Airworthiness Directives; the Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for certain the Boeing Company Model 777-200, -200LR, and -300ER series airplanes. This AD was prompted by a report from the manufacturer indicating that the lowered ceiling support structure of Section 41, in airplanes incorporating the overhead space utilization (OSU) option, was found to be under-strength when subjected to a 9.0 g forward load. This AD requires installing new structural members, tie rod(s), and attach fittings on the left and right sides of the lowered ceiling support structure. We are issuing this AD to prevent the forward lowered ceiling panels and support structure from becoming dislodged during a 9.0 g forward load and consequent injury to personnel or interference with an emergency evacuation.