Airworthiness Directives; Boeing Model 777-200 and -300 Series Airplanes Equipped With Rolls Royce Model RB211 TRENT 800 Engines

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 777-200 and -300 series airplanes. This AD requires inspecting the thrust reversers for damage of the insulation blankets, the inner wall, and the compression and drag link fittings; and repair if necessary. This AD also requires applying sealant to certain areas of the thrust reverser. This AD is prompted by two reports of thrust reverser failure; investigation revealed that the inner wall of the thrust reversers had collapsed from exposure to hot engine core compartment air. We are issuing this AD to prevent failure of a thrust reverser and adjacent components and their consequent separation from the airplane, which could result in a rejected takeoff (RTO) and cause asymmetric thrust and consequent loss of control of the airplane during reverse thrust operation. If an RTO does not occur, these separated components could cause structural damage to the airplane or damage to other airplanes and possible injury to people on the ground.