Airworthiness Directives; General Electric Company CF6-50 Series Turbofan Engines

This amendment supersedes an existing airworthiness directive (AD), applicable to General Electric Company (GE) CF6-50 series turbofan engines. That AD currently requires visual inspection of the stage 2 low pressure turbine (LPT) nozzle lock assemblies, and replacement of the borescope plug with a new design plug. This amendment is prompted by a report of an uncontained engine failure on an engine that had complied with the current AD. This amendment requires additional inspections and provides interim and terminating corrective actions. The actions specified in this AD are intended to detect cracked, loose or missing stage 2 LPT nozzle lock assembly studs that could lead to failure of the locks, nozzle segment rotation, LPT case machining, and subsequent uncontained failure of the engine. The actions also provide for modifications of nozzle lock assemblies if the nozzle lock studs are found cracked, loose, or missing.