Re: Cabin pressure profile?

From:         hoyme@src.honeywell.com (Ken Hoyme)
Organization: Honeywell Systems & Research Center, Mpls. MN, USA.
Date:         23 Sep 93 00:11:30 PDT
References:   1
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In article <airliners.1993.598@ohare.Chicago.COM> ctillier@phoenix.princeton.edu (Clemens Emmanuel Tillier) writes:

> This is a somewhat vague question, but here goes: 

Well, I will give you a sonewhat vague answer....  :-)

> How does the cabin pressure in a 'typical' airliner vary with
> altitude? Of course it decreases, but how? Is there a proportional
> decrease as you go up or does it follow atmospheric pressure to a
> certain altitude and stay at this final pressure as you go higher?

It is proportional, in my experience.  I have jumped several airplanes
and the most clear in this regard was the A320.  They have an
environmental systems graphic on one of the CRTs during ascent that
shows the internal cabin 'altitude' and the relative internal
ascent/descent rate.  During climb the internal rate was equivalent to
500 feet per minute and at cruise the internal 'altitude' was typically
7500' above sea level.

> Even more basic: what is a 'typical' cabin pressure at say 35,000
> feet, and to what real altitude does it correspond?

Answered above.

Ken

Ken Hoyme                    Honeywell Technology Center
(612)951-7354                3660 Technology Dr., Minneapolis, MN 55418
Internet: hoyme@src.honeywell.com