Re: Passenger cabin pressurization

Date:         10 Sep 97 19:38:45 
From: (Gerard Foley)
Organization: The Greater Columbus FreeNet
References:   1
Followups:    1 2
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jf mezei ("[non-spam]jfmezei" wrote:

: I have seen mentioned often that modern airliners maintain a cabin
: pressure of 8000feet when flying at cruise altitude of 30-40k feet.

: Is this an urban myth or actual precise figure that applies to all
: airliners ?


   I used to carry a pocket altimeter with me on airplanes (lately I
forget to take it).  Different aircraft behaved in different ways,
but I never had one that got down as low as 8000 feet equivalent
pressure.  It was apparent that some regulated on cabin pressure,
and some had a growing differential between external and internal
pressure as the plane climbed.  My recollection is that 727's
had a gradual decrease in cabin pressure, while DC9's kept
the cabin pressure high until reaching pretty high altitude.

  There was usually a little bump upward in cabin pressure when
the doors were closed.