The D.501 was a development of the D.500 with considerably more powerful armament. The two fuselage-mounted machine guns were removed, and the adoption of the Hispano-Suiza 12Xcrs engine, rated identically to the Hispano-Suiza 12Xbrs of the D.500, allowed the introduction of a moteur-canon installation in which a 20 mm Hispano-Suiza (Oerlikon) S7 cannon was fitted between the two cylinder banks of the V-12 engine to fire through the hollow propeller shaft. This version was accepted for French service with the designation D.501C.1, and production totalled 177 aircraft built by Dewoitine, Lioré-et-Olivier and Loire: 163 were delivered for French service (133 to the air force and 30 to the naval air arm) and the other 14 for Lithuanian service with the designation D.501L.
Type Single seat fighter
Engine 1 Hispano-Suiza 12Xcrs l
Dimensions Length  7,56 m, height 2,70 m ,  span 12,09 m , wing area 16,50 m 
Weights Empty 1287 kg, loaded 1787 kg , max. take off weight  
Performance Max.. speed 367 km/h at 5000 m, 315 km/h at sea level , cruising speed 225 km/h , range 870 km , endurance  , service ceiling  10200 m , climb to 1000 m1 min. 21 sec.
Armament One 20 mm Hispano-Suiza (Oerlikon) S7 fixed forward-firing cannon with 60 rounds in a Engine mounted installation to fire through the hollow propeller shaft, and two 7.5 mm Darne fixed forward-firing machine guns in the leading edges of the wing