Airworthiness Directives; The Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200 and -300 series airplanes equipped with Rolls-Royce Model RB211-Trent 800 engines. This AD was prompted by reports of thrust reverser (T/R) events related to thermal damage of the T/R inner wall. Depending on the airplane configuration, this AD requires a records review and applicable repetitive inspections, replacements, and installations of the T/R inner wall; and related investigative and corrective actions if necessary. This AD also requires installation of serviceable T/R halves, which would terminate the repetitive actions. This AD also requires revising the inspection or maintenance program by incorporating new airworthiness limitations. We are issuing this AD to detect and correct a degraded T/R inner wall panel. A degraded T/R inner wall panel could lead to failure of the T/R 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 a T/R inner wall overheats, separated components could cause structural damage to the airplane, damage to other airplanes, or possible injury to people on the ground.