I find this accident completely perplexing. Anyone who flies in that part of the country is surely very, very aware of the Chilterns and, in particular, Stokenchurch mast? The latter is just so famous that I cannot believe that any local pilot cannot be aware of its existence.
What do I know about the area? I was posted in to Benson as a young sprog Argosy pilot in 1962. (My last Argosy flight from Benson was in 1971).
During that time I got involved in the Benson (Chilterns) Gliding Club in my spare time and ended up as the CFI. In fact, I completed the 5-hour duration part of my Silver 'C' in an Olympia 2b sailplane (RAFGSA 232) on Chinnor ridge on 06.09.64. During those five hours I just about got to know every tree!
In those days, we used to take a winch up to a field very close to the old Chinnor cement factory chimney and launch from there. In later days we would co-operate with the gliding club at Booker (I was a good friend of their CFI [NS] and the farmer, and we would aero-tow out of one of our friendly farmer's fields with a Super Cub.
So, why am I telling you this?
I am simply trying to tell you that, as someone who is intimately familiar with the crash site, I simply cannot imagine how he ended up where he was.