During the late 1960s, the Spanish Air Force was still operating a number of outdated piston-engined transports, including the three-engined Junkers Ju 52 and two-engined Douglas C-47. In order to meet the Spanish Air Force's needs to modernise its transport force, CASA proposed the C-212, a twin engined 18 seat transport aircraft that would be capable of fulfilling a variety of military roles, including passenger transport, ambulance aircraft and paratroop carrier, while also being suitable for civil use. The first prototype flew on 26 March 1971. In 1974, the Spanish Air Force decided to acquire the Aviocar to update its fleet.