Designed between October 1938 and April 1939 by Sergio Stefanutti as a two-seat high-speed tourer monoplane, the Ambrosini S.A.I.7 was a low-wing cantilever monoplane of wooden construction with fully retractable landing gear.
The first two aircraft were specifically intended to take part in the IV Avio Raduno del Littorio contest for touring aircraft, and they flew within days of each other, only shortly before the competition opened at Rimini aerodrome on 15 July 1939. Both aircraft had an additional streamlined glazed section added between the nose and the normal cabin enclosure for the contest. The S.A.I.7s did not win the contest, but one machine captured an international speed record over the 100km closed circuit on 27 August 1939. The F.A.I. Category I aircraft with a speed of 244 m.p.h
Ten of the S.A.I.7 militarised two-seat fighter trainer version appeared during 1943, and the experimental S.A.I.107, S.A.I.207 and S.A.I.403 light fighters were developed from it.
In 1949 S.A.I. Ambrosini placed the S.A.I.7 in full-scale production. The post-war version replaced the 209kW Hirth HM.508D engine of the record-breakers and the 209kW Isotta-Fraschini Beta RC.10 of the wartime version with an Alfa Romeo engine, but apart from improved constructional detail there were few major changes.
Most of the 145 post-war Ambrosini S.7s, some of them completed in single-seat configuration, formed the equipment of various flight training centres attached to the Aeronautica Militare zone headquarters. The military service was terminated in 1956
The S.7 participated in numerous competitions and Leonardo Bonzi established international records over the 100km and 1000km distances on 21 December 1951, with average speeds of 367.36km/h and 358.63km/h respectively.
Engine: Hirth HM.508D, 209kW (280-hp)
Engine: Isotta-Fraschini Beta RC.10, 209kW (280-hp)
Engine: 1 x Alfa Romeo 115ter, 168kW
Take-off weight: 1317 kg / 2904 lb
Empty weight: 1105 kg / 2436 lb
Wingspan: 8.79 m / 28 ft 10 in
Length: 8.17 m / 26 ft 10 in
Height: 2.8 m / 9 ft 2 in
Wing area: 12.8 sq.m / 137.78 sq ft
Max. speed: 358 km/h / 222 mph
Cruise speed: 264 km/h / 164 mph
Ceiling: 5250 m / 17200 ft
Range: 1000 km / 621 miles