Power was provided by the Fiat A.74 radial engine, although Castoldi preferred inline engines, and had used them to power all of his previous designs. With "direttiva" (Air Ministry Specification) of 1932, Italian industrial leaders had been instructed to concentrate solely on radial engines for fighters, due to their superior reliability. The A.74 was a re-design of the American Pratt & Whitney R-1830 SC-4 Twin Wasp, performed by engineers Tranquillo Zerbi and Antonio Fessia, and was the only Italian-built engine that could provide a level of reliability comparable to Allied designs. The licence-built A.74 engine could be problematic. In late spring 1941, 4° "Stormo"'s Macchi C.200s then based in Sicily, had all the A.74s produced by the Reggiane factory replaced because they were defective units. The elite unit had to abort many missions against Malta due to engine problems. While some figures considered the Macchi C.200 to have been underpowered, the air-cooled radial engine provided some pilot protection during strafing missions. Consequently, the C.200 was often used as a "cacciabombardiere" (fighter-bomber). Moreover, it was maneuverable and had a sturdy all-metal construction.