Big John wrote in
:



The B-47 had what was called the "coffen corner". At high altitude the
airspeed was just above the stall and if you increased your airspeed
you were into Mach. This required very close attention by B-47
drivers.



Yeah, it's petty much the same with any transonic aircraft. Technically,
though, what you had at the low end wasn't a stall, though it's commonly
referred to as such. The end result was the same (plummeting to earth) but
the biggest difference was that it happened well above indicated stall
speed and well below crit Alpha.
But even the FAA call it a stall in their advisory material.

http://rgl.faa.gov/Regulatory_and_Gu...Circular.nsf/0
/e04e9b9732ba93fd86256caa005ca97e/$FILE/AC61-107A.pdf

You probably flew looser margins than we do, in fact. I've flown with about
ten knots either direction to buffet, but it's a non-event with us in
coffin corner because of the more sophisticated autopilots and
autothrottles.

In the U2 they flew with a +/- 2 knot margin! The autopiot did th ework and
they let the altitude do what it wanted in deference to speedkeeping.


Bertie