One of the most hidden source - for all WW1-aviation questions - is the Krankenbuchlager (KBL) Berlin. Whereas a lot of personal documents of former aviation-officers can be found in the Bundesarchiv/Militärarchiv, KBL does only provide information, if one can present a power of the respective family member. That's really a hard job! >
I'm sure that a lot of Stofl/Kofl are known among the researches - excluding those of the Eastern front units!
Mosen