Airworthiness Directive · Amendment 39-18278 · Engine exhaust
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 777-200, -200LR, -300,-300ER, and 777F series airplanes; certificated in any category; equipped with Rolls-Royce Trent 800 series engines.
We are adopting a new airworthiness directive (AD) for The Boeing Company Model 777 airplanes equipped with Rolls-Royce Trent 800 series engines. This AD was prompted by reports of in-flight separation of the engine's aft plug from the forward plug, which are the two parts of the turbine exhaust plug assembly. This AD requires 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 issuing this AD to prevent separation of the aft plug from the forward plug of the turbine exhaust plug assembly, which could result in parts departing the airplane and hitting the empennage, and destabilizing the airplane during a critical flight phase. In addition, parts remaining on a runway could pose a hazard to another airplane.
At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 777-78-0051, Revision 4, dated February 7, 2014, except as provided by paragraph (i) of this AD, do the applicable actions specified in paragraphs (g)(1), (g)(2), (g)(3), and (g)(4) of this AD, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-78-0051, Revision 4, dated February 7, 2014. Alternative part marking methods are allowed for the requirements of this paragraph, if approved by the FAA principal maintenance inspector, provided that the markings are permanent and contain the information required by Boeing Special Attention Service Bulletin 777-78-0051, Revision 4, dated February 7, 2014.
(1) For airplanes identified as Group 1, Configuration 1, in Boeing Special Attention Service Bulletin 777-78-0051, Revision 4, dated February 7, 2014: Install a serviceable turbine exhaust plug assembly.
(2) For airplanes identified as Group 1, Configurations 2 and 3, in Boeing Special Attention Service Bulletin 777-78-0051, Revision 4, dated February 7, 2014: Do a general visual inspection to determine the diameter of the bolt used at the forward and aft plug interface, and before further flight, do all applicable corrective actions.
(3) For airplanes listed in paragraph (c) of this AD that are not listed in the “Effectivity” section of Boeing Special Attention Service Bulletin 777-78-0051, Revision 4, dated February 7, 2014: Do a general visual inspection to determine if a serviceable turbine exhaust plug assembly is installed. If a serviceable turbine exhaust plug assembly is not installed, before further flight, install a serviceable turbine exhaust plug assembly.
(4) For airplanes identified as Group 2, in Boeing Special Attention Service Bulletin 777-78-0051, Revision 4, dated February 7, 2014: Do a maintenance records check to determine affected turbine exhaust plug assemblies, and for affected assemblies, do a general visual inspection to determine the diameter of the bolt used at the forward and aft plug interface, and before further flight, do all applicable corrective actions.
For the purposes of this AD, an acceptable serviceable turbine exhaust plug assembly must meet the conditions specified in paragraph (h)(1) or (h)(2) of this AD.
(1) A new assembly with part number 314W5520-22.
(2) A serviceable assembly as defined in the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-78-0051, Revision 4, dated February 7, 2014; except, for any assembly on which the actions specified in Part 2 or Part 3 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-78-0051, Revision 4, dated February 7, 2014, are done, and Boeing Special Attention Service Bulletin 777-78-0051, Revision 4, dated February 7, 2014, specifies to contact Boeing for repair instructions, this AD requires repair before further flight, using a method approved in accordance with the procedures specified in paragraph (l)(1) of this AD.
Where paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 777-78-0051, Revision 4, dated February 7, 2014, specifies a compliance time “after the Revision 3 date of this service bulletin,” or “after the Revision 4 date of this service bulletin,” this AD requires compliance within the applicable time after the effective date of this AD.
As of the effective date of this AD, only a serviceable turbine exhaust plug assembly that meets the requirements of paragraph (h)(1) or (h)(2) of this AD may be installed or reinstalled on any airplane.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
