Summary
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 777-200 and -300 series airplanes equipped with Rolls-Royce RB211 Trent 800 engines. This proposed AD was prompted by reports of events related to thermal damage of the thrust reverser (T/R) inner wall on Rolls-Royce RB211 Trent 800 engines. This proposed AD would require replacing the bleed valve parts and tubing with new parts and tubing on the left and right engines. Additionally, this proposed AD would require installing Aero-Engine database (AEDB) software in the airplane information management system (AIMS) hardware. We are proposing this AD to eliminate T/R thermal damage caused by excessive heat downstream of the 8th stage IP8 exhaust ports, which could result in T/R structural failure. This failure could result in large pieces of the T/R or adjacent components departing the airplane. A separated T/R piece could result in a rejected takeoff (RTO) and cause asymmetric thrust andconsequent loss of control of the airplane during reverse thrust operations. Separated components could also cause structural damage to the airplane, damage to other airplanes, or injury to people on the ground.