Airworthiness Directives; Boeing Model 747-400 and 747-400D Series Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 747-400 and 747-400D series airplanes. For certain airplanes, this AD requires modifying the stowage bin ladder of zone E, installing new intercostals, removing existing tie rods, and installing new tie rods. For certain other airplanes, this AD requires modifying the lateral shear beam. This AD results from a report indicating that the overhead lateral shear beam aft of main entry door number 5 reacts to certain loads from the weight of the center stowage bins of zone E and additional loads. We are issuing this AD to prevent detachment of the center stowage bins of zone E at forward load levels less than 9g during an emergency landing, which could cause injury to passengers and/or crew and could impede subsequent rapid evacuation.