Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 777-200 series airplanes. This proposal would require replacement of certain existing bushings of the aft trunnion of the outer cylinder of the main landing gear (MLG) with new bushings, and replacement of grease in an undercut on the aft trunnion, if necessary. This action is necessary to prevent stress corrosion cracking and consequent fracture of the aft trunnion of the outer cylinder of the MLG, which could result in collapse of the MLG. This action is intended to address the identified unsafe condition.