A Trent 800 engine from an Emirates Airlines Boeing 777 which suffered a catastrophic engine failure during take-off is being examined by Roll-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 a 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 shut-down on 16 September is reported to have resulted from 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 shut-down 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 TAC automatically applies up to 10¹ 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.".
Source: Flight International
