Hi @ all, the following were not all aces, though the all were members of the Fliegertruppe:
don't forget the Boelcke-Brothers Oswald and Wilhelm who served in 1914/15 both (as one crew) in the FFA 13.
I never found him... but Franz Immelmann, Max' little brother, was an aviator, too (as he writes in the Immelmann-Book "Der Adler von Lille".
Will Gabriel's twin-brother was an aviator; the Bolle Brothers in
Jasta Boelcke...
...I am not sure, but I think: there were lots of brothers in the German Air Force
One last one: Erwin (+27.11.1917) and Max Boehme (+21.04.1918 )