There are two deaths cards available on fold3 (
https://www.fold3.com/image/699418895 and
https://www.fold3.com/image/692292291) for Fw Franz Braun born on 22 July 1922 who died on 16 April 1943 (at 1700 hrs) in an universitary hospital in München, Germany.
Both cards agree on the above and say he was a member of Flugzeugleitstelle Luftflotte 2 (a flight test unit AFAIK). Rank is given as Flieger-Gefreiter in first card and Gefreiter in second.
First card gives no reason for death but second says he died from meningitis (with a word just before that I can't decypher).
My comments (only my own, humble opinion):
1) this guy probably dies from disease rather than from wounds, whatever the sterbebild said (but who knows what the family was told at the time?)
2) the rank of Flieger is the lowest rank in the Luftwaffe, and does not imply that the man wearing it was actually an air crew. By the way in 1943 such a low rank would be very unusual for a pilot, and probably the result of a martial court. He could well be a ground crew.
3) Flugzeugleitstelle were normally rear area units and given the situation in Tunis (which was never far from Allied lines during the whole campaign, and certainly heavily wounded during the period, especially in April 1943), I doubt Flugzeugleitstelle Luftflotte 2 would have been based here, but I have no proof. Still this man could have been sent there for some mission, but it is more probable he fell ill somewhere in Italy or Sicily before being sent to an hospital in Germany where he died.