After conversion training to the Me 262 jet fighter, he was appointed commander of I. Gruppe of Jagdgeschwader 7 "Nowotny" (JG 7—7th Fighter Wing), the first operational jet fighter wing in the world, in November 1944. Promoted to Major (major), he took command of JG 7 "Nowotny" as a Geschwaderkommodore in January 1945, a position he held until the end of hostilities.