The SIAI S.21 was an Italian racing

flying boat A flying boat is a type of seaplane with a hull, allowing it to land on water. It differs from a floatplane in having a fuselage that is purpose-designed for flotation, while floatplanes rely on fuselage-mounted floats for buoyancy. Though ...

built by SIAI for the 1921

Schneider Trophy The Coupe d'Aviation Maritime Jacques Schneider, also known as the Schneider Trophy, Schneider Prize or (incorrectly) the Schneider Cup is a trophy that was awarded first annually, and later biennially, to the winner of a race for seaplanes and ...

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 A wing is a type of fin that produces both Lift (force), lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a planform (aeronautics), planform. Wing efficiency is expressed as lift-to-d ...

being of shorter span that its lower wing. Its Ansaldo San Giorgio 4E-14 engine was mounted on struts above its

hull Hull may refer to: Structures * The hull of an armored fighting vehicle, housing the chassis * Fuselage, of an aircraft * Hull (botany), the outer covering of seeds * Hull (watercraft), the body or frame of a sea-going craft * Submarine hull Ma ...

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

propeller A propeller (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 a working flu ...

. 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. When Jannello fell ill at the time of the 1921 Schneider Trophy race and was unable to pilot it, the S.21 was withdrawn from the race.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 is a 1992 Japanese Anime, animated Adventure film, adventure fantasy film written and directed by Hayao Miyazaki, based on his 1989 manga ''Hikōtei Jidai''. The film stars the voices of Shūichirō Moriyama, Tokiko Kato, Akemi Okamura and Akio ...

'', 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 ti ...

Operators

;

Specifications

Notes

References

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