Re: ETOPS Question

Date:         21 Nov 97 01:59:52 
From:         "Michael F. Lechnar" <michael.f.lechnar@boeing.com>
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Karl Swartz wrote:
{Snip-Snip)
> I'm pretty sure none of the Boeing airliners have APUs certified for
> re-start once cruising altitude has been reached, primarily because
> of problems getting it lit after an extended cold-soak.  That doesn't
> imply that it *can't* be started in the air, and perhaps at lower
> altitudes it might work if you had to try it.

Nope,

In order to do ETOPS, you must have a working APU.  The Ops manuals for
the 767s that I just took a quick look at all say that the APU can be
started in the air, and indeed must in some circumsances.  The 757 and
777 APUs can as well.

You are right about the 747-400.  The APU is not approved for air
starts, but may be kept running to 20,000 ft.  The APU on the classic
747 may or may not be started in the air.  It actually depends on the
decal pasted to the engineer's panel.

Mike Lechnar
Aircraft Performance Engineer
"If I was speaking for Boeing, I wouldn't be doing it here."