Cross of the Iron Cross (), the first pilot of III. Gruppe to receive the distinction. He had qualified for this distinction after 40 aerial victories. The presentation was made by General der Flieger Kurt Pflugbeil. By the end of 1941, his total number of aerial victories had increased to 62, making him the most successful fighter pilot of III. Gruppe. Oak Leaves and death Köppen claimed four aircraft shot down on 24 February 1942, and was decorated with Knight's Cross of the Iron Cross with Oak Leaves () after 72 aerial victories on 27 February 1942. He was the second non-commissioned officer and 79th member of the Wehrmacht to be so honored. The presentation was made by Adolf Hitler, who also promoted him to Leutnant effective as of 1 April 1942. On 29 April, III. Gruppe had relocated to Zürichtal, a small village at the Inhul in the former German settlement west of Feodosia in the Crimea. On 1 May, the Gruppe was subordinated to VIII. Fliegerkorps and was supporting the 11th Army in the Battle of the Kerch Peninsula. The next day, Köppen became an "ace-in-a-day", claiming five Soviet fighter aircraft shot down. Following combat with a Petlyakov Pe-2 on 5 May, Köppen was posted as missing in action flying Messerschmitt Bf 109 F-4 "white 4" (Werknummer 7303—factory number) north of Ak-Monai (present-day Kam'yans'ke) near the Arabat Fortress. He was last seen swimming in the Sea of Azov when Soviet boats closed in on him. Feldwebel Alfred Grislawski made a strafing attack on these boats. Köppen was officially declared dead on 30 May 1969 by a court in Dillingen. His brother, Eckhardt Köppen, was killed in action on 15 January 1945; he was posthumously awarded the Knight's Cross on 15 March 1945. Summary of career Aerial victory claims According to US historian David T. Zabecki, Köppen was credited with 86 aerial victories. Spick lists Köppen with 85 aerial victories claimed in an unknown number of combat missions. All of his victories were recorded over the Eastern Front. Mathews and Foreman, authors of Luftwaffe Aces – Biographies and Victory Claims, researched the German Federal Archives and found documentation for 85 aerial victory claims, all of which claimed on the Eastern Front. Awards Front Flying Clasp of the Luftwaffe Iron Cross (1939) 2nd Class 1st Class Honour Goblet of the Luftwaffe on 17 November 1941 as Feldwebel and pilot German