The SIAI S.21 was an Italian racing

flying boat A flying boat is a type of fixed-winged seaplane with a hull, allowing it to land on water. It differs from a floatplane in that a flying boat's fuselage is purpose-designed for floatation and contains a hull, while floatplanes rely on fusela ...

built by SIAI for the 1921 Schneider Trophy race.

Design and development

The S.21 was a single-seat

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...

with its upper wing being of shorter span that its lower wing. Its

Ansaldo San Giorgio 4E-14 Ansaldo Energia S.p.A. is an Italian power engineering company. It is based in Genoa, Italy. The absorbed parent company, Gio. Ansaldo & C., started in 1853. It was taken over by Leonardo S.p.A. In 2011, Leonardo S.p.A. sold 45% stake in ...

engine was mounted on struts above its

hull Hull may refer to: Structures * Chassis, of an armored fighting vehicle * Fuselage, of an aircraft * Hull (botany), the outer covering of seeds * Hull (watercraft), the body or frame of a ship * Submarine hull Mathematics * Affine hull, in affi ...

and below its upper wing and drove a four-bladed pusher

propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...

. Small stabilizer floats were mounted beneath the lower wing on each side.

Operational history

During test flights, the S.21 proved extremely difficult to control, and the only pilot who had success with it was Guido Jannello, who had already made an impression at the 1918 Schneider Trophy, in a

Savoia S.13 The SIAI S.13 was an Italian biplane reconnaissance flying-boat from 1919. Design and development Designed by the SIAI-Marchetti, Società Idrovolanti Alta Italia (SIAI) as a smaller version of the earlier SIAI S.12, S.12, the S.13 was a single- ...

. When Jannello fell ill at the time of the 1921 Schneider Trophy race and was unable to pilot it, the S.21 was withdrawn from the race.

Popular culture

* In the Japanese animated film '' Porco Rosso'', the main protagonist's plane is referred to as a Savoia S.21. However, it is patterned after this plane and does not closely resemble the real S.21, and more closely resembles the

Macchi M.33 The Macchi M.33 was an Italian racing flying boat which competed in the 1925 Schneider Trophy race. Design and development The Macchi M.33 was a single-seat, wooden, shoulder-wing monoplane flying boat of very clean aerodynamic design for its t ...

Operators

;

Specifications

Notes

References

Aviation: SIAI racing seaplanes
{{DEFAULTSORT:Siai S.21 1920s Italian sport aircraft S.21 Flying boats Schneider Trophy Biplanes Single-engined pusher aircraft Aircraft first flown in 1921