WojtekSz
IMO Rolls had identified the problem prior to the AD. They negotiated a schedule of inspections meant to monitor the wear on the Splines at Abutment Face. Clearly the AD took into account the actual cause of the problem, for goodness' sake, they approved the Fix!! The "C" modification was to have mooted all concern, for the Engines under the AD's demands were to have been pulled from service so the Power was "Exonerated". The Explosive Burst put everything into limbo. It became clear Rolls was furnishing the new engine to Airbus for facilitation of delivery of new aircraft, whilst the 972 was on wing, subjecting each flight to hazards at clearly, (Demonstrably) unacceptable levels.
How could RR not have known the source of the trouble and then claimed the "C" mod was sufficient?? Magic?? Guesswork?? Chicken Guts??
The relaxation of the inspection regimen is on the EASA's shoulders solely. They put their faith in RR and their bluff, as RR cynically advantaged the gullibility of the regulator, and their Prime client for the TRENT 972. (QANTAS).
It turns out the C mod is under the gun, and QANTAS is taking their sweet time approving LAX SYD flights at max thrust (max TOW) Where does this put the TRENT 900?? Do-Overs?? How about, 'once burned, twice shy'.......