From May 1938, production Potez 630 fighters started to be delivered; the first improved Potez 631 aircraft were received in August that year. Potez 630 and 631s, in two-seater configuration, were soon used to replace obsolete ANF Les Mureaux 113 used as night fighters, while single-seat fighter groups received a number of three seat Potez 63s to act as command aircraft, from which formations of single-seat fighters would be directed and co-ordinated by radio. In July 1938, the first fifteen Potez 630 aircraft participated in the Villacoublay Air Show.