Sembill were punished by Hermann Göring personally. On 27 April, II. Gruppe was moved again, this time to an airfield at Katwijk where it started receiving the first aircraft of the Bf 109 F series. Glunz was promoted to Unteroffizier (subordinate officer or sergeant) on 1 May. Flying from Katwijk on 7 May, he claimed his first aerial victory when he shot down a RAF Supermarine Spitfire fighter east of Deal. On 19 May, he was credited with another Spitfire destroyed, claimed at 12:40 north of Dover. This earned him the Iron Cross 2nd Class (), awarded on 26 May and the Iron Cross 1st Class () on 8 June. On 9 June, II. Gruppe of JG 51 was withdrawn from the Channel Front. On 13 June, the Stab and 4. Staffel of JG 52 were ordered east to Suwałki, located about from the southwestern Lithuanian border, while 5. and 6. Staffel were moved to Eastern Prussia. On 22 June, German forces launched Operation Barbarossa, the German invasion of the Soviet Union. At the start of this invasion, II. Gruppe was controlled the Stab of Jagdgeschwader 27 (JG 27—27th Fighter Wing) which was subordinated to VIII. Fliegerkorps (2nd Air Corps) and part of Luftflotte 2 (Air Fleet 2). JG 27 area of operation during Operation Barbarossa was over the northern area of Army Group Center. Glunz claimed his first aerial victory on the Eastern Front in the vicinity of Varėna on 26 June. That day he shot down an Ilyushin DB-3 bomber at 09:33. Glunz received the Front Flying Clasp of the Luftwaffe for fighter pilots in Bronze () on 1 July. Two days later, he claimed two further DB-3 bombers near Barysaw. On 16 July 1941, his Bf 109 F-2 (Werknummer 8175—factory number) suffered engine failure resulting in an emergency landing at Vitebsk. Western Front Glunz joined Jagdgeschwader 26 "Schlageter" (JG 26—26th Fighter Wing) on 18 July 1941 and was assigned to the II. Gruppe. JG 26 was named after Albert Leo Schlageter, a martyr cultivated by the Nazi Party. At the time, II. Gruppe was commanded by Hauptmann Walter Adolph and based at Moorsele Airfield, Belgium near the English Channel. Glunz made his first check flight with this unit on 24 July and flew his first combat mission on 29 July with 4. Staffel. On 6 August, he flew another mission resulting in no claims or losses. On