Société nationale des constructions du Midi SNCAM
Dewoitine D.520 "WW2"

The Dewoitine D.520 is a French fighter aircraft that entered service in early 1940, shortly after the beginning of the Second World War. The D.520 was designed in response to a 1936 requirement from the French Air Force for a fast, modern fighter with a good climbing speed and an armament centred on a 20 mm cannon. At the time the most powerful V-12 liquid-cooled engine available in France was the Hispano-Suiza 12Y, which was less powerful, but lighter than contemporary engines such as the Rolls-Royce Merlin and Daimler-Benz DB 601. Other fighters were designed to meet the specifications but none of them entered service, or entered service in small numbers, too late to play a significant role during the Battle of France.

Following the armistice of 1940, the D.520 continued to be used, being operated by both the Free French Air Force and the Vichy French Air Force..

Armament

Production-standard armament consisted of a 20 mm (0.787 in) HS.404, which had an ammunition capacity of 60 rounds, firing through the propeller hub, and four belt-fed MAC 1934 M39 7.5 mm (0.295 in) machine guns in the wings, with 675 rounds per gun. The MAC 1934 machine guns had a high rate of fire of 1,200 rounds per minute (rpm), while the HS.404 had an effective rate of fire of 600 rpm and was accurate up to 500 m (1,600 ft); the ammunition capacity meant that the machine guns could be fired for a total of 30 seconds, while the cannon had ten seconds' worth of ammunition.