On 2/11/2012 10:10 AM, John Doe wrote:

Jeb Corliss is not just flying over terrain that is declining at
least as fast as his descent rate.

True, he is apparently deliberately diving faster that his best L/D
speed. This maneuvers him down towards the rock face while at the same
time allowing him sufficient kinetic energy to escape the declining
terrain by simply pulling up.

What appears to me to be the
very difficult part is that he flies within 10 feet of the ground.

One could argue if that's difficult or simply foolhardy. I will agree
that it's probably difficult to do it regularly without finally having
an accident.

What appears to me to be
unusually difficult about his stunt is that he has no escape
route.

Not necessarily true if he planned the stunt correctly. As long as he
maintains sufficient maneuvering energy and the terrain keeps moving
down rapidly, all he needs to do is pull up. He will simultaneously
slow down and move away from the rock face. (Trading kinetic energy for
potential energy) (See above.)