Airworthiness Directives; Allison Engine Company AE 3007A and AE 3007C Series Turbofan Engines

This amendment adopts a new airworthiness directive (AD) that is applicable to Allison Engine Company AE 3007A and AE 3007C series turbofan engines. This action supersedes priority letter AD 98-02-09, that currently requires certain checks of the center sump magnetic chip collector plug for paste. Engines found with paste are required to be removed from service. This action references revisions of the applicable Alert Service Bulletins (ASB) providing clarifications of check procedures. This amendment is prompted by a change in the part number applicability, a change in the check interval, and the publication of these revised ASBs. The actions specified by this AD are intended to prevent No. 4 bearing failure due to excessive bearing wear, which can result in an inflight engine shutdown.