Re: ETOPS Question

Date:         29 Nov 97 03:24:29 
From:         John van Veen <jvanVeen@worldnet.att.net>
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Steve Lacker wrote:
> David Lesher wrote:
> > faurecm@halcyon.com (C. Marin Faure) writes:

> > >All ETOPS twins must be able to immediately start their APUs at cruising
> > >altitude even after hours of cold-soaking.
> >
> > Could you not just heat the APU's normally, given you will be
> > starting it ASAP if you lose an engine anyhow?
>
> "Heating the APU normally" is descending into warm air and allowing it
> to warm up due to the ambient temperature :-)

When the combustion temperature, maybe 1100 degrees, of the fuel burning
in the APU is considered, there isn't much difference between -45
degrees and +90 degrees.  Both temperatures are very cold relative to
how warm it will get.  Maybe someone who knows more about this has a
comment.

John