Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-10 series airplanes and KC-10 (military) airplanes. This proposal would require repetitive inspections to detect fatigue cracking of the rear spar cap of the horizontal stabilizer; and repair, if necessary. The proposed AD also would require a preventive modification of the rear spar cap of the horizontal stabilizer, which would constitute terminating action for the repetitive inspections. This proposal is prompted by reports of fatigue cracking of the rear spar cap of the horizontal stabilizer. The actions specified by the proposed AD are intended to prevent fatigue cracking of the rear spar cap of the horizontal stabilizer, which could result in reduced structural integrity of the horizontal stabilizer, and consequent reduced controllability of the airplane.