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-Friedrich Joppien Hermann-Friedrich Joppien (19 July 1912 – 25 August 1941) was a German fighter pilot during World War II. A fighter ace, he was credited with 70 enemy aircraft shot down in roughly 270 combat missions. He claimed 42 victories over the Western Front, of which 23 were Supermarine Spitfires, the remaining victories were recorded over the Eastern Front.