@Peter H, others
I no more remember the tittle of the books.
They are written in German, the tittle could be something like General aerodynamic works (Generale aerodynamischen Studien ???)
As the author is now well known some German University have probably the original books recovered with dust.Perhaps the name of Prandtl was only inside. The books were green middle sized, , perhaps 100-200 pages for each book.
I already searched on the web some of the curves, but without success. I did not tried to find books again. Mine were in the library from my ornthologist oncle and I was surprised to find them after he died. Nobody in the family was interested,they seemed not modern science ! For me it was a treasure to teach my new pilots.
Very pedagogic works for today pilots.. and for aviation administration, BEA, etc. who seem to have very raw and low documentation about stall (AF447 final report !!)
Decade after decade the knowledge taught in the books was poorer, often false in french litterature, included to teach airline pilots and ENAC APTL preparation... And finaly really ignorant airline pilots diving in the Ocean.
