Re: 42,000 feet

Date:         21 Mar 97 02:43:25 
From: (Terry Schell)
Organization: University of Illinois at Urbana
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Malcolm Weir <> writes:

>Andrew Muir wrote:
>>  Now, how fast can you dive a concorde?

>Well, it's the one airliner that need not worry about going supersonic
>in a dive...  8-)

Actually, if you assume that the Concorde has a L/D ratio of 8/1 in
cruise and cruises at 1200 mph (what is mach 2.04 at fl60?)
then it should decend at approximately 150mph.  That gives
you a decent rate of about 13200 fpm. Less than 4 min to get back to
breathable atmosphere.

If you were willing to decend at Vne... you could drop like a stone.
Does anyone know what Vne on the concorde is?  If it is mach 3 and the
L/D at that speed is probably around <guesstimate> 5/1, you could get
down in 113 seconds.

Even adding a bit to account for the time it takes to enter the
decent, this plane can get to breathable air fast enough to be safe
with full-depresurization at fl60.  In fact, much faster than normal
jets as fl40.

If anyone has more precise numbers... post 'em.