After incorporation of Societa Aeronautica Italians with Ing A. Ambrosini & Cie, they specialised in fast tourers and sporting monoplanes, though SA11 was biplane. In the immediate pre-war years its Passignano plant was responsible for a successful series of light cabin monoplanes.
The series of light monoplanes had culminated in the S.A.I.7, The series of light monoplanes had culminated in the S.A.I.7 which, of exceptionally clean design and powered by a 280-h.p. Hirsh H.M.508D air-cooled engine, gained the 100-km. closed circuit record for F.A.I. Category I aircraft with a speed of 244 m.p.h. in 1939. The S.A.I.7 possessed excellent flight characteristics. Stefanutti had designed the aircraft with the alternative role of fighter trainer in mind, and a fully militarized trainer prototype flew in 1941. The original prototype featured a long, faired windscreen which extended to the front of the engine cowling to reduce drag, but the military trainer had an orthodox cockpit canopy for the tandem-seated pupil and instructor, and the German Hirsh was replaced by a 280-h.p. Isotta-Fraschini Beta R.C.I0.
The S.A.I.7 trainer basic design were such that Stefanutti contemplated its adaptation as a lightweight interceptor fighter. The initial single-seat model, the S.A.I.I07, was built for research purposes.
The S.A.I.I07 was externally similar to the S.A.I.207, which was built to full fighter requirements and carried an armament of two 20-mm. cannon and two 12.7-mm. machine guns. In dives the S.A.I.207 fighter attained an indicated air speed of 466 m.p.h. at 10,000 ft. (representing a true air speed of 596 m.p.h., or Mach 0.86), and maximum level speed was 357 m.p.h., which was attained on the 750 h.p. provided by an Isotta-Fraschini Delta R.C.40 engine. 2,000 were ordered, though only 13 completed. The type being replaced by proposed production of the SAI 403, work on which finished at war's end.
Encouraged by the performance of the S.A.I.207, Sergio Stefanutti developed the more ambitious S.A.I.403 Dardo, which featured increased wing area and redesigned tail surfaces. Carrying a similar armament to that of its predecessor, the Dardo was powered by a 750-h.p. Delta R.C.21/60 engine which provided a maximum speed of 403 m.p.h. Large-scale production of the Dardo was planned, but the armistice precluded further development.
Other wartime activities of the S.A.I.-Ambrosini concern were the construction of the AL-12P troop- and cargo-carrying glider designed by Aeronautica Lombarda S.A., and the development of the Ambrosini AR "flying bomb". Conceived by General Ferdinando Raffaelli as an anti-shipping weapon, the flying bomb was powered by a 1,000-h.p. Fiat A.80 radial engine and was to have been flown off the ground by a pilot who would then bail out, the bomb being directed to its destination by remote radio-control. Flight tests began on 13th June 1943, and four further examples were built at the Venegono plant. Flight trials were successful and a speed of 225-230 m.p.h. was expected, but the bomb was too late to see operational service.
In 1948 the S1001 Grifo broke more records. The S 7 was delivered in small numbers and developed into the Super S 7 (1950s). The F 7 Rondone was 3/4-seat cabin tourer.