Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all Lockheed Model L-1011- 385 series airplanes, that currently requires inspections to detect cracking and other discrepancies of certain web-to-cap fasteners of the rear spar between inner wing stations (IWS) 310 and 343, and of the web area around those fasteners; and various follow-on actions. That AD also provides for an optional modification, which, if accomplished, would defer the initiation of the inspections for a certain period of time. This action would require accomplishment of the previously optional modification. This proposal is prompted by an FAA determination that the optional terminating modification specified in the existing AD must be accomplished within a specified period of time to ensure an acceptable level of safety of the affected fleet. The actions specified by the proposed AD are intended to prevent fatigue cracking in the web of the rear spar of the wing, which could result in failure of the rear spar of the wing and consequent fuel spillage.