Dave_Jackson,
Thanks for the link to the accident report.
Yes, the report shows a slightly lower number of rotorcraft accidents attributable to engine related systems versus gearbox related systems. But one might argue that does not mean engine systems are more reliable or have a lower MTBF. In fact, one might argue that the only reason engine failures have not produced more accidents is due to the functional fault tolerance provided by a single main gearbox with multiple engine inputs.