Summary
This document revises an earlier proposed airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-10 series airplanes, and KC-10A (military) airplanes, that would have required high frequency eddy current inspection(s) to detect cracks in the secondary pivot support of the horizontal stabilizer, and various follow-on actions, if necessary. That proposal was prompted by reports of crack development in the secondary pivot support of the horizontal stabilizer due to fatigue. This action revises the proposed rule by adding repetitive visual inspections. The actions specified by this proposed AD are intended to prevent such fatigue cracking, which could result in reduced structural integrity of the horizontal stabilizer and, subsequently, lead to reduced controllability of the airplane.