The D.513 was a single-seat low-wing cantilever monoplane fighter that first flew on 6 January 1936. The D.513 was powered by a 860hp (641kW) Hispano-Suiza 12Ycrs1 inline piston engine and had a retractable tailwheel landing gear. Testing proved that the D.513 was unstable and not able to reach the expected speeds and it was rebuilt with a new fuselage and a modified tail unit. The changes did not improve the stability or the maximum speed and problems were also found in the engine cooling and landing gear, further development was stopped. The second prototype was modified with landing gear and a radiator from the D.503, it was re-designated the D.514LP and was used in high-speed parachute trials.