 nir 3432 cl170 bearing failure leading to fire cl170 turbostar bearing failure risk controls are being actively managed a bearing modification programme is progressing at c4 overhaul and turbostar operators are monitoring bearing condition via sensors and riding inspectors porterbrook is continuing to liaise with tocs on monitoring arrangementselectros	tar bearing monitoring arrangements are under review with gtr porterbrook is supporting gtr with the trial of new monitoring sensors 