Gruppe (3rd group).[16] On 10 May 1940 Fall Gelb began, and JG 52 supported German forces in the invasion of Belgium and Battle of France. On the third day of the campaign, 12 May 1940, Rall achieved his first victory. Three French Curtiss H75-C1 fighters were attacking a German reconnaissance aircraft at a height of 26,000 feet (7,900 m).