Airworthiness Directives; General Electric Company Turbofan Engines

The FAA is adopting a new airworthiness directive (AD) for certain General Electric Company (GE) CF34-8C and CF34-8E model turbofan engines. This AD was prompted by an "Engine Degraded" message received in-flight from the Engine Indicating and Crew Alerting System (EICAS), and a subsequent investigation by the manufacturer that revealed corrosion of the variable geometry (VG) system actuator, which can cause the full authority digital engine control (FADEC) software to command and lock the engine at idle until it is restarted. This AD requires performing a rotational torque check on the actuating linkage assembly and, depending on the results of the rotational torque check, replacement of the compressor inlet guide vane (IGV) outer shroud bushing and vane spindle bushing with parts eligible for installation. This AD also requires reporting the results of the rotational torque check to GE. The FAA is issuing this AD to address the unsafe condition on these products.