Dewoitine D.520 in French Service
The Dewoitine D.520 entered frontline service in early 1940, with Groupe de Chasse I/3 becoming the first operational user. Initial deliveries in January were unarmed and used for conversion training. Combat-standard aircraft began arriving in April and May 1940; 34 such airframes reached frontline units before major operations commenced. Pilots and maintenance crews judged the type favourably, noting its responsiveness and generally sound handling. Comparative trials on 21 April 1940 at CEMA against a captured Messerschmitt Bf 109E-3 highlighted the D.520’s strengths and weaknesses. The German fighter held a roughly 32 km/h speed margin due to its more powerful engine, and its automatic leading-edge slats allowed it to sustain tight turns near the stall. The Dewoitine, however, matched the Bf 109’s turn radius and displayed superior maneuverability, albeit with hazardous departure characteristics: during trials it repeatedly spun out of turning manoeuvres.
When Germany launched its offensive on 10 May 1940, production totalled 246 aircraft, yet only 79 had been formally accepted by the Armée de l’Air. Many others were undergoing retrofit to the latest configuration. Consequently, GC I/3 was the only fully-equipped unit, with 36 combat-ready fighters. It engaged the Luftwaffe immediately, downing several reconnaissance and bomber aircraft from 13 May onward without initial losses. On 14 May the unit suffered its first combat attrition—two aircraft—while claiming ten confirmed victories across multiple Luftwaffe types, including Bf 109s, Bf 110s, He 111s, and Do 17s.
Additional Groupes de Chasse converted during the rapid escalation of the campaign, including GC II/3, III/3, III/6, and II/7, as well as the naval 1er Flotille de Chasse. Only GC I/3, II/7, II/6, and naval AC 1 saw significant action before the French capitulation; some units converted too late to participate meaningfully. A few Dewoitines were also flown by non-operational formations and by Polish and civilian volunteer pilots for airfield defence around Toulouse.
In total, Dewoitine units claimed 114 confirmed victories and 39 probables—mostly against Italian aircraft—at the cost of 85 losses. By the June 1940 armistice, 437 D.520s had been completed, of which 351 had reached the Air Force. Many escaped capture: 165 flew to North Africa, with several Groupes transferring intact to Algeria; three aircraft from GC III/7 reached Britain and joined Free French forces; and 153 remained in Vichy-controlled metropolitan territory.
