Airworthiness Directives; Rolls-Royce Corporation Turboshaft Engines

We are adopting a new airworthiness directive (AD) for certain Rolls-Royce Corporation (RRC) model 250-C turboshaft engines. This AD was prompted by several reports of engine power loss, one of which resulted in a fatal helicopter accident. This AD requires removal of the power turbine governor (PTG) bearing assembly, part number (P/N) 2544198, and its replacement with a bearing assembly eligible for installation. We are issuing this AD to address the unsafe condition on these products.