Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that currently requires inspection of the aft trunnion of the wing landing gear for cracks and corrosion, and corrective action, if necessary. This action would require new repetitive inspections for cracks or corrosion of the aft trunnion outer cylinders of the wing landing gear, follow-on actions, and repetitive overhaul of the wing landing gear. The new actions would also apply to airplanes not included in the applicability of the existing AD. The actions specified by the proposed AD are intended to find and fix cracking or corrosion of the aft trunnion of the wing landing gear, which could result in collapse of the wing landing gear and consequent reduced controllability of the airplane.