The aircraft had a fixed undercarriage and the aircraft was powered by a Gnome-Rhône 14M05 Mars, a 14-cylinder radial engine with a maximum of 760 hp (567 kW), with a fuel tank holding 350 litres (77 imp gal; 92 US gal). Work on the aircraft was temporarily stopped but later resumed in 1938. The design was finished in 1938, and the first model was made in February 1939 with technical documentation completed in June of that year. A second prototype was designed to have retractable landing gear. It was a single-seat all-metal fighter aircraft and had a closed cockpit. The aircraft was also designed to be equipped with 4 machine guns (2 wing-mounted and 2 in the hull), though the prototype was not armed.