Airworthiness Directives; The Boeing Company Model 777-200 Series Airplanes

We are adopting a new airworthiness directive (AD) for certain Model 777-200 series airplanes. This AD requires installing a new insulation blanket on the latch beam firewall of each thrust reverser (T/R) half. This AD results from an in-flight shutdown due to an engine fire indication; an under-cowl engine fire was extinguished after landing. The cause of the fire was uncontained failure of the starter in the engine core compartment; the fire progressed into the latch beam cavity and was fueled by oil from a damaged integrated drive generator oil line. We are issuing this AD to prevent a fire from entering the cowl or strut area, which could weaken T/R parts and result in reduced structural integrity of the T/R, possible separation of T/R parts during flight, and consequent damage to the airplane and injury to people or damage to property on the ground.