I was told by the late Hector Cabezas, curator of the aviation museum at Munich that this patch was the real qualification badge of Interflug crew members, be it captain, first officer, engineer or navigator.. It was sewn onto the left sleeve of the uniform jacket and another smaller circular patch was sewn near it to indicate he status of the crew member. As I recall he was not very complimentary when he spoke of the metal wings worn on the jacket breast