I may be confused but isn't roscoe's link to a news report with a
headline stating 'Super Puma crash was gearbox failure' - the actual AIBN report doesn't say anything of the sort, it just says:
Recent metallurgical findings have revealed features strongly consistent with fatigue in the outer race of a second stage planet gear in the epicyclic module of the MGB. It cannot be ruled out that this signifies a possible safety issue that can affect other MGBs of the same type. The nature of the catastrophic failure of the LN-OJF main rotor system indicates that the current means to detect a failure in advance are not effective.
- which is what we already knew?
TeeS