Britace,
the term "Flieger" is not allways meaning pilot. It is the rank of a soldier in the Fliegertruppe. So this man could also be a common soldier in any ground service function. Even worse the man´s name is Müller - the worst thing which can happen to a researcher of German soldiers. Albert Müller makes it not much better - you can already find 6 guys with this name in the list of dead German aviators in COTGAS. I wonder how many surviving Albert Müller´s are known?
Could you translate the text?
This AM had just finished a leave to Herne/Westphalia - his hometown??
Altenburg was a very long time under Saxon rulers but was not part of the kingdom of Saxony in WWI. Today it is part of Thuringia but we Saxons feel it should be part of Saxony.