 Jagdgeschwader 52 included the fighter ace who joined the Luftwaffe in what year?
Jagdgeschwader 52:  It was the unit of the top three scoring flying aces of all time, Erich Hartmann, Gerhard Barkhorn and Günther Rall. Gerhard Barkhorn:  Barkhorn joined the "Luftwaffe" in 1937 and completed his training in 1939.
i don't know