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Action

Final rule.

Summary

We are adopting a new airworthiness directive (AD) for certain Rolls-Royce Corporation (RRC) 250-C20, -C20B, and -C20R/2 turboshaft engines. This AD was prompted by seven cases reported of released turbine blades and shrouds, which led to loss of power and engine in- flight shutdowns (IFSDs). This AD requires a one-time visual inspection and fluorescent penetrant inspection (FPI) on certain 3rd and 4th stage turbine wheels for cracks in the turbine blades. We are issuing this AD to prevent failure of 3rd or 4th stage turbine wheel blades which could cause engine failure and damage to the airplane.

Document

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