AD FAA-2014-0780

We are adopting a new airworthiness directive (AD) for The Boeing Company Model 747 airplanes equipped with a main deck side cargo door (MDSCD). This AD was prompted by recent testing that indicates that intermodal containers, when loaded as cargo, under certain flight- load conditions, can shift and impact the adjacent fuselage frames. This AD requires revising the airplane flight manual (AFM) to incorporate limitations for carrying certain payloads. We are issuing this AD to prevent intermodal containers loaded in the offset method from shifting during flight gust loads and damaging fuselage frames, which could lead to the structural failure of the aft fuselage in flight and subsequent in-flight breakup of the airplane.