Document ID: FAA-2014-0128-0009
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2015-10-02T04:00Z

[Federal Register Volume 80, Number 191 (Friday, October 2, 2015)]
[Rules and Regulations]
[Pages 59570-59575]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-24677]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2014-0128; Directorate Identifier 2013-NM-133-AD; 
Amendment 39-18278; AD 2015-19-16]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: 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.

DATES: This AD is effective November 6, 2015.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of November 6, 
2015.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may view this referenced service information 
at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., 
Renton, WA. For information on the availability of this material at the 
FAA, call 425-227-1221. It is also available on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2014-
0128.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2014-
0128; or in person at the Docket Management Facility between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this AD, the regulatory evaluation, any comments received, and 
other information. The address for the Docket Office (phone: 800-647-
5527) is Docket Management Facility, U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Kevin Nguyen, Aerospace Engineer, 
Propulsion Branch, ANM-140S, Seattle Aircraft Certification Office 
(ACO), FAA, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-
917-6501; fax: 425-917-6590; email: kevin.nguyen@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to The Boeing Company Model 
777 airplanes equipped with Rolls-Royce Trent 800 series engines. The 
NPRM published in the Federal Register on March 3, 2014 (79 FR 11725); 
corrected March 11, 2014 (79 FR 13592). The NPRM 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. The NPRM proposed to 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 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.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the NPRM (79 
FR 11725, March 3, 2014; corrected March 11, 2014 (79 FR 13592); and 
the FAA's response to each comment.

Request To Match Compliance Time

    Cathay Pacific requested that we ensure that the AD compliance date 
will be the same as the compliance time of Boeing Special Attention 
Service Bulletin 777-78-0051, Revision 3, dated August 23, 2012; or 
Boeing Special Attention Service Bulletin 777-78-0051, Revision 4, 
dated February 7, 2014. Cathay Pacific reasoned that paragraph (i) of 
the proposed AD specified compliance within 60 months after the 
effective date of the proposed AD, and both revisions of this service 
information specify a compliance time that is within 60 months after 
the Revision 3 date of the service bulletin.
    We infer that Cathay Pacific is requesting that we reduce the 
compliance time of this final rule to match the compliance time listed 
in the service information. We do not agree with the commenter's 
request. In developing an appropriate compliance time for this action, 
we considered not only the degree of urgency associated with addressing 
the subject unsafe condition, but the manufacturer's recommendation for 
an appropriate compliance time, the time required for the rulemaking 
process, the availability of required parts, and the practical aspect 
of installing the required modification within an interval of time that 
corresponds to the typical scheduled maintenance for the majority of 
affected operators. Under the provisions of paragraph (l) of this AD,

[[Page 59571]]

we may approve requests for adjustments to the compliance time, if data 
are submitted to substantiate that such an adjustment would provide an 
acceptable level of safety. We have not changed the AD in this regard.

Request To Define ``Serviceable'' To Include Pre-Boeing Service 
Bulletin 777-78-0051 Plug Assemblies

    Cathay Pacific requested that we revise paragraph (j) of the 
proposed AD; corrected March 11, 2014 (79 FR 13592) to define 
``serviceable'' plug assemblies. Cathay Pacific reasoned that both pre- 
and post-Boeing Service Bulletin 777-78-0051 plug assemblies can be 
installed, and the modification can be completed before the required 
compliance time of the NPRM (79 FR 11725, March 3, 2014; corrected 
March 11, 2014 (79 FR 13592)).
    We do not agree to revise paragraph (j) of this AD because 
serviceable assemblies are already defined in paragraph (h) of this AD. 
This definition applies to the entire AD. Also, pre- Boeing Service 
Bulletin 777-78-0051 plug assemblies do not meet the definition of 
serviceable, as specified in the service information.

Request To Revise Definition of a Serviceable Assembly

    American Airlines (AA) requested that we revise paragraph (h) of 
the proposed AD to add another definition: Serviceable plug assemblies, 
as those maintained in accordance with the operator's continued 
airworthiness maintenance program (CAMP), prior to issuance of Boeing 
Special Attention Service Bulletin 777-78-0051, Revision 3, dated 
August 23, 2012. AA explained that prior to release of Boeing Special 
Attention Service Bulletin 777-78-0051, Revision 3, dated August 23, 
2012, due to reported events of exhaust plug losses by other operators, 
AA recognized that multiple removals of the exhaust aft plug causes the 
3/16'' nutplate locking feature to wear out, which could then result in 
loss of the aft plug. As a result, AA implemented a maintenance program 
as part of its CAMP, which offers a level of safety equivalent to that 
of Boeing Special Attention Service Bulletin 777-78-0051, Revision 3, 
dated August 23, 2012. During every engine removal, for a refurbishment 
or overhaul shop visit, the pre-Boeing Special Attention Service 
Bulletin 777-78-0051, Revision 3, dated August 23, 2012, exhaust aft 
plug nutplates are replaced with new nutplates.
    In addition, AA stated that the holes are inspected for elongation 
and cracks in accordance with procedures equivalent to Boeing Special 
Attention Service Bulletin 777-78-0051 inspection procedures. Model 777 
Airplane Maintenance Manual Chapter 78-11-02-400-803-R00, requires that 
the minimum fastener run[hyphen]on torque of 2 in[hyphen]lbs is met 
during every installation of the aft exhaust plug. In addition, each of 
the exhaust aft plug fasteners receives a general visual check, using a 
ladder/stand and a bright light, every 150 flight hours. AA expressed 
that it is currently the largest Model 777-200 Trent 800 operator in 
the worldwide fleet and has not lost an exhaust aft plug due to loose 
or missing fasteners, as its CAMP demonstrates an equivalent level of 
safety to the service information.
    As an alternative, AA requested that we revise the NPRM (79 FR 
11725, March 3, 2014; corrected March 11, 2014 (79 FR 13592)) to 
include, as serviceable exhaust aft plugs, those maintained in 
accordance with the operator's own maintenance program, such as AA's 
approved CAMP prior to issuance of Boeing Special Attention Service 
Bulletin 777-78-0051, Revision 3, dated August 23, 2012, and to remain 
in service until the next engine removal for refurbishment or overhaul 
shop visit, or 60 months from the effective date of the AD, whichever 
is later.
    We do not agree to include the requested provision. The maintenance 
program described by AA is likely to be acceptable in lieu of direct 
compliance with portions of this AD; however, the description of that 
program provided in AA's comment is not sufficient to serve as 
engineering data for the FAA to approve as an optional method of 
compliance in this AD. Operators can submit a request for approval of 
an alternative method of compliance (AMOC), with a more detailed 
proposal to use the maintenance program, if sufficient data are 
submitted to substantiate that the change would provide an acceptable 
level of safety. We have not changed this AD in this regard.

Request To Change Compliance Time of Parts Installation Limitation

    Boeing and Cathay Pacific requested that we revise paragraph (j) of 
the proposed AD to change the installation limitation from the 
effective date of the AD to the compliance deadline for the AD. Boeing 
reasoned that paragraph (j) of the proposed AD currently creates an 
alternative and indeterminate compliance deadline. Boeing explained 
that during the compliance interval and prior to the AD deadline, 
operators may be required, due to unforeseen circumstances, to install 
a unit that is not a serviceable unit, and that under the current 
wording, this would unnecessarily ground the airplane.
    We do not agree to revise paragraph (j) of this AD to change the 
installation limitation from the effective date of the AD to the 
compliance date of the AD. Grace period compliance times are provided 
in ADs in recognition that an immediate unscheduled modification 
requirement would be disruptive. A grace period is included to give 
operators a reasonable period of time to schedule and perform actions 
that are required by the AD and that otherwise would not have occurred. 
A parts installation limitation is included in some cases to require 
that, if the parts affected by the AD are already being removed for a 
reason other than the AD itself, that opportunity to correct the unsafe 
condition should be taken. We determine whether such a parts 
installation limitation should be included in the AD, and what the 
specific requirements of the limitation will be, based on the risk 
level associated with the unsafe condition and the expected 
availability of required replacement parts.
    In this case, we made a determination that the risk warranted the 
consideration of a parts installation limitation. We also determined 
that sufficient parts would be available to meet that limitation, and 
that sufficient time to perform any required actions to make a nozzle 
assembly serviceable as defined in paragraph (h) of this AD would exist 
in situations where the nozzle might be removed in maintenance. 
Specifically, we considered the case of an unscheduled engine change 
where an operator may not have included a serviceable nozzle assembly 
with the replacement engine. Modification of a nozzle assembly to meet 
the definition of a serviceable nozzle can be performed in roughly the 
same or less elapsed time than it takes to perform the engine 
replacement itself. We did not foresee any other commonly occurring 
situation where an engine nozzle assembly would be removed for 
maintenance. However, as discussed in response to the comment issue 
``Request to Revise Definition of a Serviceable Assembly,'' if an 
operator specifically and adequately addresses the management of this 
unsafe condition within its CAMP, we will consider AMOC approvals to 
allow installation of nozzle assemblies that do not meet the definition 
of serviceable nozzle in paragraph (h) of this AD.
    We clarified paragraph (j) of this AD as a result of these 
comments. We considered the explanatory statements about the intent of 
the parts installation limitation language used in several

[[Page 59572]]

recent ADs, and determined that different language should be used in 
this case to more clearly convey the intent of the parts installation 
limitation contained in this AD. We have added the words ``or re-
install'' to paragraph (j) to clarify that any installation of a nozzle 
assembly, regardless of the reason for the removal of the nozzle 
assembly and regardless of the source of the replacement nozzle 
assembly, is subject to the parts installation limitation of paragraph 
(j) of this AD.

Request To Clarify Paragraph (j) of the Proposed AD

    AA requested that we clarify paragraph (j) of the proposed AD. AA 
explained that paragraph (j) of the proposed AD allows that only a 
serviceable turbine exhaust plug assembly may be installed on any 
airplane as of the effective date of this AD, while paragraph (i) of 
the proposed AD requires a compliance time within a certain time after 
the effective date of this AD, without any referral to serviceable 
turbine exhaust plug assembly. AA reasoned that as written, these steps 
are confusing and could lead operators to believe the actions required 
by the AD are due as of the effective date of this AD.
    We agree with the commenter and have clarified paragraph (j) of 
this AD by including references to paragraphs (h)(1) and (h)(2) of this 
AD.

Request To Clarify the AMOC Paragraph

    Boeing requested that we revise paragraph (k)(3) of the proposed AD 
(paragraph (l)(3) of this AD) to indicate that an AMOC, approved for a 
repaired serviceable unit is to be attached to, and travel with, the 
repaired serviceable unit. Boeing explained that the AMOC approval 
should apply to the deviation on the serviceable unit and thereby 
travel with the serviceable unit, which is rotable and could be 
installed on numerous airplanes during its service life. Boeing also 
explained that a unit repaired in accordance with an approved AMOC will 
fulfill the intent of airplane safety when the unit is installed on an 
airplane, and that the unit will be in compliance with the AD as long 
as the part is serviceable as defined by the AD.
    We agree with the commenter and have revised paragraph (l)(3) of 
this AD accordingly.

Request To Use the CAMP

    AA requested that we revise the NPRM (79 FR 11725, March 3, 2014; 
corrected March 11, 2014 (79 FR 13592)), to include language that 
allows the optional re-identification of the exhaust plug with the 
correct post-Boeing Special Attention Service Bulletin 777-78-0051, 
part number identity in accordance with a method approved by the 
operator's approved CAMP, as the CAMP provides an equivalent level of 
safety. AA explained that prior to the release of Boeing Special 
Attention Service Bulletin 777-78-0051, Revision 3, dated August 23, 
2012, AA implemented a maintenance program to install data plates on 
the forward and aft exhaust plug. The plates were installed because the 
manufacturer part number and serial number, which were chemical-etched 
on the exhaust plug skin by the manufacturer, were no longer legible. 
AA stated that the data plates contain the original part number, a 
company-assigned serial number, and the text ``MATCHED SET. DO NOT 
SEPARATE.'' AA added that the installed identification plates are in 
the same location as, but a different length than, the plates specified 
in Boeing Special Attention Service Bulletin 777-78-0051, Revision 3, 
dated August 23, 2012.
    We agree to allow alternative permanent part-marking methods. If 
the markings contain the required information and are permanent, the 
intent of the marking requirement is addressed, and additional 
flexibility is provided to operators. Therefore, part-marking methods 
for the CAMP might be approved, provided that the markings are 
permanent and contain the information specified in Boeing Special 
Attention Service Bulletin 777-78-0051, Revision 4, dated February 7, 
2014. We have added this information to paragraph (g) of this AD 
accordingly.

Request To Eliminate AMOC Approval Requirement for Previous Repairs

    AA requested that we revise paragraph (h) of the proposed AD, to 
allow repairs accomplished prior to the release of this AD, in 
accordance with Boeing instructions and approved per 14 CFR part 
121.379, or a Boeing ODA, to be included as acceptable repairs in this 
AD, without the requirement to obtain a Boeing ODA AMOC or Seattle 
Aircraft Certification Office AMOC approval.
    AA explained that, prior to release of the NPRM (79 FR 11725, March 
3, 2014; corrected March 11, 2014 (79 FR 13592)); exhaust aft plugs 
have received repairs at the exhaust aft plug mate line during 
inspection or during incorporation of Boeing Special Attention Service 
Bulletin 777-78-0051, Revision 3, dated August 23, 2012, utilizing 
procedures provided by Boeing without Boeing ODA approval; rather, the 
repair was approved per 14 CFR part 121.379. AA expressed that 
paragraph (h) of the proposed AD specifies using a repair method 
approved in accordance with the procedures specified in paragraph (k) 
of the proposed AD, and these previously accomplished repairs, which 
followed Boeing repair instructions, offer an equivalent level of 
safety to the NPRM.
    We partially agree with the request. We agree to add paragraph 
(l)(4) in this AD to eliminate the requirement for subsequent AMOC 
approval for repairs that were previously approved by the Boeing ODA, 
using an FAA Form 8100-9, and having met the requirements of paragraph 
(h) of this AD, for the definition of serviceable turbine exhaust plug 
assemblies. We are confident that the Boeing ODA repair approval 
process ensures that each repair is reviewed by qualified engineering 
staff with knowledge of the original airplane design and compliance 
substantiation. At the same time, we want to ensure that those repairs 
would have a configuration that meets the definition of serviceable 
turbine exhaust plug assemblies as defined in the service information. 
We have added paragraph (l)(4) in this AD to state that repairs 
approved prior to the effective date of this AD, by the Boeing ODA 
using FAA Form 8100-9, and having met the requirements of paragraph (h) 
of this AD for the definition of serviceable turbine exhaust plug 
assemblies, do not require AMOC approval.
    We disagree, however, to eliminate the AMOC approval requirement 
for repairs approved by other means. Even though Boeing Service 
Engineering may have provided a ``no technical objection'' statement, 
qualified engineering staff with knowledge of the original airplane 
design and compliance substantiation may not have been involved in 
evaluating the repair. We have not changed this AD in this regard.

Additional Changes to This AD

    We have revised this AD to refer to Boeing Special Attention 
Service Bulletin 777-78-0051, Revision 4, dated February 7, 2014, as 
the appropriate source of service information for the required actions. 
Among other things, this service information adds Group 2 airplanes to 
paragraph 1.E., ``Compliance;'' includes a maintenance records check; 
adds a general visual inspection to determine the diameter of the bolt 
used at the forward and aft plug interface; and adds applicable 
corrective actions--all of which we have clarified in new paragraph 
(g)(4) of this AD. Paragraphs (g)(3) and (c) of the proposed AD already 
accounted for the Group 2

[[Page 59573]]

airplanes defined in Boeing Special Attention Service Bulletin 777-78-
0051, Revision 4, dated February 7, 2014. Paragraph (g)(2) of the 
proposed AD accounted for the required actions.
    We have also added a new paragraph (k) to this AD to provide credit 
for certain actions, if those actions were performed before the 
effective date of this AD using Boeing Special Attention Service 
Bulletin 777-78-0051, Revision 3, dated August 23, 2012. We have 
redesignated the subsequent paragraphs of this AD accordingly.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this AD with the changes described previously and minor editorial 
changes. We have determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM (79 FR 11725, March 3, 2014; corrected March 11, 2014 (79 FR 
13592)) for correcting the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM (79 FR 11725, March 3, 2014; corrected 
March 11, 2014 (79 FR 13592)).
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Special Attention Service Bulletin 777-78-0051, 
Revision 4, dated February 7, 2014. Among other things, this service 
information adds Group 2 airplanes to paragraph 1.E., ``Compliance;'' 
includes a maintenance records check; adds a general visual inspection 
to determine the diameter of the bolt used at the forward and aft plug 
interface; and adds applicable corrective actions. This service 
information is reasonably available because the interested parties have 
access to it through their normal course of business or by the means 
identified in the ADDRESSES section of this AD.

Costs of Compliance

    We estimate that this AD affects 35 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Installation..........................  5 work-hours x $85 per                $0            $425         $14,875
                                         hour = $425.
General visual inspection.............  2 work-hours x $85 per                $0            $170          $5,950
                                         hour = $170.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary replacement 
that would be required based on the results of the inspection. We have 
no way of determining the number of aircraft that might need this 
replacement:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replacement (replacing the \3/16\-inch bolts   5 work-hours x $85 per hour =                $0             $425
 with \1/4\-inch bolts).                        $425.
----------------------------------------------------------------------------------------------------------------

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2015-19-16 The Boeing Company: Amendment 39-18278; Docket No. FAA-
2014-0128; Directorate Identifier 2013-NM-133-AD.

[[Page 59574]]

(a) Effective Date

    This AD is effective November 6, 2015.

(b) Affected ADs

    None.

(c) Applicability

    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.

(d) Subject

    Air Transport Association (ATA) of America Code 78, Engine 
Exhaust.

(e) Unsafe Condition

    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. 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 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.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Installation and General Visual Inspection

    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.

(h) Definition of Serviceable Assembly

    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.

(i) Exception to Service Information Specifications

    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.

(j) Parts Installation Limitation

    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.

(k) Credit for Previous Actions

    This paragraph provides credit for the actions specified in 
paragraph (g) of this AD, if those actions were performed before the 
effective date of this AD using Boeing Special Attention Service 
Bulletin 777-78-0051, Revision 3, dated August 23, 2012 (which is 
not incorporated by reference in this AD), provided that for Group 
1, Configuration 2, airplanes, on which the condition defined in 
Table 2 of paragraph 1.E., ``Compliance,'' of Boeing Special 
Attention Service Bulletin 777-78-0051, Revision 3, dated August 23, 
2012, was found (i.e., only \1/4\ inch diameter bolts are found 
installed at all 33 locations forward and aft plug interface), the 
re-identification of the forward and aft plug was done before 
further flight after the inspection.

(l) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in paragraph (m) of this AD. 
Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD if it is approved by the 
Boeing Commercial Airplanes Organization Designation Authorization 
(ODA) that has been authorized by the Manager, Seattle ACO, to make 
those findings. For a repair method to be approved, the repair must 
meet the certification basis of the airplane, and the approval must 
specifically refer to this AD. An AMOC approved as described in this 
paragraph for a specific serviceable nozzle assembly may be 
transferred with that nozzle assembly to another aircraft without an 
additional AMOC approval being required.
    (4) Repairs approved prior to the effective date of this AD by 
the Boeing ODA do not require AMOC approval if those repairs were 
approved using FAA Form 8100-9 and those repairs meet the definition 
of a serviceable assembly contained in the Accomplishment 
Instructions of Boeing Special Attention Service Bulletin 777-78-
0051, Revision 4, dated February 7, 2014.

(m) Related Information

    (1) For more information about this AD, contact Kevin Nguyen, 
Aerospace Engineer, Propulsion Branch, ANM-140S, Seattle Aircraft 
Certification Office (ACO) FAA, 1601 Lind Avenue SW., Renton, WA 
98057-3356; phone: 425-917-6501; fax: 425-917-6590; email: 
kevin.nguyen@faa.gov.
    (2) Service information identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraphs (n)(3) and (n)(4) of this AD.

(n) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Boeing Special Attention Service Bulletin 777-78-0051, 
Revision 4, dated February 7, 2014.
    (ii) Reserved.
    (3) For Boeing service information identified in this AD, 
contact Boeing Commercial Airplanes, Attention: Data & Services 
Management, P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; 
telephone

[[Page 59575]]

206-544-5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com.
    (4) You may view this service information at FAA, Transport 
Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For 
information on the availability of this material at the FAA, call 
425-227-1221.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on September 16, 2015.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-24677 Filed 10-1-15; 8:45 am]
 BILLING CODE 4910-13-P