Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 767-300 and -400ER series airplanes. This proposal would require replacing the tie rods for the waste tank cradle, related investigative actions, corrective actions, and special retrofit action if necessary. This action is necessary to prevent possible failure of the main deck floor stanchions and consequent collapse of the main floor during an emergency landing, which could result in passenger injury and impede passenger evacuation from the airplane. This action is intended to address the identified unsafe condition.