While perfecting the series-produced Dewoitine D.520 fighters, designers also worked to create new models of the same plane. In November 1939, work began on creating the Dewoitine D.521 model, equipped with the British liquid-cooled V12 Rolls-Royce Merlin Mk.III engine with a rated output of 1,030 hp. It was suggested that a fighter fitted with this engine could reach a maximum horizontal speed of 570 km/h.
Since an engine-mounted cannon could not be installed on the Rolls-Royce Merlin engine, two Hispano-Suiza H.S.404 cannons were mounted on the wings instead. This meant that all the Dewoitine D.521's weaponry was mounted on the wings, and consisted of two 20 mm Hispano-Suiza HS.404 drum magazine cannons with 60 shells each and four 7.5 mm Chatellerault MAC 1934 machine guns with 675 rounds each.
Note that precise information (primarily photographs) on the practical configuration of the Dewoitine D.521's Hispano-Suiza wing-mounted cannons is not available. For this reason, we can only make educated guesses about the fighter's armament structure.
The main purpose, usage and tactics recommendations
Pros and cons of the plane
History of creation and combat usage
Screenshots and fan art
|Max speed||568.8km/h on altitude 6500m|
|Take on distance||310m|
|Climb time||415s to altitude 5000m|