Designed as a two-seat light training and touring monoplane, the Ambrosini S.A.I.3 had long-span elliptical wings, a deep rear fuselage and a fixed tailwheel type landing gear. The chosen powerplant was either a 63kW Fiat A.50 radial or 97kW Alfa Romeo A.110 inverted inline piston engine, the latter enclosed within a close cowling. Small batches of the S.A.I.3 were built, some of them with an enclosed cabin in place of the more common tandem open cockpits. The more powerful Alfa Romeo-engined model had superior performance, despite a maximum take-off weight increase by 40kg to 830kg; maximum speed rose to 230km/h, service ceiling to 5200m and range to 680km.
S.A.I.3 Engine: 1 x Fiat A.50 piston engine, 63kW Take-off weight: 790 kg / 1742 lb Empty weight: 550 kg / 1213 lb Wingspan: 10.45 m / 34 ft 3 in Length: 7.05 m / 23 ft 2 in Height: 2.8 m / 9 ft 2 in Wing area: 14 sq.m / 150.69 sq ft Max. speed: 200 km/h / 124 mph Cruise speed: 170 km/h / 106 mph Ceiling: 4000 m / 13100 ft Range: 620 km / 385 miles