Rule2023-04848
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
March 10, 2023
Effective
April 14, 2023
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is superseding Airworthiness Directive (AD) 2021-07- 09, which applies to all The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes. AD 2021-07-09 required repetitively inspecting all trim air diffuser ducts or sidewall riser duct assemblies (collectively referred to as TADDs) for damage, including repetitive structural inspections of the center fuel tanks for damage, and performing applicable on-condition actions. Since the FAA issued AD 2021-07-09, the agency has determined that the existing requirements do not adequately address the unsafe condition. This AD continues to require repetitive inspections of the TADDs for damage, with revised compliance times, and repair if applicable. This AD also requires repetitive replacement of the TADDs and removes the structural inspections of the center fuel tanks. This AD also prohibits the installation of affected parts. This AD removes certain airplanes from the applicability. 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 47 (Friday, March 10, 2023)</title>
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[Federal Register Volume 88, Number 47 (Friday, March 10, 2023)]
[Rules and Regulations]
[Pages 14874-14877]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-04848]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2022-1058; Project Identifier AD-2022-00256-T;
Amendment 39-22340; AD 2023-03-15]
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 superseding Airworthiness Directive (AD) 2021-07-
09, which applies to all The Boeing Company Model 747-100, 747-100B,
747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D,
747-400F, 747SR, and 747SP series airplanes. AD 2021-07-09 required
repetitively inspecting all trim air diffuser ducts or sidewall riser
duct assemblies (collectively referred to as TADDs) for damage,
including repetitive structural inspections of the center fuel tanks
for damage, and performing applicable on-condition actions. Since the
FAA issued AD 2021-07-09, the agency has determined that the existing
requirements do not adequately address the unsafe condition. This AD
continues to require repetitive inspections of the TADDs for damage,
with revised compliance times, and repair if applicable. This AD also
requires repetitive replacement of the TADDs and removes the structural
inspections of the center fuel tanks. This AD also prohibits the
installation of affected parts. This AD removes certain airplanes from
the applicability. The FAA is issuing this AD to address the unsafe
condition on these products.
DATES: This AD is effective April 14, 2023.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of April 14,
2023.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2022-1058; 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; internet <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-2022-1058.
FOR FURTHER INFORMATION CONTACT: Nicole S. Tsang, Aerospace Engineer,
Cabin Safety and Environmental Systems Section, FAA, Seattle ACO
Branch, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-
3959; email: <a href="/cdn-cgi/l/email-protection#2947404a46454c075a075d5a48474e694f4848074e465f"><span class="__cf_email__" data-cfemail="0967606a66656c277a277d7a68676e496f6868276e667f">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2021-07-09, Amendment 39-21486 (86 FR
17899, April 7, 2021) (AD 2021-07-09). AD 2021-07-09 applied to all The
Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-
200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP
series airplanes. The NPRM published in the Federal Register on
September 8, 2022 (87 FR 54919). The NPRM was prompted by reports of
sealant deteriorating on the outside of the center wing fuel tank and
analysis showing that sealant may deteriorate inside the tank due to
excess heat from TADDs. The NPRM was also prompted by reports
indicating that the high temperature composite material TADD failed. AD
2021-07-09 requires replacing original fiberglass fabric material with
high temperature composite material TADDs, repetitively inspecting the
TADDs for damage, and
[[Page 14875]]
as applicable inspecting the center wing fuel tank secondary fuel
barrier coating and primary sealant for damage, and repairing damage.
In the NPRM, the FAA proposed to continue to require repetitive
inspections of the TADDs for damage, with revised compliance times, and
repair if applicable. The NPRM also proposed to require repetitive
replacement of the TADDs and remove the structural inspections of the
center fuel tanks. In addition, this AD prohibits the installation of
affected parts. The FAA is issuing this AD to address potential hot air
leakage from original fiberglass fabric material or high temperature
composite material TADD that can cause damage to the center wing fuel
tank secondary fuel barrier coating and primary sealant, which can
cause fuel leakage into an ignition zone, possibly resulting in a fire
or explosion.
For information on the procedures and compliance times, see the
service information at <a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2022-1058.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from four commenters. Commenters included
Air Line Pilots Association, International (ALPA) who supported the
NPRM without change, and an individual whose comment is outside the
scope of this rulemaking. The FAA received additional comments from
Boeing and another commenter. The following presents the comments
received on the NPRM and the FAA's response to each comment.
Request for Clarification on Credit for Previous Actions
A commenter asked if an operator can claim full credit against the
proposed AD if the operator with Group 2 airplanes performed Boeing
Service Bulletin 747-21A2577-00 and conducted the TADD replacement
associated with certain comments from AD 2021-07-09 in order to extend
the inspection interval.
The FAA infers the commenter is referring to the FAA's response to
a comment in AD 2021-07-09. That response states as follows:
After initial installation of high temperature TADDs, operators
may avoid repeat inspections at 1,200 FH intervals by installing new
high temperature TADDs at each 16,000 FH interval, without an
alternative method of compliance (AMOC) or additional rulemaking, as
long as required actions are completed at that interval.
The FAA infers the commenter is requesting the same allowance from
the FAA's response to the comment in AD 2021-07-09 to replace the TADD
in lieu of performing repetitive inspections of the TADD at 1,200-
flight-hour intervals. The FAA provides the following clarifications of
the AD requirements. This AD requires operators to perform repetitive
inspection of the TADD, report any TADD damages to Boeing, and replace
the TADD at 16,000-flight-hour intervals. This AD does not provide an
option for a TADD to continue in service after 16,000 flight hours.
The proposed AD would have required Boeing Alert Requirements
Bulletin 747-21A2577 RB, Revision 1, dated March 9, 2022. This AD has
been revised to require Boeing Alert Requirements Bulletin 747-21A2577
RB, Revision 2, dated February 10, 2023. However, paragraph (j) of this
AD provides credit for actions done before the effective date of the AD
using Boeing Alert Requirements Bulletin 747-21A2577 RB, dated February
18, 2020; or Revision 1, dated March 9, 2022.
Request for Change in Applicability
Boeing requested that the FAA revise paragraph (c),
``Applicability,'' of the proposed AD to remove the following Model 747
Large Cargo Freighters (LCF) airplanes: variable numbers RT631, RT743,
RT876, and RT632. The listed LCF airplanes should not be applicable
because the listed LCF airplanes do not have original fiberglass fabric
material or high temperature composite material TADD.
The FAA agrees with the request for the reasons provided by the
commenter. The FAA notes that paragraph 1.A., ``Effectivity,'' of
Boeing Alert Requirements Bulletin 747-21A2577 RB, Revision 2, dated
February 10, 2023, specifically excludes line numbers 766, 778, 904,
and 932 (variable numbers RT631, RT743, RT876, and RT632). The FAA
revised paragraph (c) of this AD to limit the applicability to
airplanes identified in Boeing Alert Requirements Bulletin 747-21A2577
RB, Revision 2, dated February 10, 2023.
Request for Change to the Service Bulletins Cited
Boeing requested the FAA to reference Revision 2 instead of
Revision 1 of Service Bulletin and Requirements Bulletin 747-21A2577.
Revision 2 of this service information will address the issue of
Appendix A and Appendix B not being in the RB.
The FAA agrees with Boeing's request. As stated previously, the FAA
has revised this AD to require Boeing Alert Requirements Bulletin 747-
21A2577 RB, Revision 2, dated February 10, 2023. Revision 2 added the
missing appendixes and introduces no other changes that affect
compliance.
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.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Boeing Alert Requirements Bulletin 747-21A2577 RB,
Revision 2, dated February 10, 2023. This service information specifies
procedures for repetitive detailed inspections for damage of TADDs made
of original fiberglass fabric material and high temperature composite
material, repetitive replacement of TADDs, and repair of damaged TADDs.
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 104 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
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Retained repetitive inspections Up to 44 work- $0................ Up to $3,740 per Up to $388,960 per
(AD2021-07-09). hours x $85 per inspection cycle. inspection cycle.
hour = up to
$3,740 per
inspection cycle.
[[Page 14876]]
Repetitive TADD replacement..... Up to 49 work- Up to $12,000..... Up to $16,165 per Up to $1,681,160
hours x $85 per inspection cycle. per replacement
hour = $4,165 per cycle.
replacement cycle.
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The FAA has received no definitive data on which to base the cost
estimates for the on-condition repairs specified in this AD.
The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some or all of the costs of
this AD may be covered under warranty, thereby reducing the cost impact
on affected operators.
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:
0
a. Removing Airworthiness Directive (AD) 2021-07-09, Amendment 39-21486
(86 FR 17899, April 7, 2021); and
0
b. Adding the following new AD:
2023-03-15 The Boeing Company: Amendment 39-22340; Docket No. FAA-
2022-1058; Project Identifier AD-2022-00256-T.
(a) Effective Date
This airworthiness directive (AD) is effective April 14, 2023.
(b) Affected ADs
This AD replaces AD 2021-07-09, Amendment 39-21486 (86 FR 17899,
April 7, 2021) (AD 2021-07-09).
(c) Applicability
This AD applies to The Boeing Company Model 747-100, 747-100B,
747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-
400D, 747-400F, 747SR, and 747SP series airplanes, certificated in
any category, as identified in Boeing Alert Requirements Bulletin
747-21A2577 RB, Revision 2, dated February 10, 2023.
(d) Subject
Air Transport Association (ATA) of America Code: 21, Air
conditioning.
(e) Unsafe Condition
This AD was prompted by reports of sealant deteriorating on the
outside of the center wing fuel tank and analysis showing that
sealant could deteriorate inside the fuel tank due to excess heat
from trim air diffuser ducts or sidewall riser duct assemblies
(collectively referred to as TADDs), and by the determination that
existing requirements do not adequately address the unsafe
condition. The FAA is issuing this AD to address potential hot air
leakage from original fiberglass fabric material or high temperature
composite material TADDs that can cause damage to the center wing
fuel tank secondary fuel barrier coating and primary sealant, which
can cause fuel leakage into an ignition zone, possibly resulting in
a fire or explosion.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
Except as specified by paragraph (h) of this AD: At the
applicable times specified in the ``Compliance'' paragraph of Boeing
Alert Requirements Bulletin 747-21A2577 RB, Revision 2, dated
February 10, 2023, do all applicable actions identified in, and in
accordance with, the Accomplishment Instructions of Boeing Alert
Requirements Bulletin 747-21A2577 RB, Revision 2, dated February 10,
2023.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
747-21A2577, Revision 2, dated February 10, 2023, which is referred
to in Boeing Alert Requirements Bulletin 747-21A2577 RB, Revision 2,
dated February 10, 2023.
(h) Exceptions to Service Information Specifications
(1) Where the Compliance Time column of the tables in the
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 747-
21A2577 RB, Revision 2, dated February 10, 2023, uses the phrase
``the Revision 1 date of Requirements Bulletin 747-21A2577 RB,''
this AD requires using ``the effective date of this AD.''
(2) Where Boeing Alert Requirements Bulletin 747-21A2577 RB,
Revision 2, dated February 10, 2023, specifies contacting Boeing for
repair instructions: This AD requires doing the repair before
further flight using a method approved in accordance with the
procedures specified in paragraph (k) of this AD.
(i) Parts Installation Prohibition
As of the effective date of this AD, no person may install an
original fiberglass fabric material TADD assembly, having a part
number listed in Appendix A of Boeing Alert Requirements Bulletin
747-21A2577 RB, Revision 2, dated February 10, 2023, on any
airplane.
(j) 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 the service
[[Page 14877]]
information identified in paragraph (j)(1) or (2) of this AD.
(1) Boeing Alert Requirements Bulletin 747-21A2577 RB, dated
February 18, 2020, which was incorporated by reference in AD 2021-
07-09.
(2) Boeing Alert Requirements Bulletin 747-21A2577 RB, Revision
1, dated March 9, 2022, which is not incorporated by reference in
this AD.
(k) 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 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 (l) of this AD. Information may be emailed
to: <a href="/cdn-cgi/l/email-protection#132a3e525d5e3e40767267677f763e52505c3e525e5c503e4176626676606760537572723d747c65"><span class="__cf_email__" data-cfemail="98a1b5d9d6d5b5cbfdf9ececf4fdb5d9dbd7b5d9d5d7dbb5cafde9edfdebecebd8fef9f9b6fff7ee">[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.
(4) AMOCs approved for AD 2021-07-09 are approved as AMOCs for
the corresponding provisions of Boeing Alert Requirements Bulletin
747-21A2577 RB, Revision 2, dated February 10, 2023, that are
required by paragraph (g) of this AD.
(l) Related Information
For more information about this AD, contact Nicole S. Tsang,
Aerospace Engineer, Cabin Safety and Environmental Systems Section,
FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198;
phone: 206-231-3959; email: <a href="/cdn-cgi/l/email-protection#06686f65696a6328752872756768614660676728616970"><span class="__cf_email__" data-cfemail="bad4d3d9d5d6df94c994cec9dbd4ddfadcdbdb94ddd5cc">[email protected]</span></a>.
(m) 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 Requirements Bulletin 747-21A2577 RB, Revision
2, dated February 10, 2023.
(ii) [Reserved]
(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; internet <a href="http://myboeingfleet.com">myboeingfleet.com</a>. You may
view this referenced 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.
(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, email <a href="/cdn-cgi/l/email-protection#593f2b7730372a293c3a2d3036371937382b38773e362f"><span class="__cf_email__" data-cfemail="086e7a2661667b786d6b7c6167664866697a69266f677e">[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 25, 2023.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2023-04848 Filed 3-9-23; 8:45 am]
BILLING CODE 4910-13-P
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