The Ba.27 was a low-wing braced monoplane with fixed tailwheel undercarriage. As originally designed, the Ba.27 had a fuselage of steel tube construction skinned with light, corrugated alloy metal and wooden wings and tailplane. Evaluation of the two prototypes by the Regia Aeronautica in 1933 was strongly negative, resulting in an extensive redesign of the aircraft. The fuselage shape was made more rounded and the pilot's open cockpit was moved higher and forward to improve visibility. The corrugated skinning was also replaced with smooth sheet metal.
A prototype of this revised version, known as the Metallico, was first flown in June 1934, but Regia Aeronautica's appraisal was only a little more positive.