Mish

Do you have enough bleed air with throttles at idle?

Thrust curve is not linear with throttle position so some rpm above
idle might be required in some birds???

Change in time down to 18K or so would not be much different. I used a
figure of 18K as a target alt to get on the safe side in a emergency
descent.

USAF set 34K (cockpit altitude) as the point to go to pressure
breathing. Easy to suck in and fill lungs and hard to breath out (open
exhaust valve). This assisted the lungs to get enough oxy. Took a
while to accustom to blowing out with each breath against valve but
soon became routine.

Big John
Pilot ROCAF


On Mon, 05 Jan 2004 18:38:52 GMT, "Gary Mishler"
wrote:


"Scott M. Kozel" wrote in message
...
How could an SST like the Concorde get from cruising altitude down to
10,000 feet in 3-5 minutes?

Easy, it's called an Emergency Descent. Power to idle, spoilers/speedbrakes
deployed, maybe gear extended (depends on aircraft), then dive at redline
speed. The airplane I fly (Lear 60) it takes an initial deck angle of ~ 20
degrees nose down to obtain redline, then ~ 10-12 degrees to hold it there.

We practice it every time we have a simulator check. Never takes more than
3 mins to get from FL450 to 10,000 ft.

Mish