On Apr 12, 8:26*am, Jack wrote:
Andy wrote:

* You'll need to define how height and altitude

are independent.

Height = AGL
Altitude = above MSL

Jack

My understanding is NO. Here's an example:

On the CRJ at 10,000 feet best L/D is 170 kias......then at the same
weight and ISA deviation and flap setting, stall speed at 41,000 feet
is 173. So if you pitched for best L/D for 10,000 at an altiude of
41,000 feet you would stall the airplane. I know this because I have
studied in great detail flight 3701. Those pilots just a few years
ago, stalled the crj at 41,000 feet at 173 knots. Then they glided
the 50 seat passenger jet into a neighborhood in the middle of the
night. The plane exploded and both pilots died. No passengers aboard
the flight. It was a reposition. Very sad day.

KIAS stall speed changes with altitude....so does L/D KIAS.