Date: 01 Oct 97 19:57:48
From: malc@mci2000.com (Malcolm Weir)
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On 28 Sep 97 00:53:39 , Chuanga@cris.com (H Andrew Chuang) caused to appear
as if it was written:
>An earlier rumor of a catastrophic failure of a Rolls-Royce Trent 800
>engine during an Emirates' B777 take-off was confirmed by this week's
>Flight International (9/24-9/30).
[ Snip ]
> However, the Trent 800 seems to have experienced many
>more woes than either the PW4000 or GE90. (Were I a Delta executive, I
>certainly would seriously reconsider the B777 engine selection before
>excercising Delta's B777 options.)
Flight Internation 10 - 16 September states:
"Pratt & Whitney says that an upgrade effort to counter reliability problems
on more than 1,600 PW4000 engines is showing results, with a 'dramatic
reduction' to in-flight shutdown rates.
The upgrade effort, known as the Number 1 reliability programme, involves
around 100 service bulletins. More than 70 PW4000 customer airlines have
incorporated around 80% of the improvements into their engines, says P&W.
It adds that the 12-month rolling average in-flight shutdown rate for the
fleet has dropped from 0.014% in January 1997 to 0.008% in August as a
results".
Specific to the 777, "P&W confirms that it is replacing the low-pressure
turbine (LPT) stage-five vanes from PW4077 engines in service on Boeing 777.
'We saw this in validation tests for ETOPS, and we saw some areas in the LPT
vane that needed improvement."
So perhaps Delta's selection of RR is as good as P&W? Particularly since
the Trent's problems seem to be self-identifying (i.e. oil temperature
climbs through the roof), while some of the PW4000 problems involved
modifications to the leading edges of the fans due to cracking after foreign
object impacts...
Malc.
