Born in Braunschweig, Waldmann volunteered for service in the Luftwaffe in 1940. After training at various pilot and fighter-pilot schools, he was posted to "Jagdgeschwader" 52 (JG 52—52nd Fighter Wing), operating on the Eastern Front, in August 1942. Here Waldmann fought in the aerial battles over Stalingrad, the Caucasus, the Black Sea, and the Crimea. He was credited with 84 aerial victories before briefly being transferred to the Western Front, where he was credited with one aerial victory. Back on the Eastern Front, Waldmann accumulated further victories, bringing his score to 125 victories by end of May 1944. He then fought in the skies over France after the Western Allied Invasion of Normandy, claiming seven aerial victories, before converting to the Messerschmitt Me 262 jet fighter in late 1944. Flying the Me 262, Waldmann shot down two North American P-51 Mustangs on 22 February 1945 before being killed in a mid-air collision with one of his squadron members on 18 March 1945 near Schwarzenbek, Holstein.