Airworthiness Directives; General Electric Company CF6-80A3 Series Turbofan Engines

This amendment supersedes an existing airworthiness directive (AD), applicable to General Electric Company (GE) CF6-80A3 series turbofan engines, that currently requires initial and repetitive on- wing borescope inspections of the left hand aft engine mount link assembly for cracks, bearing migration, and bearing race rotation, and if necessary, replacement with serviceable parts. This AD requires initial and repetitive visual inspections of both left hand and right hand aft engine mount link assemblies for separations, cracks, and bearing race migration. Cracked or separated parts will have to be replaced prior to further flight. If spherical bearing race migration is discovered, a borescope inspection for cracks is also required. If no cracks are discovered by the additional borescope inspection, assemblies would have a 75-cycle grace period for remaining in service before replacement. Finally, installation of improved aft engine mount link assemblies will constitute terminating action to the inspections of this AD. This amendment is prompted by a recent analysis of internal bearing friction and bearing migration and inspections, which revealed migrated spherical bearing races on two CF6-80A3 series and ten CF6- 80C2 series aft engine mount links. The actions specified by this AD are intended to prevent aft engine mount link failure, which can result in adverse redistribution of the aft engine mount loads and possible aft engine mount system failure.