Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-10-10, -30 and -40 series airplanes, and KC-10 (military) series airplanes. This proposal would require repetitive high frequency eddy current (HFEC) inspections to detect cracks in the number 4 banjo fitting on the rear spar of the vertical stabilizer, and repair and modification of the vertical stabilizer, if necessary. It also would require the installation of a modification as terminating action for the repetitive inspections. This proposal is prompted by reports of failed attach bolts and cracking found in the area of the number 4 banjo fitting, which were caused by higher than normal operating stresses. The actions specified by the proposed AD are intended to prevent reduction in the structural integrity of this fitting due to failed bolts and cracking. This condition, if not corrected, could ultimately lead to reduced controllability of the airplane during flight and ground operations.