it was subordinated to Jagdgeschwader 52 (JG 52—52nd Fighter Wing) and tasked with patrolling the Upper Rhine region during the Phoney War phase of World War II. On 11 May 1940, the second day of the Battle of France, II. Gruppe flew ground attack missions in the Alsace region. Following the German advance into Belgium and France, 6. Staffel was moved to Dinant on 26 May. That day, remnants of the French Army and the British Expeditionary Force (BEF) were retreating towards Dunkirk. To save the BEF, the British under the cover of the Royal Air Force (RAF), had launched Operation Dynamo. On 28 May, Huppertz claimed his first aerial victory. He was credited with shooting down a Supermarine Spitfire fighter over the Dunkirk battle zone. For this achievement, Huppertz was awarded the Iron Cross 2nd Class () on 30 May 1940. In July 1940, the Luftwaffe began a series of air operations dubbed Kanalkampf (Channel Battle) over the English Channel against the RAF, which marked the beginning of the Battle of Britain. On 7 July, Huppertz claimed his second aerial victory, a Spitfire shot down northwest of Dungeness. On 5 October, II. Gruppe moved to an airfield at Mardyck, west of Dunkirk. Four days later, Huppertz received the Iron Cross 1st Class (). He claimed his third aerial victory on 25 October, a Hawker Hurricane fighter shot down near Tunbridge Wells. On 20 October, Huppertz claimed a Spitfire fighter on a mission to London. His last aerial victory in 1940 was claimed on 14 November when he shot down another Spitfire fighter over the Thames Estuary. On 21 November, Huppertz was injured in a forced landing near Gravelines. The accident was caused by engine problems of his Messerschmitt Bf 109 E-1 (Werknummer 6199—factory number). On 7 December, II. Gruppe was sent to Mannheim-Sandhofen for a period of replenishment and rest. On 14 February 1941, the Gruppe returned to Mardyck on the Channel Front. There, Huppertz claimed a Spitfire fighter shotdown near Dungeness on 11 March. II. Gruppe of JG 51 was withdrawn from the Channel Front in early June 1941 and ordered to Dortmund where the unit was reequipped with the Bf 109 F series. Operation Barbarossa On 15 June, IV. Gruppe of JG 51 began transferring east and was located at an airfield named Krzewicze, located approximately west of Brest-Litovsk. On 22 June, German forces launched Operation Barbarossa,