Originally designated the M 37, the aircraft was designed as a four-seat sports/recreation aircraft for competition in the 4th Challenge International de Tourisme (1934).[2][3] The M 37 prototype flew first in spring 1934, powered by a 250 PS (247 hp, 184 kW) Hirth HM 8U 8.0 litre displacement, air-cooled inverted-V8 engine, which drove a three-blade propeller.