Ambrosini S.A.I. 107

Despite highly enthusiastic flight test reports, the need for increased production of combat aircraft necessitated the shelving of the S.A.I.7 trainer, but the aerodynamic qualities of the 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 and, powered by a 540-h.p. Isotta-Fraschini Gamma, was flown early in 1942.

Working at the Societa Aeronautica Italiana of Ing Angelo Ambrosini, Sergio Stefanutti developed the S.107 lightweight fighter from the S.7 tandem two-seat aerobatic trainer and competition aircraft. Flown for the first time early in 1940, the S.107 was powered by a 515hp Isotta-Fraschini Gamma R.C.35-I 12-cylinder inverted-Vee air-cooled engine and armament was one 7.7mm machine gun. As initially flown, the S.107 was fitted with a long, faired windscreen extending over the engine in an attempt to reduce aerodynamic drag. This was found to impair vision from the cockpit, and it was replaced by a stepped windscreen. Performance was demonstrated at Guidonia, and progressive development of the basic design led to the S.207, the sole example of the S.107 being lost in an accident on 18 July 1941.

Engine: Isotta-Fraschini Gamma RC.35-I, 515 hp
Take-off weight: 1600 kg / 3527 lb
Empty weight: 1280 kg / 2822 lb
Wingspan: 9.00 m / 29 ft 6 in
Length: 8.00 m / 26 ft 3 in
Height: 2.40 m / 7 ft 10 in
Wing area: 13.10 sq.m / 141.01 sq ft
Max. speed: 500 km/h / 311 mph
Range: 800 km / 497 miles