Henra, you are quite correct - my original scenario, south-to-north, is incorrect.
The flight path was north to south, striking the other side of the ridge where I thought the original site was - everything fits. This knowledge and mapping actually came from a German site and it is worth re-reading this thread to see their work, which I think is correct.
Edit - here's as good a map and theory as any, posted by
mcgyvr81