Rheine area. Defending against this attack, Glunz claimed a B-17 shot down at 09:05 near Hagen and a second B-17 at 09:28 west of Mönchengladbach. During the Schweinfurt-Regensburg mission on 17 August 1943, Glunz shot down a B-17 bomber of the 305th Bombardment Group northwest of Schouwen, crashing at Averbode. That day, Gruppenkommandeur Galland was killed in action. Galland was temporarily succeeded by Hauptmann Johannes Naumann until Oberstleutnant Johannes Seifert took command on II. Gruppe on 9 September. Two days later, Glunz claimed a Martin B-26 Marauder bomber from the 323d Bombardment Group (Medium) shot down over northern France. The claim was not confirmed. On 29 August, Glunz received the Knight's Cross of the Iron Cross (), the only non-commissioned pilot of JG 26 to receive this distinction. On 31 August, VIII Bomber Command targeted the airfields of Luftflotte 3 (Air Fleet 3). Defending against this attack, Glunz shot down a B-17 from the 303rd Bombardment Group near Le Tréport. He then went on home leave in September. On 1 October, as part of the group expansion from three Staffeln per Gruppe to four Staffeln per Gruppe, Glunz's 4. Staffel under the command of Leutnant Helmut Hoppe was renamed to 5. Staffel. Two days later, he claimed an aerial victory over Spitfire which belonged to either No. 341 or No. 485 Squadron. The claim was not confirmed. A week later on 10 October, he shot down a 100th Bombardment Group (Heavy) B-17 bomber north of Deelen. The bomber was on a mission to bomb Münster. On 14 October, during the second Schweinfurt raid also called "Black Thursday", Glunz claimed an unconfirmed aerial victory over an escorting P-47 of the 353rd Fighter Group near Budel. VIII Bomber Command again sent its bombers to Münster on 11 November. II. Gruppe encountered unescorted B-17 bombers of the 94th Bombardment Group (Heavy) near Dordrecht in the Netherlands. Glunz claimed two B-17 bombers shot down, only one was later confirmed. On 26 November, the USAAF sent 633 bombers of VIII Bomber Command to targets at Bremen and Paris. Defending against this attack, Glunz shot down an escorting P-47 fighter from the 78th Fighter Group near Chantilly. That day, II. Gruppe lost its Gruppenkommandeur when Seifert was killed in action. He was replaced by Hauptmann Wilhelm Gäth. On 1 December, Hoppe, the commanding officer of 5. Staffel, was also killed in action. In consequence, Hauptmann Johann