Given the nature of the defect that apparently initated the crack, why is the inspection limited to Turbo Mallards? Why not R-1340 powered ones?
(I could even ask - why limited to Mallards?)
The AD is temporary in nature (data gathering) and only a start. As the data becomes available expect more updates.
A little bit like the B747 pylon issue. We asked the same questions then. Why stop at the B747? With time the answer became clearer as more than a few folks offered up data beyond the B747 giving us back a warm feeling.