Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Boeing Model 707 and 720 series airplanes. This proposal would require an inspection of the main landing gear (MLG) lock support fitting and the wing fillet flap support link for damage, and corrective action, if necessary; and replacement of the bolts and bushings at the joint between the MLG lock support fitting and the wing fillet flap support link. This action is necessary to prevent stress corrosion cracking of the bolts and wearing of the joint between the lock support fitting and the support link, which could lead to failure of the joint and could cause the collapse of the MLG. This action is intended to address the identified unsafe condition.