Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 767-200 and - 300 series airplanes. This proposal would require replacement of the existing potable water fill line tube with a new hose. This action is necessary to prevent fracture of a clamshell coupling on the potable water fill line, which could cause water to flow into the aft cargo compartment. A large amount of water in the cargo compartment could cause large shifts in the airplane's center of gravity, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.