Turbine Overspeed
OK guys. I was actually a jet pilot so am fairly familiar with the usefulness of pilots and that sort of thing and have certainly had to handle some fairly hairy engine incidents myself, so no sarcasm please. In some situations even lightning reactions by a pilot are no safeguard. Furthermore Kegworth was actually precipitated by pilot error! The suggestion that an automatic overspeed control would be inherently unsafe does not strike me as logical, especially when discussing the inherently unsafe aspect of a sudden disc disintegration. Modern jets have a great deal of reserve power and in the context of multijets it is obviously basic to be ready for a sudden loss of thrust at any stage of flight including TO, which would not normally lead to disaster. The fact is that whatever overspeed protection does exist in the Trent and similar engines it singularly and spectacularly failed in this instance (assuming as has been suggested the disc broke up because of a sudden and huge spin-up as a result of being de-coupled from its shaft) and could have resulted in the loss of almost 500 lives. Of course if the disc simply broke up at climb power rpm (as may have been the case) nothing would have contained it, and that would have nothing to do with overspeeding as is being postulated by some on here, which was the only issue I was addressing.