for organizing a squadron of S.55s for Atlantic crossings, culminating in his 1933 flight with 24 aircraft to Chicago's Century of Progress International Exposition. On 1 July 1933, General Balbo commanded a flight of S-55s from Orbetello, Italy, completing the flight in just over 48 hours, maintaining a tight "V" formation. These large fleets of aircraft were sometimes called a "Balbo". The aircraft went on to serve in the Regia Aeronautica as a long-range bomber and patrol aircraft, but by World War II, the last S.55s were no longer serviceable and were in reserve. Variants S.55 Prototypes and original production model delivered from 1927 to 1930, 90 built, including two prototypes. S.55C Civil variant delivered from 1925 to 1926, eight built. S.55P Improved civil variant with enlarged hull for ten passengers and enclosed cockpits delivered from 1928 to 1932, 23 built. S.55A Military variant delivered with 418 kW (560 hp) Fiat A.22R engines, 16 built. S.55M Variant with some wood structures replaced by metal, seven built by Piaggio in 1930. S.55 Scafo Allargato Widened and deepened hull and enclosed cockpits, 16 built by Savoia-Marchetti and 16 built by CANT. S.55 Scafo Allargatissimo Variant with greatly enlarged hull, 20 built by Savoia-Marchetti, 16 built by Macchi and six built by CANT. S.55X Variant fitted with Isotta Fraschini Asso 750 engines for North Atlantic formation flights, later armed and used as a reconnaissance-bomber. 25 built. Operators Civil operators Aero Espresso Italiana Società Aerea Mediterranea Aeroflot Aero Transport Company d.b.a. AirVia. Marine Air Transport Co. Alaska Airways Military operators Regia Aeronautica Brazilian Navy (8 airplanes) Spain (1937) Spanish Air Force Royal Romanian Naval Aviation (7 units) Surviving aircraft The last remaining example is preserved in Brazil, at the TAM "Asas de um sonho" museum, at São Carlos, São Paulo. The aircraft, registered I-BAUQ and named "Jahú", was the S.55 used by Commander João Ribeiro de Barros in his crossing of the South Atlantic in 1927. Specifications (S.55) See also References Bibliography External links Savoia-Marchetti S-55 S.55 1920s Italian airliners 1920s Italian patrol aircraft Flying boats Twin-fuselage aircraft Twin-engined push-pull aircraft High-wing aircraft Transatlantic flight Aircraft first flown in 1924