An Oxford University/Rolls Study from 4/9/02 - 9/30/03 document notes that 10% or more of RR engines fail the final passing out test due to imbalance. 11 Trent 500 production engines failed pass-off testing due
to abnormal vibrations. This indicates that there was a systemic vibration problem. A higher rejection rate due to vibration is detected when the engines are overhauled at the RR appointed agents.
I have just been exposed to the rb211 on the 752, it is valuable due to it's long on wing time. We have our first pratt powered jet that get's better econemy but has to go out for overhaul in half the time. Just wondering if modern RR/Trent motors are closer to competing with N2 powered aircraft in fuel burn. The company I work for cares more about reliability than fuel cost's as we profit on our flights based on rock solid logistics and carry a high liability over most airlines for late flights.
Edit or note, ok 3 spool motors burn gas, just wondering if the time between overhaul is worth it? One down aircraft equals millions in revinue lost in a day..