Luftwaffe ”schoolbook/notebook” WW2

[Chrysler73]

Hi,
Hope everything is fine with you!
I am somewhat curious about three "notebooks" that I found in a fleamarket in Normandy last year. They belonged to young (at least according to the photo...) Obergefreiter in the Luftwaffe named Kühlborn and are dated spring 1944. They are filled with extremely well written aviation lecturenotes in german on technical and navigational subjects, and also contains nice illustrations, charts and diagrams. Seems to be written in some kind of radiooperators logbook?
This is not my area of expertise at all, but I am now courious if these type of documents are common? Any value? Any tips on where to do research on the fate of our young pilot/student/aviator...?

Best regards and thanks in advance

 

[MiTasol]

great find but unfortunately I cant help you. I am sure others will

 

[fubar57]

He must have had a promotion since his photo was taken as it shows him as a Private. Interesting find