Bearfoil
Have you taken into account the AD amendment which lowered the amount of metal left on the Splines necessary for continued on wing? The original AD requirement was for an off wing strip if any single Spline showed wear of 2mm or more. Later the requirement was relaxed to require an average only of not more than 2mm for all the Splines taken as an aggregate.
The way I would read this is that, through the inspections and measurement process of the original AD, it was determined that the wear of the splines was somewhat consistent spline to spline rather than being a skewed situation where some wore much greater than others resulting in the amended AD.
To my knowledge the Splines AD's are still in force. If this is so, the manufacturer may be performing retro fits of the internals that caused the Splines to wear so quickly, and replacing "Oil Pipes" at the same time. I am unfamiliar of the Regulatory process that allows an operator/manufacturer to ignore prior and "unrelated" AD's simply because they are honoring new ones?? Can you help with this??
I would believe the AD for spline inspection is a continued requirement until such time a corrective measure is proposed by Rolls Royce and approved by EASA. Then the current spline AD would be replaced with a new one (or revised one) that would instruct the operators to incorporate the change/improvement by a certain time or specific engine cycle completion after the last spline wear inspection. The two AD's are completely separate from one another and accomplishing one (check for oil leaks) does not relieve responsibility to perform the other (spline wear inspection and measurement). I am sure this doesn't make any of the airline operators happy at the moment as it is disruptive to scheduling, etc.