Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 737-200, -200C, -300, and -500 series airplanes. This proposal would require replacement of the bolt and self-locking nut on the primary support pin of the main landing gear (MLG) support beam with a new bolt, castellated nut, washer, and cotter pin. This action is necessary to prevent the loosening and loss of the support pin retaining bolt on the MLG, which could result in the loosening and movement of the support pin and consequent cracked support fittings and collapse of the MLG. This action is intended to address the identified unsafe condition.