Turbine D
On the money. A good argument that the 900 is not in the same family as the prior iterations of TRENT would be that the destructive issue at the heart of the dilemma does not affect the others. In using this, RR suggests that the 900 is in fact substantially different from the others.
The problem is distilled as usual into likely courses of action. The question is this..... Will for once the authorities demand a revocation, or will they succumb to pressure to keep the troubled engine in service, although it has obvious service life issues? These issues cause an accelerated loss of dependability, such that mere inspections beg the question!!
Have you searched for the specs on the "C" Modification? Given the reported limits on service, the obvious conclusion is that this powerplant is a "work in Progress". Odd that no one will address the issue, but merely defend the indefensible. I only have the "B1" manual, so my limits are strict. I do know from sources that virtually no oil issues were found in the eighteen months prior to the Burst. I also know from sources what the precise issue is. If so, the fix has some pretty lofty obstacles to a simple cure.
DERG
The seventy cycle limit was required by EASA, not "reported" by RR. No doubt there was a consult, there always is. The consult in August produced the relaxed (lax) inspection cycle amendment in September to allow Spline Wear per se to be "averaged" or normed, using each pair as a contributor instead of the "worst worn" disqualification. It was this very relaxation that allowed the Burst to happen, clearly the wear had proceeded such that certain "pairs" were not even functioning.
Last edited by bearfoil; 8th Feb 2011 at 00:37.