Re: 42,000 feet

Date:         25 Mar 97 03:38:10 
From:         katie@physics12.Berkeley.EDU (Katie Schwarz)
Organization: UC Berkeley
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Karl Swartz <kls@ohare.Chicago.COM> wrote:
>>I thought I'd seen a discussion (in this newsgroup?) that concluded that
>>the reason commercial airliners don't go above 41,000 feet is that it
>>wouldn't be economic to make the fuselage thick enough to handle the
>>pressurization.
>
>Obviously not, since the 767 is certified to 43,000 feet (according to
>http://www.boeing.com/) and Concorde routinely flies above 60,000 feet.

Concorde is a different story, of course -- I meant subsonic commercial
airliners.

I got an e-mail from someone suggesting that the engines lose a lot of
fuel-efficiency above 40,000 feet because "your turbofan engine turns into
a turbojet engine." Anyone have any comments on how important this might
be, compared to the issue of weight?

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Katie Schwarz                  <*>               katie@physics.berkeley.edu