supermarine Sea Lion II flying boat. The race was held at Naples on 12 August.[3][4]
The S.51 capsized in an accident during the seaworthiness trials before the race.[5] Righted by its crew, it completed the race, piloted by Alessandro Passaleva but could only take second place, with the Sea Lion a comfortable 2 min 22 s ahead. The course required 13 laps, a total distance of 370 km (230 mi), over which the S.51 averaged 229.57 km/h (142.65 mph).[3][4]
On 28 December 1922 the S.51, flown again by Passaleva, set a world speed record for seaplanes of 280.155 km/h (174.080 mph).[6][7]
Green, William, and Gordon Swanborough. The Complete Book of Fighters: An Illustrated Encyclopedia of Every Fighter Aircraft Built and Flown. New York: SMITHMARK Publishers, 1994. ISBN0-8317-3939-8.
Vašiček, Radko. "When Seaplanes Ruled the Sky." Aviation History, September 2002