Airworthiness Directives; Boeing Model 757-200 Series Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 757-200 series airplanes, that currently requires inspections to detect cracking on the free edge of the tang, if necessary, and of the fastener holes in the lower spar chord; and various follow-on actions. That AD also provides for an optional terminating action for the repetitive inspections. This amendment adds inspections to detect additional cracking of the fastener holes in the lower spar chord. This amendment also adds an optional terminating modification. This amendment is prompted by the issuance of new service information. The actions specified by this AD are intended to detect and correct fatigue cracking in the lower spar chord, which could result in reduced structural integrity of the engine strut.