France, Germany, Greece, Romania, and Switzerland used the Potez 63 series. Romania and Greece received some of the Potez 633s before the outbreak of World War II.
- Potez 631, day fighters: Groupes de Chasse de Nuit GC II/8
- Potez 631, night fighters: Groupes de Chasse de Nuit GCN III/1, Groupes de Chasse de Nuit GCN II/4, Groupes de Chasse de Nuit GCN I/13, Groupes de Chasse de Nuit GCN II/13
88 of the Potez 631 night fighters were delivered by April 1, 1939. By September that had increased to 206.
First Shot Down
On September 8, 1939, a Potez 637 was the first Allied aircraft lost on the Western Front.
From May 10 - 21, 1940, the Flotille F1C destroyed twelve German aircraft with eight losses of their own. After this the night fighters were moved to daytime ground attacks.
There was a similar resemblance to the German Bf 110, and the Potez 63s were shot at by French and English fighters. Some say as many as 30 were shot down because of mistaken identity.
By June 1940, out of 1,115 delivered to units, only 663 survived. Of these 251 were in North Africa. Over 200 Potez 63.11s were lost in the initial few weeks.
The Potez 631 night fighters shot down only 29 German aircraft while sustaining 93 losses.
After the Armistice production of the Potez 63.11 continued and these were used for training by the Germans.