1933年底,意大利萨伏亚-马切蒂飞机公司开始设计一种三发8卧铺的客机。飞机为混和结构,机翼为全木结构,机身为钢管焊接构架,前部机身为铝蒙皮,中部机身上部分为铝蒙皮或胶合板,侧面和腹部为布蒙皮,机身后部为布蒙皮。和许多30年代初期设计的飞机一样,为了加强垂直尾翼和水平尾翼的强度,垂直尾翼用左右两条拉线加强,水平尾翼下每侧有两根平行的支撑竿 At the end of 1933, the Italian Savoia-Marchetti Aircraft Company started to design a three-engine, 8-berth passenger plane. Aircraft for the hybrid structure, the wing is all-wood structure, body welded steel pipe structure, the front fuselage is aluminum skin, the central part of the fuselage is aluminum skin or plywood, the side and the abdomen for the cloth skin, the fuselage The back is a cloth skin. Like many aircraft designed in the early 1930s, in order to enhance the strength of the vertical tail and horizontal tail, the vertical tail is reinforced with two left and right cords with two parallel support rods on each side below the horizontal tail