Thank you both for your reply.
Why not a loss during a transfer.
I found a 171714 from the JG6 lost in late August 1944, it seems to be very close to this 171721...
I tried to colorize the picture for trying.
What about the missing canopy ???
The fields near Saint Fergeux (close to Herpy) are sometime grown with beets. Is it possible that a plane which should land in Herpy didn't succeed in during its transfer from Germany late August ?