Caproni Sauro-1

Caproni

Industry	Aerospace
Headquarters	Taliedo , Italy

The Caproni Sauro-1 (meaning Sorrel in English), also known as the Caproni Tricap, was a lightweight, single-engine cantilever monoplane designed for two occupants seated in tandem. Constructed in Italy during the early 1930s, it was intended for touring purposes. Although it demonstrated commendable performance and received positive evaluations during testing, only a single example was ever produced.

Design and development

Although produced by Caproni, the Sauro-1 originated from a design by Emmanuele Trigona, which accounts for its alternative designation, Tricap (combining Trigone and Caproni). The aircraft featured an aerodynamically refined cantilever monoplane configuration with a distinctive low-set inverted gull wing. Its wings exhibited a substantial thickness and broad chord at the root, gradually tapering in both planform and thickness toward smoothly rounded wing tips. The structure incorporated both wood and chrome steel framing, covered by a combination of plywood and fabric. The plywood on the wings served a load-bearing function. A camber adjustment mechanism linked the neutral position of the ailerons to the angle of incidence of the tailplane, while the ailerons themselves maintained their standard opposing movements to control lateral flight dynamics. The fixed, conventional undercarriage utilized the inverted gull wing’s lowest points to mount the main landing gear legs, resulting in shorter struts and a wider track. These legs and portions of the main wheels were enclosed within shallow, full-chord fairings, and featured rubber shock absorbers and braking systems.

Propulsion was provided by a 97 kW (130 hp) Farina T-58 radial engine housed within a domed cowling that left each of its five cylinders exposed individually. The fuselage behind the powerplant had an ovoid cross-section and tapered gradually toward the tail. Constructed with a chrome steel frame covered in plywood and fabric, it accommodated two tandem cockpits: the forward cockpit positioned above the wing and the rear cockpit just aft of its trailing edge. Both cockpits were equipped with long headrest fairings extending rearward to the tail section. Dual controls were installed, with the forward cockpit's controls capable of being disengaged during flight. Each seat provided sufficient space for a parachute. The tail assembly was conventional in layout, featuring steel frames covered with both aluminium and fabric materials. The tapered tailplane was mounted mid-fuselage, supporting an angular vertical fin and rudder above it. The rudder’s upper edge was shaped to allow clearance for elevator movement. A tailskid fitted with rubber suspension and steel reinforcement was affixed at the rear end of the fuselage.

Manufactured at Caproni's principal facility in Taliedo, the Sauro underwent testing at Guidonia Montecelio under military registration. Despite its successful handling characteristics and performance metrics, no further development or production ensued. Elements of its design were later incorporated by Trigona into a fighter aircraft concept; however, this project was discontinued in 1943.