Macchi M.9
The Macchi M.9 was a flying boat bomber designed by Alessandro Tonini and produced by Macchi in Italy close to the end of World War I and shortly afterwards. Design and development. The M.9 was a conventional design for its day, with unstaggered biplane wings of unequal span and a single engine mounted pusher-fashion on struts in the interplane gap, close to the underside of the top wing. The pilot and observer sat side by side in an open cockpit. While earlier Macchi flying boats had conventional interplane struts, the M.9 introduced the Warren truss-style struts  that would become characteristic of this manufacturer's designs. Around 16 examples were delivered to the Italian Navy prior to the Armistice, and around another 14 were assembled after the end of hostilities. A small number of postwar aircraft were built with four seats under the designation M.9"bis" and were used in Switzerland for carrying passengers and mail.