Italian armistice of 1943, though some remained in service with both the Italian Social Republic and the Italian Co-Belligerent Air Force. Several examples survived the war and went on to serve with the Aeronautica Militare Italiana, but by 1950 these had all been retired. SM.81s serving in Ethiopia had markings applied to distinguish them in SAR missions. The normal camouflage pattern was yellow, green and brown. The all-over dark olive green scheme was introduced later, when the aircraft were used only in transport missions. Variants SM.81 Three-engine bomber, transport aircraft, 535 built. SM.81B Experimental twin-engine prototype, one built. Operators Chinese Nationalist Air Force received three aircraft, all were lost in training accidents in February 1938 at Yichang. Regia Aeronautica Aviazione Legionaria 64 aircraft Italian Co-Belligerent Air Force Aeronautica Nazionale Repubblicana Aeronautica Militare Italiana operated this type postwar. Spanish Air Force Specifications (Savoia-Marchetti SM.81b with Alfa Romeo 125 R.C.35 engines) See also References Citations Bibliography Angelucci, Enzo and Paolo Matricardi. World Aircraft: World War II, Volume I (Sampson Low Guides). Maidenhead, UK: Sampson Low, 1978. . Apostolo, Giorgio. The Savoia Marchetti S.M.81 (Aircraft in Profile number 146). Leatherhead, Surrey, UK: Profile Publications Ltd.,1967. Lembo, Daniele, SIAI 81 Pipistrello, Aerei nella Storia, n.33. Passingham, Malcolm. "Savoia-Marchetti SM81". Aircraft Illustrated, May 1977, Vol 10 No 5. pp. 182–187. Mondey, David. The Hamlyn Concise Guide to Axis Aircraft of World War II. Chancellor Press, 2002. Sutherland, Jon & Diane Canwell: Air War East Africa 1940–41 The RAF versus the Italian Air Force. Barnsley (South Yorkshire) Pen and Sword Aviation, 2009. . SM.081 1930s Italian bomber aircraft World War II Italian bombers Trimotors Low-wing aircraft Aircraft first flown in 1934