Jagdgeschwader 52 included the fighter ace who joined the Luftwaffe in what year?
Gerhard Barkhorn Gerhard "Gerd" Barkhorn (20 March 1919 – 8 January 1983) was the second most successful fighter ace of all time after fellow "Luftwaffe" pilot Erich Hartmann, the two people to ever exceed 300 confirmed victories. Barkhorn joined the "Luftwaffe" in 1937 and completed his training in 1939.
Hermann Greiner Georg-Hermann Greiner (2 January 1920 – 26 September 2014) was a Luftwaffe night fighter ace who served during World War II. Greiner was recipient of the Knight's Cross of the Iron Cross with Oak Leaves—the fourth highest German award by war's end. He was also a squadron commander in the prestigious "Nachtjagdgeschwader" 1 ("NJG" 1—Night Fighter Wing 1), the most successful night fighter interceptor unit of any nation in the history of aerial warfare.