Re: B747 technical questions

Date:         11 Jul 97 02:09:24 
From:         rdd@netcom.com (Robert Dorsett)
Organization: Netcom Online Communications Services (408-241-9760 login: guest)
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In article <airliners.1997.19@ohare.Chicago.COM> lowwol@christine.pacific.net.sg writes:
>1) For the 5th engine which can be installed on the pod under the wings,
>can it be used as part of the aircraft's engine thereby making the
>aircraft run on five engines?

No.  It's just a hard point to hang something.  There is none of the
necessary plumbing to make it do anything.

>2) What is the best EPR number to be attained?  Is it the smaller the
>number the better or the greater the better?  Since EPR=turbine
>discharge pressure: compressor inlet pressure.  And why?

EPR is a direct indication of the thrust being produced by the engine.
So higher = better.  An EPR of 1.0 is an engine not doing much of anything.
EPR values will vary by engine type and nacelle design.  So a 727 that
might have a 2.0 takeoff EPR isn't necessarily more powerful than a 747
with a 1.3 takeoff EPR.

>3) What is in the inside of an aircraft tyre?  I mean is it
>filled/pumped up with air like that of car tyres or is it built as a
>solid whole piece??

Air. Or, if you wish, do a search on the archives (www.chicago.com/airliners)
for "nitrogen". :-)

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

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