Action
Final rule.
Summary
We are superseding an existing airworthiness directive (AD) for all Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model L-1011-385-1, L-1011-385-1-14, and L-1011-385-1-15 airplanes. That AD currently requires implementation of a Supplemental Inspection Document (SID) program of structural inspections to detect fatigue cracking, and repair if necessary, to ensure continued airworthiness of these airplanes as they approach the manufacturer's original fatigue design life goal. This new AD adds Model L-1011-385-3 airplanes to the applicability, changes certain inspection thresholds, adds three new structurally significant details (SSDs), and removes an SSD that has been addressed by a different AD. This AD was prompted by an evaluation by the manufacturer of usage and flight data that provided additional information about certain SSDs where fatigue damage is likely to occur. We are issuing this AD to prevent fatigue cracking that could compromise the structural integrity of these airplanes.