Hi Divinehover
you don't want to ever see one of these. This is the same failure mode as the Sioux City DC10 engine failure (see
http://www.airdisaster.com/special/special-ua232.shtml). Imagine thas fan disc in the engine is about 300lb in weight, turning at up to about 2,000rpm and it decides it doesn't want to be round anymore, rather it would like to disintegrate into a number of smaller not so round pieces and see what life is like outside the confines of the engine. It would probably find it's way up into the pylon/wing and make a not so pretty mess of the fuel system. Hence the FCOM note.
Happy flying!
