Re: Oxygen

Date:         24 May 99 01:52:24 
From:         rdd@netcom.nospam.com
Organization: Netcom Online Communications Services (408-241-9760 login: guest)
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In article <airliners.1999.519@ohare.Chicago.COM> Don Stauffer <stauffer@gte.net> writes:
>The cabins are pressurized.  An air compressor compresses the air until it
>has the same pressure as about 8000 ft altitude.

The cabin gets pressurized by the fact that air enters the cabin faster
than air leaves the cabin.

Air entering the cabin is a direct function of altitude and engine
power.  The higher you get, the less air you get from the engines.

The actual cabin altitude is controlled by one and sometimes two outflow
valves.  These are controlled by a pressurization controller, which is
a analog or digital computer that is designed to keep the cabin at either
a selected or programmed altitude.

There is much more on the subject in the sci.aero.airliners archives.

There is no compressor sitting around measuring and compressing the
cabin air.

R.
--
Robert Dorsett                         Moderator, sci.aeronautics.simulation
rdd@netcom.com                         aero-simulation@cactus.org

           "Bother," said Pooh when his engine quit on take-off.