Isken was born on 15 April 1918 in Hagendingen, at the time in the district of Metz in the Bezirk Lothringen (German Lorraine) of the German Empire. Today Hagendingen is Hagondange in north-eastern France.[1] Isken was posted to the III. Gruppe (3rd group) of Jagdgeschwader 77 (JG 77—77th Fighter Wing) in mid-1940 where he was assigned to the 7. Staffel (7th squadron).[2] The Staffel had been newly formed on 9 August 1940 and was placed under the command of OberleutnantWolfdieter Huy.[3] On 7 September, III. Gruppe moved to an airfield at Neuruppin. Initially, the Gruppe was equipped with both Messerschmitt Bf 109 E aircraft as well as captured French Curtiss P-36 Hawk fighters. The Gruppe flew the P-36 until 29 October.[4]
On 6 November 1941, Isken's Bf 109 F-4 was hit in oil cooler by anti-aircraft artillery resulting in a forced landing near Belobek.[5] On 15 January 1942, he made an emergency landing in his Bf 109 F-4 (Werknummer 7138—factory number) at Grammatikowo located near Sovietskyi and was injured in the process.[6]
Mediterranean Theater
On 23 October 1942, the British Eighth Army launched the Second Battle of El Alamein. Preceding this attack, the Luftwaffe had already planned to replace Jagdgeschwader 27 (JG 27—27th Fighter Wing), which had been fighting in North African theater, with JG 77.[7] In preparation for this rotation, III. Gruppe of JG 77 was moved to Munich on 19 October where it was equipped with the Bf 109 G-2/trop. On 23 and 24 October, the Gruppe moved to Bari in southern Italy.[8] The Gruppe then relocated to Tobruk Airfield on 26 October.[9] The following day, the Gruppe moved to an airfield at Tanyet-Harun.[10]
On 12 August 1944, the USAAF XII Tactical Air Command, supported by elements of the RAF, attacked German radar installations in the area of the French Riviera. Defending against this attack, Isken and Obergefreiter Horst Rippert may have shot down the Supermarine Spitfire fighter MJ442 from the No. 232 Squadron piloted by Lieutenant Geoffrey W. Dibb.[12]
According to US historian David T. Zabecki, Isken was credited with 56 aerial victories.[14] Obermaier also lists him with 56 aerial victories, 16 on the Eastern Front and 40 on Western Front, including 17 four-engined heavy bombers, claimed in 946 combat missions.[1] Mathews and Foreman, authors of Luftwaffe Aces — Biographies and Victory Claims, researched the German Federal Archives and found documentation for more than 44 aerial victory claims, plus two further unconfirmed claims. This number includes more than 19 on the Western Front, including two four-engined heavy bombers, and 25 on the Eastern Front.[15]
Victory claims were logged to a map-reference (PQ = Planquadrat), for example "PQ 9876". The Luftwaffe grid map (Jägermeldenetz) covered all of Europe, western Russia and North Africa and was composed of rectangles measuring 15 minutes of latitude by 30 minutes of longitude, an area of about 360 square miles (930 km2). These sectors were then subdivided into 36 smaller units to give a location area 3 km × 4 km (1.9 mi × 2.5 mi) in size.[16]
Chronicle of aerial victories
This and the – (dash) indicates unconfirmed aerial victory claims for which Isken did not receive credit.
This and the ? (question mark) indicates information discrepancies listed by Prien, Stemmer, Rodeike, Balke, Bock, Mathews and Foreman.
Claim
Date
Time
Type
Location
Claim
Date
Time
Type
Location
– 7. Staffel of Jagdgeschwader 77 –[17] Operation Barbarossa — 22 June – 5 December 1941
According to Prien, Balke, Stemmer and Bock, pilots of IV. Gruppe of JG 53 claimed three Republic P-47 Thunderbolt fighters shot down near Donaueschingen on 22 December 1944. Two of these P-47 fighters may be the two missing aerial victories claimed by Isken.[35] These claims are not documented by Mathews and Foreman.[30]
– 13. Staffel of Jagdgeschwader 53 – Claims without a location and date in 1945
According to Prien, Isken claimed five aerial victories in March 1945, among them two Republic P-47 Thunderbolt fighters on one day. In April 1945, Isken claimed his 56th aerial victory over a Boeing B-17 Flying Fortress bomber.[36] These claims are not documented by Mathews and Foreman.[30]
^ abcThis claim is not listed by Prien, Stemmer, Rodeike and Bock but is listed by Mathews and Foreman. However, Prien, Stemmer, Rodeike and Bock state that in total twelve aerial victories were claimed by unknown pilots of III. Gruppe.[29]
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Mathews, Andrew Johannes; Foreman, John (2015). Luftwaffe Aces — Biographies and Victory Claims — Volume 2 G–L. Walton on Thames: Red Kite. ISBN978-1-906592-19-6.
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Patzwall, Klaus D. (2008). Der Ehrenpokal für besondere Leistung im Luftkrieg [The Honor Goblet for Outstanding Achievement in the Air War] (in German). Norderstedt, Germany: Verlag Klaus D. Patzwall. ISBN978-3-931533-08-3.
Prien, Jochen (1991). Pik-As: Geschichte des Jagdgeschwaders 53 — 3 — Das Ende in Italien 1944, Rumänien, Ungarn 1944/45, Einsatz zur Verteidigung des Reiches 1943–1945 [Ace of Spades: History of the Fighter Wing 53 — 3 — The End in Italy 1944, Romania, Hungary 1944/45, Defense of the Reich 1943–1945] (in German). Eutin, Germany: Struve-Druck. ISBN978-3-923457-16-8.
Prien, Jochen (1992). Geschichte des Jagdgeschwaders 77—Teil 1—1934–1941 [History of Jagdgeschwader 77—Volume 1—1934–1941] (in German). Eutin, Germany: Struve-Druck. ISBN978-3-923457-19-9.
Prien, Jochen (1994). Geschichte des Jagdgeschwaders 77—Teil 3—1942–1943 [History of Jagdgeschwader 77—Volume 3—1942–1943] (in German). Eutin, Germany: Struve-Druck. ISBN978-3-923457-26-7.
Prien, Jochen; Stemmer, Gerhard; Rodeike, Peter; Bock, Winfried (2003). Die Jagdfliegerverbände der Deutschen Luftwaffe 1934 bis 1945—Teil 6/II—Unternehmen "BARBAROSSA"—Einsatz im Osten—22.6. bis 5.12.1941 [The Fighter Units of the German Air Force 1934 to 1945—Part 6/II—Operation "BARBAROSSA"—Action in the East—22 June to 5 December 1941] (in German). Eutin, Germany: Struve-Druck. ISBN978-3-923457-70-0.
Prien, Jochen; Stemmer, Gerhard; Rodeike, Peter; Bock, Winfried (2004). Die Jagdfliegerverbände der Deutschen Luftwaffe 1934 bis 1945—Teil 8/II—Einsatz im Mittelmeerraum—November 1941 bis Dezember 1942 [The Fighter Units of the German Air Force 1934 to 1945—Part 8/II—Action in the Mediterranean Theater—November 1941 to December 1942] (in German). Eutin, Germany: Struve-Druck. ISBN978-3-923457-74-8.
Prien, Jochen; Stemmer, Gerhard; Rodeike, Peter; Bock, Winfried (2005). Die Jagdfliegerverbände der Deutschen Luftwaffe 1934 bis 1945—Teil 9/I—Winterkampf im Osten—6.12.1941 bis 30.4.1942 [The Fighter Units of the German Air Force 1934 to 1945—Part 9/I—Winter War in the East—6 December 1941 to 30 April 1942] (in German). Eutin, Germany: Struve-Druck. ISBN978-3-923457-76-2.
Prien, Jochen; Stemmer, Gerhard; Rodeike, Peter; Bock, Winfried (2006). Die Jagdfliegerverbände der Deutschen Luftwaffe 1934 bis 1945—Teil 9/III—Vom Sommerfeldzug 1942 bis zur Niederlage von Stalingrad—1.5.1942 bis 3.2.1943 [The Fighter Units of the German Air Force 1934 to 1945—Part 9/III—From the 1942 Summer Campaign to the Defeat at Stalingrad—1 May 1942 to 3 February 1943] (in German). Eutin, Germany: Struve-Druck. ISBN978-3-923457-78-6.
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Prien, Jochen; Balke, Ulf; Stemmer, Gerhard; Bock, Winfried (2019). Die Jagdfliegerverbände der Deutschen Luftwaffe 1934 bis 1945—Teil 13/V—Einsatz im Reichsverteidigung und im Westen—1.1. bis 31.12.1944 [The Fighter Units of the German Air Force 1934 to 1945—Part 13/V—Action in the Defense of the Reich and in the West—1 January to 31 December 1944] (in German). Eutin, Germany: Struve-Druck. ISBN978-3-942943-21-5.
Prien, Jochen; Stemmer, Gerhard; Bock, Winfried; Balke, Ulf (2020). Die Jagdfliegerverbände der Deutschen Luftwaffe 1934 bis 1945—Teil 13/VI—Einsatz im Reichsverteidigung und im Westen—1.1. bis 31.12.1944 [The Fighter Units of the German Air Force 1934 to 1945—Part 13/VI—Action in the Defense of the Reich and in the West—1 January to 31 December 1944] (in German). Eutin, Germany: Struve-Druck. ISBN978-3-942943-22-2.
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Shores, Christopher; Massimello, Giovanni (2016). A History of the Mediterranean Air War, 1940–1945. Volume Three: Tunisia and the End in Africa, November 1942–1943. London, UK: Grub Street Publishing. ISBN978-1-910690-67-3.
Shores, Christopher; Massimello, Giovanni; Guest, Russell; Olynyk, Frank; Bock, Winfried; Thomas, Andrew (2021). A History of the Mediterranean Air War 1940–1945: Volume Five: From the Fall of Rome to the End of the War 1944–1945. London: Grub Street. ISBN978-1-911621-97-3.