Savoia-Marchetti S.57
The Savoia-Marchetti S.57 was an Italian single-engine biplane flying boat intended for aerial reconnaissance, built by Savoia-Marchetti for "Regia Aeronautica" after World War I. Of wooden construction with a single-step hull, with pilot and observer/gunner in tandem open cockpits in the bow, the S.57 was powered by a single Isotta-Fraschini V.6. The observer had a single ring-mounted machine gun. Eighteen S.57s were accepted by "Regia Aeronautica" in 1925 and used as trainers. A sole S.57bis (improved) was built, with a Hispano-Suiza Type 42 engine.