"George Patterson" wrote

The flight started on a ridge of the Appalachians. The pilot followed the
ridges
down to Tennessee, staying on the western side about 50' AGL. That way he
stayed
in a constant updraft. The article I read said the turbulence was brutal.

I suspected that. I bet he was higher than 400 feet, at times, and well
above 50 almost all the time. Steepness in places at that altitude would
have put a wing into a mountain!
--
Jim in NC