Rule2023-04024
Airworthiness Directives; The Boeing Company Airplanes
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
February 28, 2023
Effective
April 4, 2023
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 777 airplanes. This AD was prompted by fuel system reviews conducted by the manufacturer. This AD requires, depending on the airplane configuration, installation of Teflon sleeves, cap sealing of fasteners, detailed inspections, and corrective actions. This AD also requires revising the existing maintenance or inspection program, as applicable, to incorporate more restrictive airworthiness limitations (AWLs). The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 88 Issue 39 (Tuesday, February 28, 2023)</title>
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[Federal Register Volume 88, Number 39 (Tuesday, February 28, 2023)]
[Rules and Regulations]
[Pages 12550-12557]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-04024]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2022-0810; Project Identifier AD-2021-01238-T;
Amendment 39-22329; AD 2023-03-04]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all
The Boeing Company Model 777 airplanes. This AD was prompted by fuel
system reviews conducted by the manufacturer.
[[Page 12551]]
This AD requires, depending on the airplane configuration, installation
of Teflon sleeves, cap sealing of fasteners, detailed inspections, and
corrective actions. This AD also requires revising the existing
maintenance or inspection program, as applicable, to incorporate more
restrictive airworthiness limitations (AWLs). The FAA is issuing this
AD to address the unsafe condition on these products.
DATES: This AD is effective April 4, 2023.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of April 4,
2023.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2022-0810; or in person at Docket Operations between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD
docket contains this final rule, any comments received, and other
information. The address for Docket Operations is U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
Material Incorporated by Reference:
<bullet> For service information identified in this final rule,
contact Boeing Commercial Airplanes, Attention: Contractual & Data
Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA
90740-5600; telephone 562-797-1717; website <a href="http://myboeingfleet.com">myboeingfleet.com</a>.
<bullet> You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 2200 South
216th St., Des Moines, WA. For information on the availability of this
material at the FAA, call 206-231-3195. It is also available at
<a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2022-0810.
FOR FURTHER INFORMATION CONTACT: Kevin Nguyen, Aerospace Engineer,
Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des
Moines, WA 98198; phone and fax: 206-231-3555; email:
<a href="/cdn-cgi/l/email-protection#cda6a8bba4a3e3a3aab8b4a8a38dabacace3aaa2bb"><span class="__cf_email__" data-cfemail="bfd4dac9d6d191d1d8cac6dad1ffd9dede91d8d0c9">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to all The Boeing Company
Model 777 airplanes. The NPRM published in the Federal Register on July
26, 2022 (87 FR 44285). The NPRM was prompted by fuel system reviews
conducted by the manufacturer. In the NPRM, the FAA proposed to
require, depending on the airplane configuration, installation of
Teflon sleeves, cap sealing of fasteners, detailed inspections, and
corrective actions. The FAA also proposed to require revising the
existing maintenance or inspection program, as applicable, to
incorporate more restrictive AWLs. The FAA is issuing this AD to
address arcing inside the main and center fuel tanks in the event of a
fault current or lightning strike, which, in combination with flammable
fuel vapors, could result in a fuel tank explosion and consequent loss
of the airplane.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from The Air Line Pilots Association,
International (ALPA), who supported the NPRM without change.
The FAA received additional comments from seven commenters,
including American Airlines (AAL), Boeing, Emirates, Royal Dutch
Airlines (KLM), Air France Industries (AFA), FedEx, and United Airlines
(UAL). The following presents the comments received on the NPRM and the
FAA's response to each comment.
Request To Require a Later Revision of the Service Information
AFA, KLM, and UAL requested that Boeing Alert Service Bulletin 777-
57A0050, Revision 7 (SB 777-57A0050, Revision 7), be mandated by the
final rule instead of Boeing Alert Service Bulletin 777-57A0050,
Revision 6, dated August 18, 2021 (SB 777-57A0050, Revision 6). AFA
asserted that following release of SB 777-57A0050, Revision 6, they
discussed with Boeing certain errors in SB 777-57A0050, Revision 6,
that will be corrected in SB 777-57A0050, Revision 7.
KLM explained that the NPRM contains technical detail that should
not be included in a high level regulation such as an AD, and that it
could possibly lead to confusion and mistakes by airline staff. KLM
stated that, for example, in paragraphs (h)(2), (3), and (4) of the
proposed AD, it does not specify exactly which seven fasteners should
be inspected and sealed. KLM noted that according to Figures 172, 173,
174, 175, 176, 179 and 180 of SB 777-57A0050, Revision 6, there are
more than seven fasteners located on the inboard side of rib no. 9 and
the proposed AD does not specify exactly which seven fasteners should
be inspected/sealed. KLM requested that the FAA clarify which seven
fasteners should be inspected/sealed exactly and recommend that the
service information should first be revised by the original equipment
manufacturer (OEM) and requested that the FAA allow the OEM to revise
the service information before issuing the final rule.
UAL requested that the final AD mandate SB 777-57A0050, Revision 7,
to ensure an additional work package is included for airplanes that
accomplished SB 777-57A0050, Revision 6, without the exceptions
specified in paragraph (h) of the proposed AD. UAL explained that
paragraph (h) of the proposed AD provides exceptions to SB 777-57A0050,
Revision 6, for known errors within the service bulletin. UAL stated
that since SB 777-57A0050, Revision 6, was an alternative method of
compliance (AMOC) to paragraphs (g)(1), (i), (j), and (k)(1) through
(3) of AD 2017-11-14, Amendment 39-18913 (82 FR 25954, June 6, 2017)
(AD 2017-11-14), operators may have previously complied with it without
the deviations or exceptions provided in paragraph (h) of the proposed
AD. UAL stated this proposed AD does not address how to correct that
condition. UAL noted that Boeing is developing SB 777-57A0050, Revision
7, to address the exceptions in paragraph (h) of the proposed AD, and
to include new Groups and Configurations for airplanes that have
accomplished SB 777-57A0050, Revision 6. UAL further stated that an
additional work package is required to inspect and/or correct the
erroneous work instructions from SB 777-57A0050, Revision 6.
The FAA does not agree with the request to refer to SB 777-57A0050,
Revision 7, because it is not known when Revision 7 will be available.
The FAA is aware of the errors of SB 777-57A0050, Revision 6, as
identified by the commenters, and the exceptions specified in paragraph
(h) of this AD address errors that affect addressing the unsafe
condition. The FAA notes that paragraphs (h)(2) through (4) of the
proposed AD provided adequate information to identify the location of
the fasteners in Figures 172, 173, 174, 175, 176, 179 and 180 of SB
777-57A0050, Revision 6. However, the FAA has added additional
information to paragraphs (h)(2) through (4) of this AD to help clarify
the location of the affected fasteners by specifying if the fasteners
are adjacent to the right or left side of the identified fasteners. As
specified in the comment responses that follow, other errors are
addressed by the exceptions specified in paragraphs (h)(5) through (7)
of this AD. The FAA
[[Page 12552]]
considers SB 777-57A0050, Revision 6, and the information provided in
paragraphs (h)(2) through (7) of this AD as adequate accomplishment
instructions to correct the unsafe condition. As specified in paragraph
(l)(1) of this AD, accomplishment of the actions required by paragraph
(g) of this AD terminates the requirements of paragraphs (g)(1), (i),
and (j) of AD 2017-11-14. Therefore, the FAA considers that delaying
this AD action until the availability of Revision 7 of SB 777-57A0050
would not be warranted.
Request To Include Service Bulletin Revision Information
AFA expressed that certain airplane maintenance manual (AMM) task
instructions relating to ``POST-SB'' should include information about
the revision of Boeing Alert Service Bulletin 777-57A0050 that was
accomplished. As part of AFA's request to mandate SB 777-57A0050,
Revision 7, AFA explained that the AMM TASK 28-22-00-210-801
instructions, related to Airworthiness Limitations (AWLs) 28-AWL-31 and
28-AWL-32, depend on the service bulletin status. However, AFA noted
the AMM task is only marked ``POST-SB,'' and there is no mention of the
service bulletin revision.
The FAA does not agree with this request because AMM task 28-22-00-
210-801 is not required by this AD. AMM task 28-22-00 is referenced in
AWLs 28-AWL-31 and 28-AWL-32, which specify in the applicability column
``Airplanes that have incorporated Service Bulletin 777-57A0050.'' As
required by paragraph (i) of this AD, operators must revise the
existing maintenance or inspection program, as applicable, to
incorporate the information for 28-AWL-31 and 28-AWL-32. However, AWLs
28-AWL-31 and 28-AWL-32 do not specify the service bulletin revision in
the applicability column; therefore, there is not a requirement to
identify AMMs as ``POST-SB'' with a service bulletin revision. No
changes have been made to this AD based on this request.
Request To Clarify Compliance Time
AFA requested additional clarification of the compliance time. AFA
stated that earlier revisions of SB 777-57A0050, have different
scheduling rules, and that the instructions given in SB 777-57A0050,
Revision 6, depend on the accomplished work.
The FAA agrees with providing clarification regarding the
compliance time. The FAA has previously issued AD 2011-26-03, Amendment
39-16893 (76 FR 78138, December 16, 2011) (AD 2011-26-03), which
mandated Boeing Alert Service Bulletin 777-57A0050, Revision 2, dated
May 14, 2009 (SB 777-57A0050, Revision 2). Boeing Alert Service
Bulletin 777-57A0050, Revision 3, dated February 18, 2014 (777-57A0050,
Revision 3) was approved as an AMOC with the requirements of AD 2011-
26-03. That AD was superseded by AD 2017-11-14, which retained the
requirements of AD 2011-26-03 and also mandated Boeing Alert Service
Bulletin 777-57A0050, Revision 4, dated September 28, 2015 (SB 777-
57A0050, Revision 4) for certain groups of airplanes specified in that
revision. After issuance of AD 2017-11-14, the FAA determined that a
new AD would be necessary to mandate a later revision of Boeing Alert
Service Bulletin 777-57A0050 because more airplanes are affected by the
identified unsafe condition, and additional work is required for
airplanes on which earlier revisions of the service information has
been incorporated.
Paragraph 1.E., ``Compliance,'' of SB 777-57A0050, Revision 6,
specifies the compliance times for all groups and configurations,
except as specified in paragraph (h)(1) of this AD. For example, for
those airplanes in SB 777-57A0050, Revision 6, that have already been
identified in SB 777-57A0050, Revisions 2, 3, or 4, the compliance
times specified in AD 2017-11-14 would apply. Specifically, for
airplanes identified in SB 777-57A0050, Revision 2 or 3, the actions
specified in SB 777-57A0050, Revision 2 or 3 should have been
accomplished within 60 months after January 20, 2011 (the effective
date of AD 2010-24-12, Amendment 39-16531 (75 FR 78588, December 16,
2010)). For airplanes identified in SB 777-57A0050, Revision 4 but not
in earlier revisions, the actions specified in SB 777-57A0050, Revision
4 should have been accomplished within 60 months after July 11, 2017
(the effective date of AD 2017-11-14). For the rest of the airplane
groups and configurations identified in SB 777-57A0050, Revision 6, the
actions specified must be accomplished within 60 months after the
effective date of this AD. Operators should also note that paragraph
(l)(1) of this AD explains that accomplishment of the actions required
by paragraph (g) of this AD terminates paragraphs (g)(1), (i), and (j)
of AD 2017-11-14.
Request To Add Credit for Previous Actions
FedEx requests the addition of a ``Credit for Previous Action''
paragraph to any final AD to ensure previous modifications per SB 777-
57A0050, Revision 5, or earlier revisions do not have to be repeated.
FedEx stated that they are already doing the applicable added tasks
from the SB 777-57A0050, Revision 6, which has been approved as an AMOC
to AD 2017-11-14 and expressed concern that the required actions in
paragraph (g) of the proposed AD do not account for prior maintenance
actions done to comply with AD 2017-11-14.
The FAA declines to provide credit for the accomplishment of an
earlier service bulletin revision, because accomplishing the actions
specified in a revision earlier than SB 777-57A0050, Revision 6, on an
airplane does not necessarily mean that all applicable actions
specified in SB 777-57A0050, Revision 6, were accomplished on that
airplane to address the unsafe condition. The groups and configuration
in SB 777-57A0050, Revision 6, are dependent on which actions have
already been accomplished in accordance with earlier revisions.
Operators are required to determine whether additional work is required
by SB 777-57A0050, Revision 6, on each affected airplane that has
incorporated the actions specified in an earlier revision of the
service bulletin. If no additional work is required to address the
unsafe condition, then that airplane is in compliance with this new AD.
This AD has not been changed with regard to this request.
Request To Include a New Exception
AAL requested that paragraph (h) of the proposed AD include an
exception to exclude Group 1 through 4 from Work Package 28 of Boeing
Alert Service Bulletin 777-57A0050, Revision 6, because that work
package is not applicable to Groups 1 through 4. AAL stated that Boeing
has confirmed this to be accurate. AFA also stated that Work Package 28
is not applicable to Group 1 through 4.
The FAA has confirmed with Boeing that the error described by the
commenters exists in the service information. The FAA has added
paragraph (h)(5) to this AD, which reads ``Where Boeing Alert Service
Bulletin 777-57A0050, Revision 6, dated August 18, 2021, specifies Work
Package 28 as applicable to Group 1 through 4, and Group 8, this AD
does not require accomplishment of Work Package 28 for Group 1 through
4.''
Request To Clarify Access Steps for Work Packages 37, 38 and 39
AFA requested that the access steps for Work Packages 37, 38, and
39 of Boeing Alert Service Bulletin 777-57A0050, Revision 6, be
clarified. AFA stated that for Model 777-200, -200ER, and -300 series
airplanes, the rib 9 cap
[[Page 12553]]
sealing location is located in the dry-bay. AFA stated that Boeing
confirmed that access door 532AB for the dry bay should be used to
access the location for Figure 172, and confirmed fuel tank purging is
not necessary for Work Package 37. AFA also stated that for Model 777-
200LR and -300ER series airplanes, the rib 9 cap sealing location is
located in the center fuel tank. AFA stated that Boeing confirmed that
access door 531AB for the center fuel tank should be used to access the
location for Figure 172, and confirmed the center fuel tank should be
purged for Work Package 37.
AFA also stated that for Group 12, 14 through 41, 44 through 48, 55
through 57, 59-83, in Work Packages 38 and 39 of Boeing Alert Service
Bulletin 777-57A0050, Revision 6, Boeing agreed that at the rib 9 front
spar location, access door 531CB/631CB would be sufficient, and purge/
ventilation of the center tank would be necessary.
The FAA acknowledges that different access doors might be used for
certain airplanes for a given work package. As specified in Note 11. of
paragraph 3.A. ``General,'' of Boeing Alert Service Bulletin 777-
57A0050, Revision 6: ``If it is necessary to remove more parts for
access, you can remove those parts. If you can get access without
removing identified parts, it is not necessary to remove all of the
identified parts.'' The removal of access doors and purging of fuel
tanks are not actions that address the identified unsafe condition. The
FAA has determined delaying this final rule by adding exceptions to
identity applicable access doors and corresponding fuel tanks, as well
as corresponding procedures, is not warranted. The FAA has not changed
this AD in this regard. However, in order to not purge a specific tank
that is specified in a work package or purge the tank for a different
access door, the FAA has added paragraph (h)(7) to this AD that
specifies ``Where the Accomplishment Instructions of Boeing Alert
Service Bulletin 777-57A0050, Revision 6, dated August 18, 2021,
specifies to purge specific fuel tanks (right, left, or center),
operators must purge the applicable fuel tank for which access inside
the fuel tank is needed to apply cap sealing on the affected
fasteners.''
Request To Not Require Work Package 38 for Certain Groups
AFA stated that Boeing confirmed that for Group 1 through 4
airplanes, Work Package 38 of Boeing Alert Service Bulletin 777-
57A0050, Revision 6, provides the same instructions as Work Package 37,
and is not needed if Work Package 37 is accomplished.
The FAA confirmed with Boeing that Work Package 38 is not necessary
for Group 1 to 4 provided Work Package 37 has been accomplished. The
FAA has added paragraph (h)(6) to this AD to clarify that for Group 1
through 4 airplanes on which Work Package 37 has been accomplished,
Work Package 38 is not required.
Request To Refer to Latest Maintenance Planning Document (MPD) or Delay
Publication of the Final Rule
Boeing, and Emirates requested that the proposed AD be revised to
refer to the latest MPD. In addition, KLM, requested that the final
rule be delayed until a later MPD is published that addresses certain
discrepancies.
Boeing requested that the final rule be issued after the latest MPD
revision has been approved by the FAA and published, and that paragraph
(j) of the proposed AD be deleted. Boeing requested that the AD be
posted following the approval of the revised MPD. Boeing explained that
paragraph (j) of the proposed AD refers to changes prescribed by the
FAA within AWL No. 28-AWL-31 and 28-AWL-32. Since these changes will
have likely been approved by the FAA and published in the 777 MPD prior
to the AD being posted, Boeing asserted that there will be no need for
these AWL sub-paragraphs to be specifically called out in the AD.
Emirates requested that the Boeing MPD document D622W001-9, dated
March 2022, referenced in paragraphs (i) and (j) of the proposed AD be
replaced by the revision dated July 2022. Emirates explained that
paragraphs (i) and (j) of the proposed AD refer to ``Airworthiness
Limitations (AWLs) and Certification Maintenance Requirements (CMRs),
D622W001-9, dated March 2022'' while the latest revision of this MPD
document is dated July 2022.
KLM requested that the AD not be issued until after the subject MPD
is revised by the OEM or that the FAA explain the reason why it should
not be delayed.
The FAA agrees to refer to the latest MPD. Airworthiness
Limitations (AWLs) and Certification Maintenance Requirements (CMRs),
D622W001-9, dated August 2022, of Boeing 777 200/200LR/300/300ER/777F
Maintenance Planning Data (MPD) Document, has been published, and it
contains corrections that address the exceptions given in paragraph (j)
of the proposed AD. Paragraph (i) of this AD has been updated to
include this revision. Paragraph (j) of this AD has also been changed
to give credit for the March 2022, June 2022, and July 2022 revisions
of the MPD, provided that the corrections specified in paragraphs
(j)(1) through (4) of this AD are met.
Request To Clarify Applicability for an AWL Task
KLM requested that the FAA clarify an applicability for an AWL
task. KLM stated paragraphs (j)(1) through (4) of the proposed AD
provides details of changes to the content of the MPD document (ALI and
CMR), which includes changes to the applicability for certain
paragraphs of that document. KLM stated AWL 28-AWL-32 was already part
of AD 2021-24-12, Amendment 39-21833 (86 FR 73660, December 28, 2021)
(AD 2021-24-12), which has an applicability of ``The Boeing Company
Model 777-200, -200LR, -300, -300ER, and 777F series airplanes,
certificated in any category, having line numbers (L/Ns) 1 through 1609
inclusive.'' KLM stated paragraphs (j)(1) through (4) of the proposed
AD narrow this applicability down or widens it without AD 2021-24-12
being superseded. KLM concluded this will lead to confusion.
The FAA notes that paragraph (j) of the proposed AD does not affect
any aspect of AD 2021-24-12. The applicability of AD 2021-24-12
identifies the airplanes affected by the requirements of that AD.
Paragraph (j) of the proposed AD clarifies information for certain
steps within an AWL. Compliance with each AWL must be accomplished
based on the applicability specified in the Applicability block of each
AWL. The applicability of the AD affects whom must incorporate that AWL
into their maintenance or inspection program. The applicability of an
AWL neither affects nor is affected by the applicability of the AD that
mandated the incorporation of that AWL into the maintenance or
inspection program, unless specifically stated in an exception of the
regulatory text of an AD.
Paragraph (j) of the proposed AD does not change the applicability
block of AWL No. 28-AWL-31 and No. 28-AWL-32. Paragraph (j) of the
proposed AD is just intended to provide a clear definition of the
affected models and affected airplane line number ranges for certain
paragraphs or steps within AWL No. 28-AWL-31 and 28-AWL-32. Due to
unclear title descriptions, there was confusion as to what the
applicable affected models were for those paragraphs. As a result,
paragraph (j) was added to the proposed AD to provide clarification on
the affected models.
[[Page 12554]]
As stated previously, the FAA has redesignated paragraph (j) of the
proposed AD as a credit paragraph since the latest revision of the MPD
incorporates those changes. The information in paragraph (j) of this AD
will only be necessary if an MPD dated earlier than August 2022 is
used. Compliance with the requirements of both paragraph (i) of this AD
and paragraph (g) of AD 2021-24-12 can be accomplished by using
Airworthiness Limitations (AWLs) and Certification Maintenance
Requirements (CMRs), D622W001-9, dated August 2022, of Boeing 777 200/
200LR/300/300ER/777F Maintenance Planning Data (MPD) Document.
Paragraph (l)(2) of this AD specifies that accomplishment of the
revision required by paragraph (i) of this AD to incorporate the
information for 28-AWL-31 and 28-AWL-32 terminates the requirements of
paragraphs (g)(6) and (h) of AD 2021-24-12.
Request for Clarification of Compliance Time
Emirates asked whether airplanes need to be inspected again within
60 months after the effective date of the proposed AD per paragraph
(i)(2) of the proposed AD when those airplanes have already been
inspected in accordance with AWL No. 28-AWL-32 based on the initial
compliance time specified in paragraph (g)(6) of AD 2021-24-12.
Emirates did not ask for any specific change.
Although the commenter did not ask for a change, the FAA notes that
paragraph (i)(1) and (2) of the proposed AD should provide credit for
the inspection that has already been performed under the initial
compliance time specified in paragraph (g)(6) of AD 2021-24-12. Without
this credit, an airplane inspected under the initial compliance time
specified in paragraph (g)(6) of AD 2021-24-12 may need to be re-
inspected under the initial compliance time specified in paragraph
(i)(1) or (2) of the proposed AD. This is not the intent of paragraphs
(i)(1) and (2) of the proposed AD. To give credit for the inspection
already accomplished under the initial compliance time specified in
paragraph (g)(6) of AD 2021-24-12, the FAA has revised paragraphs
(i)(1) and (2) of this AD to include ``within 3,750 days after the most
recent inspection was performed as specified in AWL No. 28-AWL-32'' as
part of the initial compliance time.
Request for Alternate Teflon Sleeve Solution
Emirates stated that an alternate sleeve should be part of the next
service bulletin revision, and accepted as an alternative in the
proposed AD. Emirates stated that following release of SB 777-57A0050,
Revision 6, there was a worldwide material shortage of TFE-2X Standard
Wall--TEFLON SLEEVE 1 inch diameter. Emirates stated that Boeing
identified M23053/12 Class 2 and M23053/12 Class 5 as suitable
alternatives, depending on the diameter of the wire bundles.
According to Emirates, Boeing stated the following: M23053/12 Class
2 sleeves are a suitable alternative for the TFE-2X Standard Wall
sleeve for wire bundles up to 1 inch in diameter and noted the sleeves
are listed as an alternative in the standard wiring practices manual
(SWPM) Section 20-00-11 Table 31. Boeing advised that they are working
on a Global AMOC for alternative sleeve options for wire bundles
greater than 1 inch in diameter. For the larger bundles, Boeing
proposed using thinner M23053/12 Class 5 sleeves (for example M23053/
12-519-C) and wrapping them twice around the bundle, which provides the
same wall thickness as the Class 2 Standard Wall sleeves. Boeing
concluded that because this double-wrapped installation will require an
FAA AMOC approval, Boeing needs to be notified of this deviation.
The FAA does not agree to include alternative sleeving in this AD.
The FAA will review alternative sleeving if it is included in the next
service bulletin revision or if Boeing or an operator submits an AMOC
request under the provisions of paragraph (m) of this AD. The FAA will
consider requests for alternate sleeving if sufficient data are
submitted to substantiate that the change would provide an acceptable
level of safety.
Request To Remove ``Before Further Flight''
FedEx objected to the last sentence of paragraph (g) of the
proposed AD, ``Do all applicable corrective actions before further
flight.'' The FAA infers that FedEx requested that the FAA remove the
sentence. FedEx asserted that the last sentence of paragraph (g) of the
proposed AD is ambiguous since SB 777-57A0050, Revision 6, does not
specifically define what actions are ``corrective actions,'' and it has
the potential to immediately ground aircraft. As an example, FedEx
noted that for Work Package 23 of the Accomplishment Instructions of SB
777-57A0050, Revision 6, requires installation of teflon sleeves in
accordance with multiple figures without any prior inspection. Thus,
Work Package 23 could be interpreted as a ``corrective action'' which
is required prior to further flight. FedEx stated that the requirement
in paragraph (g) of the proposed AD to ``do all applicable actions'' is
sufficient since the associated service bulletin has specific actions
to cap seal fasteners before putting the aircraft back to a serviceable
condition.
The FAA acknowledges that the last sentence in paragraph (g) of the
proposed AD, ``Do all applicable corrective actions before further
flight,'' is confusing as used in this AD. In certain ADs, the standard
language, ``corrective actions,'' is defined in the preamble of the AD
and those are typically ``on-condition'' actions required to be
performed after the primary action (e.g., inspections). The ``before
further flight'' compliance time is included to make sure that the
corrective actions would be accomplished without any delay once the
inspection is accomplished. The FAA has determined that this
requirement is not necessary for this AD. The service information
mandated by this AD requires an inspection for certain groups of
airplanes to determine the installation configuration. Such an
inspection is not required for certain other groups of airplanes since
their installation configuration is already known. For all groups of
airplanes, the FAA has determined that accomplishing all applicable
actions within the compliance time would adequately address the safety
concern. Therefore, the FAA has removed the sentence ``Do all
applicable corrective actions before further flight'' from paragraph
(g) of this AD. The ``applicable corrective actions'' are included in
the ``all applicable actions (i.e., installation of Teflon sleeves, cap
sealing of fasteners, detailed inspections, and corrective actions)''
language specified in paragraph (g) of this AD and therefore must be
done within the applicable compliance time specified in Boeing Alert
Service Bulletin 777-57A0050, Revision 6.
Conclusion
The FAA reviewed the relevant data, considered any comments
received, and determined that air safety requires adopting this AD as
proposed. Accordingly, the FAA is issuing this AD to address the unsafe
condition on these products. Except for minor editorial changes, and
any other changes described previously, this AD is adopted as proposed
in the NPRM. None of the changes will increase the economic burden on
any operator.
[[Page 12555]]
Related Service Information Under 1 CFR Part 51
The FAA reviewed Boeing Alert Service Bulletin 777-57A0050,
Revision 6, dated August 18, 2021. This service information specifies
applicable actions that vary depending on the airplane configuration,
such as procedures for the installation of Teflon sleeves, cap sealing
of fasteners, detailed inspections, and corrective actions. The
detailed inspection of and installation of Teflon sleeves includes
various locations, such as the rear spar wire bundles, inboard and
outboard front spar wire bundles, wing-to-body fairing and
environmental control system (ECS) bay wire bundles, front and rear
spar bulkhead wire bundles, and wing rear spar wire bundles. The
detailed inspection of and cap sealing of fasteners include fasteners
in the center fuel tank, left and right main fuel tanks, and right
cheek portion of the center fuel tank. Corrective actions include
installing Teflon sleeve, installing clamp, and cap sealing fasteners.
The FAA also reviewed Section 9, Airworthiness Limitations (AWLs)
and Certification Maintenance Requirements (CMRs), D622W001-9, dated
August 2022, of Boeing 777 200/200LR/300/300ER/777F Maintenance
Planning Data (MPD) Document. This service information specifies, among
other airworthiness limitations, 28-AWL-31 and 28-AWL-32 that address
cushion clamps and Teflon sleeving installed on out-of-tank wire
bundles installed on brackets that are mounted directly on the fuel
tanks. 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 ADDRESSES.
Costs of Compliance
The FAA estimates that this AD affects 282 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs *
----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action Labor cost Parts cost Cost per product operators
----------------------------------------------------------------------------------------------------------------
Installations, cap sealing, and Up to 545 work- Up to $3,510...... Up to $49,835..... Up to $14,053,470.
inspections. hours x $85 per
hour = $46,325.
----------------------------------------------------------------------------------------------------------------
* Table does not include estimated costs for revising the existing maintenance or inspection program.
The FAA has determined that revising the existing maintenance or
inspection program takes an average of 90 work-hours per operator,
although the agency recognizes that this number may vary from operator
to operator. Since operators incorporate maintenance or inspection
program changes for their affected fleet(s), the FAA has determined
that a per-operator estimate is more accurate than a per-airplane
estimate. Therefore, the FAA estimates the average total cost per
operator to be $7,650 (90 work-hours x $85 per work-hour).
The FAA estimates the following costs to do any necessary
corrective actions that would be required based on the results of the
inspections. The agency has no way of determining the number of
aircraft that might need these actions:
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Action Labor cost Parts cost Cost per product
----------------------------------------------------------------------------------------------------------------
Corrective actions................. Up to 26 work-hours x $85 Up to $3,510.......... Up to $5,720.
per hour = $2,210.
----------------------------------------------------------------------------------------------------------------
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.
The FAA is 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) Will not affect intrastate aviation in Alaska, and
(3) 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.
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:
2023-03-04 The Boeing Company: Amendment 39-22329; Docket No.
[[Page 12556]]
FAA-2022-0810; Project Identifier AD-2021-01238-T.
(a) Effective Date
This airworthiness directive (AD) is effective April 4, 2023.
(b) Affected ADs
(1) This AD affects AD 2017-11-14, Amendment 39-18913 (82 FR
25954, June 6, 2017) (AD 2017-11-14).
(2) This AD also affects AD 2021-24-12, Amendment 39-21833 (86
FR 73660, December 28, 2021) (AD 2021-24-12).
(c) Applicability
This AD applies to all The Boeing Company Model 777-200, -200LR,
-300, -300ER, and 777F series airplanes, certificated in any
category.
(d) Subject
Air Transport Association (ATA) of America Code 57, Wings.
(e) Unsafe Condition
This AD was prompted by fuel system reviews conducted by the
manufacturer. The FAA is issuing this AD to prevent arcing inside
the main and center fuel tanks in the event of a fault current or
lightning strike, which, in combination with flammable fuel vapors,
could result in a fuel tank explosion and consequent loss of the
airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions for Certain Airplanes
For airplanes identified in Boeing Alert Service Bulletin 777-
57A0050, Revision 6, dated August 18, 2021: Except as specified in
paragraph (h) of this AD, at the applicable times specified in
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin
777-57A0050, Revision 6, dated August 18, 2021, do all applicable
actions (i.e., installation of Teflon sleeves, cap sealing of
fasteners, detailed inspections, and corrective actions) identified
in, and in accordance with, the Accomplishment Instructions of
Boeing Alert Service Bulletin 777-57A0050, Revision 6, dated August
18, 2021.
(h) Exceptions to Service Information Specifications
(1) Where Boeing Alert Service Bulletin 777-57A0050, Revision 6,
dated August 18, 2021, uses the phrase ``the revision 5 date of this
service bulletin'' or ``the revision 6 date of this service
bulletin,'' this AD requires using ``the effective date of this
AD.''
(2) Where circle symbol 1 of sheet 2 of Figures 172, 173, and
174 of Boeing Alert Service Bulletin 777-57A0050, Revision 6, dated
August 18, 2021, points to the outboard side of rib no. 9 for the
locate and cap seal task or the inspection task, as applicable, in
step 1 of sheet 3, for this AD, circle symbol 1 points to the seven
fasteners located at the inboard side of rib no. 9 (adjacent to the
right side of the identified seven fasteners).
(3) Where circle symbol 1, next to the text ``7 locations,'' of
sheet 2 of Figure 175 and Figure 176 of Boeing Alert Service
Bulletin 777-57A0050, Revision 6, dated August 18, 2021, points to
the outboard side of rib no. 9 for the locate and cap seal task or
the inspection task, as applicable, in step 1 of sheet 3, for this
AD, circle symbol 1, next to the text ``7 locations,'' points to the
seven fasteners located at the inboard side of rib no. 9 (adjacent
to the right side of the identified seven fasteners).
(4) Where circle symbol 1, next to the text ``7 locations,'' of
sheet 4 of Figure 179 and Figure 180 of Boeing Alert Service
Bulletin 777-57A0050, Revision 6, dated August 18, 2021, points to
the outboard side of rib no. 9 for the locate and cap seal task or
the inspection task, as applicable, in step 1 of sheet 6, for this
AD, circle symbol 1, next to the text ``7 locations,'' points to the
seven fasteners located at the inboard side of rib no. 9 (adjacent
to the left side of the identified seven fasteners).
(5) Where Boeing Alert Service Bulletin 777-57A0050, Revision 6,
dated August 18, 2021, specifies Work Package 28 is applicable to
Group 1 through 4, and Group 8, this AD does not require
accomplishment of Work Package 28 for Group 1 through 4 only.
(6) For Group 1 through 4 airplanes identified in Boeing Alert
Service Bulletin 777-57A0050, Revision 6, dated August 18, 2021, on
which the actions specified in Work Package 37 of Boeing Alert
Service Bulletin 777-57A0050, Revision 6, dated August 18, 2021,
have been accomplished, the actions specified in Work Package 38 are
not required.
(7) Where the Accomplishment Instructions of Boeing Alert
Service Bulletin 777-57A0050, Revision 6, dated August 18, 2021,
specifies to purge specific fuel tanks (right, left, or center),
operators must purge the applicable fuel tank for which access
inside the fuel tank is needed to apply cap sealing to the affected
fasteners.
(i) Maintenance or Inspection Program Revision
Within 60 days after the effective date of this AD, revise the
existing maintenance or inspection program, as applicable, to
incorporate the information for 28-AWL-31 and 28-AWL-32 specified in
Section D, ``Airworthiness Limitations-Systems,'' including
Subsections D.1, of Section 9, Airworthiness Limitations (AWLs) and
Certification Maintenance Requirements (CMRs), D622W001-9, dated
August 2022, of Boeing 777-200/200LR/300/300ER/777F Maintenance
Planning Data (MPD) Document. The initial compliance time for doing
airworthiness limitation instructions (ALI) task 28-AWL-32 is at the
applicable time specified in paragraph (i)(1) or (2) of this AD:
(1) For airplanes having line number (L/Ns) 1 through 503
inclusive: Within 3,750 days after accomplishment of the actions
specified in Boeing Service Bulletin 777-57A0050; within 60 months
after the effective date of this AD; or within 3,750 days after the
most recent inspection was performed as specified in AWL No. 28-AWL-
32; whichever is latest.
(2) For airplanes having L/Ns 504 and subsequent: Within 3,750
days after the date of issuance of the original airworthiness
certificate or the date of issuance of the original export
certificate of airworthiness; within 60 months after the effective
date of this AD; or within 3,750 days after the most recent
inspection was performed as specified in AWL No. 28-AWL-32;
whichever is latest.
(j) Credit for Previous Actions
This paragraph provides credit for the maintenance or inspection
program revision specified in paragraph (i) of this AD, if the
revision was performed before the effective date of this AD using
Section 9, Airworthiness Limitations (AWLs) and Certification
Maintenance Requirements (CMRs), D622W001-9, dated March 2022, dated
June 2022, or dated July 2022, of Boeing 777 200/200LR/300/300ER/
777F Maintenance Planning Data (MPD) Document; provided that the
corrections specified in paragraphs (j)(1) through (4) of this AD
were also incorporated. The following exceptions apply to 28-AWL-31
and 28-AWL-32 of Section D, ``Airworthiness Limitations--Systems,''
including Subsections D.1 of Section 9, Airworthiness Limitations
(AWLs) and Certification Maintenance Requirements (CMRs), D622W001-
9, of Boeing 777-200/200LR/300/300ER/777F Maintenance Planning Data
(MPD) Document.
(1) In paragraph 1.i., change ``Front Spar Bulkhead (Center
Tank)'' to ``Front Spar Bulkhead (Center Wing Tank Fuel Quantity
Greater than 12,400 Gallons).''
(2) In paragraph 1.i.II, change ``For 777-200, 777-200LR, 777-
300, and 777-300ER airplanes, L/N 562 and on'' to ``L/N 562 and on,
except 777F.''
(3) In paragraph 1.i.III., change ``For 777F airplanes, L/N 718
and on'' to ``For 777F airplanes.''
(4) In paragraph 1.j., change ``Rear Spar Bulkhead (Center
Tank)'' to ``Rear Spar Bulkhead (Center Wing Tank Fuel Quantity
Greater than 12,400 Gallons).''
(k) No Alternative Actions, Intervals, or Critical Design Configuration
Control Limitations (CDCCLs)
After the existing maintenance or inspection program has been
revised as required by paragraph (i) of this AD, no alternative
actions (e.g., inspections), intervals, or CDCCLs may be used unless
the actions, intervals, and CDCCLs are approved as an alternative
method of compliance (AMOC) in accordance with the procedures
specified in paragraph (m) of this AD.
(l) Terminating Action for Certain Requirements of AD 2017-11-14 and AD
2021-24-12
(1) Accomplishment of the actions required by paragraph (g) of
this AD terminates the requirements of paragraphs (g)(1), (i), and
(j) of AD 2017-11-14.
(2) Accomplishment of the revision required by paragraph (i) of
this AD terminates the requirements of paragraphs (g)(6) and (h) of
AD 2021-24-12.
(m) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Seattle ACO Branch, FAA, has the authority to
approve AMOCs for this AD, if requested using the procedures
[[Page 12557]]
found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your
request to your principal inspector or responsible Flight Standards
Office, as appropriate. If sending information directly to the
manager of the certification office, send it to the attention of the
person identified in paragraph (n) of this AD. Information may be
emailed to: <a href="/cdn-cgi/l/email-protection#784155393635552b1d190c0c141d55393b37553935373b552a1d090d1d0b0c0b381e1919561f170e"><span class="__cf_email__" data-cfemail="675e4a26292a4a34020613130b024a2624284a262a28244a35021612021413142701060649000811">[email protected]</span></a>.
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the responsible Flight Standards Office.
(3) An AMOC that provides an acceptable level of safety may be
used for any repair, modification, or alteration required by this AD
if it is approved by The Boeing Company Organization Designation
Authorization (ODA) that has been authorized by the Manager, Seattle
ACO Branch, FAA, to make those findings. To be approved, the repair
method, modification deviation, or alteration deviation must meet
the certification basis of the airplane, and the approval must
specifically refer to this AD.
(n) Related Information
For more information about this AD, contact Kevin Nguyen,
Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch,
2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-
3555; email: <a href="/cdn-cgi/l/email-protection#b3d8d6c5dadd9dddd4c6cad6ddf3d5d2d29dd4dcc5"><span class="__cf_email__" data-cfemail="d9b2bcafb0b7f7b7beaca0bcb799bfb8b8f7beb6af">[email protected]</span></a>.
(o) 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 Alert Service Bulletin 777-57A0050, Revision 6, dated
August 18, 2021.
(ii) Section 9, Airworthiness Limitations (AWLs) and
Certification Maintenance Requirements (CMRs), D622W001-9, dated
August 2022, of Boeing 777 200/200LR/300/300ER/777F Maintenance
Planning Data (MPD) Document.
(3) For service information identified in this AD, contact
Boeing Commercial Airplanes, Attention: Contractual & Data Services
(C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-
5600; telephone 562-797-1717; website <a href="http://myboeingfleet.com">myboeingfleet.com</a>.
(4) You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 2200
South 216th St., Des Moines, WA. For information on the availability
of this material at the FAA, call 206-231-3195.
(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, <a href="/cdn-cgi/l/email-protection#5137237f383f2221343225383e3f113f3023307f363e27"><span class="__cf_email__" data-cfemail="80e6f2aee9eef3f0e5e3f4e9efeec0eee1f2e1aee7eff6">[email protected]</span></a>, or go to: <a href="http://www.archives.gov/federal-register/cfr/ibr-locations.html">www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
Issued on February 2, 2023.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2023-04024 Filed 2-27-23; 8:45 am]
BILLING CODE 4910-13-P
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This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.