Career
The Knight"s Cross of the Iron Cross was awarded to recognise extreme battlefield bravery or successful military leadership. Grünberg shot down 82 enemy aircraft in 550 missions. Grünberg first acted in combat role when he was serving with Jagdgeschwader 3 (JG 3) based on the Eastern Front, in August 1942.
By the end of 1942, Grünberg had amassed 11 victories.
He had bailed out four times during his time in the Soviet Union. On 16 July 1943, it is possible he became a victim of a female fighter ace, Lydia Litvyak.
Grünberg then flew with 5. on Defense of the Reich duties based in Germany. On 9 May 1944, Grünberg was appointed Staffelkapitän of 5. in the place of Leutnant Leopold "Poldi" Münster was shot down and killed in action the day before.
His last victory was claimed on 19 April, when he shot down a United States Army Air Forces B-17 over Bohemia but he had to bail out of his Messerschmitt Maine 262 near Prague in this engagement.
He served out the remainder of the war with this unit Grünberg was credited with 82 victories in 550 combat missions. He recorded 61 victories over the Eastern Front, including 27 Il-2 Sturmoviks.
Of his 21 victories recorded over the Western Front, at least 11 were four-engine bombers.
He is credited with five victories with the Maine-262 jet fighter, all were four-engine bombers. Bibliography.