The Fiat CR.5 was a version of the CR.1 biplane that was powered by a licence-built Jupiter radial engine. The Bristol Jupiter had been developed towards the end of the First World War as the Cosmos Jupiter. Cosmos Engineering went bankrupt in 1920 and was taken over by Bristol, where work continued on the design, eventually turning it into a very reliable aircraft engine that was produced under licence in fourteen countries. In Italy the engine was produced by Alfa Romeo, first as the Alfa Romeo Jupiter (420hp), and later as the Alfa Romeo 126-RC35 (650hp).
The original CR.1 was powered by a 300hp Hispano-Suiza inline engine, and was a rather unusual sesquiplane with a larger lower and smaller upper wing. The CR.5 retained this basic configuration, but was powered by the Alfa Romeo Jupiter engine. The CR.1 was also used to test the Armstrong Siddeley Lynx radial (CR.2) and Fiat A.20 inline engine (CR.10), before development moved onto the much more modern Fiat CR.20.