Bolty McBolt
If you read back, you will find bearing seizure is addressed. Also Stall/Surge. In my opinion, whether the HP/IP Roller bearings failed (I think they did) or not, the problem is at the Rigid coupling, the IP/HP thrust (Ball Bearing) locale. This "Module" is insufficient in service to withstand not only great Thrust, but its own idiosyncracies that disqualify it as TRENT anyway. The weaknesses are not my imagination, they are documented and described by the regulator, and stingily by the Actions of the Manufacturer in attempting to design a new engine whilst it (the 'current' iteration de jour) labors on wing in Public Carriage. The "C" mod is not capable of solving the teething problems to satisfy the parameters of the original certificate. It is a Stop Gap, an attempt to keep the engine viable. The alternative is to admit the engine is not ready for service, and face economic failure, and potential criminal prosecution. Will we see this circuitous fraud in the light of day?? Perhaps. Are you a betting man??
Will the "C" last to the expected service life? I think not, another newer module will replace it, and on, and on. What do you think?