 He was replaced as commander of JG 51 by Werner Mölders on 23 July with the latter formally taking command on the 27th of July.Promoted to "Generalmajor", Osterkamp was awarded his Knight's Cross of the Iron Cross on 22 August 1940.Following his replacement in JG 51, Osterkamp was appointed "Jagdfliegerführer 2", the commander of fighter aircraft in Luftflotte 2.