Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to supersede an existing airworthiness directive (AD) that applies to Model L-1011-385-1, L-1011-385-1-14, and L-1011- 385-1-15 airplanes. The existing 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. Since we issued that AD, an evaluation by the manufacturer of usage and flight data provided additional information about certain Structurally Significant Details (SSDs) where fatigue damage is likely to occur. This proposed AD would add airplanes to the applicability, change certain inspection thresholds, add three new SSDs, and remove an SSD that has been addressed by a different AD. We are proposing this AD to prevent fatigue cracking that could compromise the structural integrity of these airplanes.