The D.513 was a single-seat low-wing cantilever monoplane fighter that first flew on 6 January 1936.

[1] The D.513 was powered by an 860 hp (641 kW) Hispano-Suiza 12Ycrs1 V-12 piston engine and had a retractable tailwheel landing gear.

[1] 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.

[1] The changes did not improve the stability or the maximum speed and problems were also found in the engine cooling and landing gear, and further development was halted.

[1] The second prototype was modified with landing gear and a radiator from the D.503.