Re: Trent 800 woes [Reposted due to Enlow UCE cancel]

Date:         24 Oct 97 04:33:13 
From: (Malcolm Weir)
Organization: Little to None
References:   1 2 3 4
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On 16 Oct 97 11:59:51 , (H Andrew Chuang) caused to appear
as if it was written:

>> Essentially, the T800 failure was definitely not catastrophic!
>I don't know for a fact that it was catastrophic.  I was merely repeating
>what I had heard from two different sources that it was a catastrophic
>failure.  For the second time, Flight International reported the
>incidence as catastrophic and cited the failure was due to a high
>compressor blade fatigue.  If you have evidence that the FI report was
>inaccurate, perhaps you should say so to FI.

Here's the relevant stuff from Flight International, 24-30 Sep (Pg. 7)

EMIRATE 777 Trent engine fails during take-off

A Trent 800 engine from an Emirates Airlines Boeing 777, which suffered a
catastrophic engine failure during take-off is being examined by
Rolls-Royce.  The take-off was continued and the crew shut down the engine
and returned to Dubai, where the aircraft was landed safely.

Emirates declines to comment, beyond saying that there was an incident
involving the flight to Male in the Maldives and that the aircraft returned
to Dubai.

Unconfirmed reports from pilots in Dubai say that a failure and subsequent
engine fire occurred after V1 (take-off decision speed), but before rotation
speed.  The shutdown on 16 September is reported to have resulted in a
failure in the high-pressure compressor.

It is possible that the incident was prompted by a birdstrike, although one
source says that metal debris in the mass chip-detector is believed to have
come from the front-bearing cage. R-R says only that "...there was an
in-flight shutdown on an Emirates aircraft.  The engine is being stripped
down and we are investigating."

Preliminary indications were that the aircraft's thrust-asymmetry
compensation (TAC) function also failed to operate.  The TAX automatically
applies up to 10degress rudder when one engine produces greater than 10%
more power than the other, but only under set conditions.

When the engine failed, the Emirates' 777 engine-indication and
crew-alerting system displayed the advice "THRUST ASYM COMP".  The 777's
operations manual explains this as: "Thrust asymmetry compensation is
inoperative".  Boeing says: "It looks as if the TAC operated as it should
have.  Certain failures will not activate the TAC function, to ensure that
there is no [rudder] input in the wrong direction.".