Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Notice of proposed rulemaking (NPRM).

We propose to adopt a new airworthiness directive (AD) for The Boeing Company Model airplanes equipped with Rolls-Royce Trent 800 series engines. This proposed AD was prompted by reports of in-flight separation of the aft plug from the forward plug, which are the two parts of the turbine exhaust plug assembly. This proposed AD would require installation of a serviceable turbine exhaust plug assembly (for certain airplanes), and a general visual inspection (for certain airplanes) to determine the diameter of the bolt used at the forward and aft plug interface, and applicable corrective actions. We are proposing this AD to prevent separation of the forward plug from the aft plug of the turbine exhaust plug assembly, which could result in parts departing the airplane and hitting the empennage or hitting a person on the ground, and destabilizing the airplane during a critical flight phase; parts remaining on a runway could cause damage to another airplane.

View PDF