IMAM Ro.57

 

The Ro.57 was preceded by another twin-engine fighter design, the Ro.53, which never entered production. The Ro.57 consisted of an all metal, semi-monocoque fuselage with a steel skeleton and Duralumin structure. The wings were also Duralumin.

Powered by two 840 hp Fiat A.74 radial engines giving a maximum speed of 516 km/h, which in 1939 was better than that of the main Italian fighter, the Macchi C.200 (504 km/h). After testing at Guidonia it was proposed by IMAM for use as a dive bomber. This transformation, which involved the addition of dive brakes, provision for 500 kg bombs and an improved forward firing armament (adding two 20 mm cannon), took time and delayed production. The resulting aircraft was designated the Ro.57bis. Performance dropped to 457 km/h maximum speed and to 350 km/h at cruise speed. The Ro.57bis was ordered into production in 1942 and entered service with the 97 Gruppo in 1943. About 50-60 aircraft were delivered.

It is said that the Ro.57 could had been the long range interceptor that Italy lacked throughout the war. It proved to be too costly for the limited weapons it carried and it never was assigned a clear role

Two hundred aircraft were ordered, but only about 75 were produced in two versions, one flown as an interceptor, the other in the role of a ground attack aircraft.

An improved version of the Ro. 57, the Ro. 58 first flew in 1942 and was among Italy's first twin--engined machines to make use of 0.8.601 engines with speed capabilities in the region of 600 km/h, a rather remarkable performance for a heavy combat and attack machine. Also its armament, unlike its predecessor, was increased by the adoption of five 20 mm MG 151/20 cannon and one 12.7 mm SAFAT machine-gun. Featuring a brilliant performance in 1943 it was the recipient of a production order for 50 machines that, however, were never built.

General characteristics

Crew: One

Length: 8.80 m (28 ft 10½ in)

Wingspan: 12.50 m (41 ft 0 in)

Height: 2.90 m (9 ft 6in)

Wing area: 23.0 m² (248 ft²)

Empty weight: 3,497 kg (7,694 lb)

Loaded weight: 5,000 kg (11,000 lb)

Powerplant: 2— Fiat A.74 R.C.38 14-cylinder air-cooled radial engines, 627 kW (840 hp) each

Performance

Maximum speed: 501 km/h (270 kts, 311 mph) at 5,000 m (16,400 ft)

Cruise speed: 390 km/h (210 kts, 242 mph)

Range: 1,200 km (648 nm, 745 mi)

Service ceiling 7,800 m (25,590 ft)

Wing loading: 217 kg/m² (44.4 lb/ft²)

Power/mass: 0.25 kW/kg (0.15 hp/lb)

Climb to 6,000 m (19,700 ft): 9 min 30 sec