Airworthiness Directives; General Electric Company (GE) CF6-50 Turbofan Engines

This amendment adopts a new airworthiness directive (AD) that is applicable to General Electric Company (GE) CF6-50 turbofan engines. This amendment requires removal of old high pressure compressor (HPC) air ducts and mating hardware and replacement with newly designed air ducts and reworked mating hardware. This amendment also requires the repetitive inspection of certain reworked mating hardware. This amendment is prompted by reports of an uncontained low pressure turbine (LPT) disk failure that resulted from an air duct failure that caused a fan mid shaft (FMS) separation. The actions specified by this AD are intended to prevent HPC air duct failures that could result in FMS failures, that in turn could result in rejected takeoffs or uncontained LPT events, and to prevent HPC rear shaft failures that could result in uncontained engine failures.