Re: Details on recent PW-4xxx engine problems?

From:         hac@b747.res.utc.com
Organization: United Technologies Research Center
Date:         22 Jul 94 12:44:04 
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> >In assorted recent postings (largely on rec.travel*) I noted claims
> >of recent problems with PW-4xxx engines on B-767 and MD-11 aircraft.
> 
> While they didn't lead to a crash, the problems with the PW4460 on the
> MD-11 appear to be somewhat more serious.  At least one airline (China
> Air?) temporarily grounded their MD-11 fleet after suffering a number
> of compressor stalls.  (Andrew, can you provide further detail?)

I don't have much detail.  Taiwan's China Airlines and Swissair had once
grounded their MD-11 fleet.  I'm a little bit more familiar with CAL's
saga.  If memory serves (all the following numbers are ballpark figures),
CAL introduced their first MD-11 in late 92.  In the first six months of
operation, the first two aircraft accumulated 11 delays/cancellations due
to mechanical problems: nine were engine related, and seven were due to
compressor stall.  The media and the public in Taiwan forced the airline to
ground the fleet.  It took at least two weeks before P&W came up with a fix.
After the fix, I am aware of at least another compressor stall on one of the
first two aircraft.  However, I have not heard any serious engine problem
with the rest of CAL's MD-11 fleet.  A few months later, Swissair was
experiencing engine surge problems and grounded their fleet.  P&W seemed to
have solved Swissair's problem in about a week.  As reported in AvWeek, P&W
claimed CAL's and Swissair's problems were unrelated.  Someone has posted
about similar problems with the B767s, but I don't really have any info on
that.  To the best of my knowledge, other than CAL's initial MD11
experience, the problem is not that wide-spread. Otherwise, the public would
have heard a lot more about it.

H Andrew Chuang