Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-11 series airplanes and Model DC-10-30, DC-10-40, and KC-10A (military) airplanes. For Model MD-11 series airplanes, this proposal would require an inspection to determine the serial number of the forward trunnion bolts on the main landing gear (MLG), and rework or replacement of the bolts, if necessary. For Model DC-10-30, DC-10-40, and KC-10A (military) airplanes, this proposal would require an inspection for evidence of missing chrome and for corrosion on the chrome surfaces, or verification that the forward trunnion bolts have been chrome plated in a specific manner; and rework or replacement of the bolts, if necessary. This proposal is prompted by reports of chrome flaking on the bearing surface of the trunnion bolts due to improper cleaning of the base material prior to chrome plating. The actions specified by the proposed AD are intended to prevent premature failure of the trunnion bolts and subsequent collapse of the MLG as a result of severe corrosion on the bearing surface and in the mechanical fuse due to chrome flaking.