Rule2026-22317
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
November 2, 2026
Effective
December 7, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is superseding Airworthiness Directive (AD) 2023-07- 09, which applied to certain The Boeing Company Model 747-400 and -8 series airplanes. AD 2023-07-09 required inspecting for wear of the transfer pump housing inlet check valves and transfer pump motor impeller inlet adapters for the horizontal stabilizer fuel tank and doing corrective actions, if necessary, and limited the installation of affected parts. This AD was prompted by the manufacturer developing further action to address the unsafe condition. This AD requires repetitive inspections for damage of the transfer pump housing inlet check valves and transfer pump motor impeller inlet adapters for the horizontal stabilizer fuel tank and applicable on-condition actions. This AD also limits the installation of affected parts under certain conditions. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 91 Issue 210 (Monday, November 2, 2026)</title>
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[Federal Register Volume 91, Number 210 (Monday, November 2, 2026)]
[Rules and Regulations]
[Pages 68879-68882]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-22317]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-7215; Project Identifier AD-2025-01558-T;
Amendment 39-23506; AD 2026-22-04]
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 superseding Airworthiness Directive (AD) 2023-07-
09, which applied to certain The Boeing Company Model 747-400 and -8
series airplanes. AD 2023-07-09 required inspecting for wear of the
transfer pump housing inlet check valves and transfer pump motor
impeller inlet adapters for the horizontal stabilizer fuel tank and
doing corrective actions, if necessary, and limited the installation of
affected parts. This AD was prompted by the manufacturer developing
further action to address the unsafe condition. This AD requires
repetitive inspections for damage of the transfer pump housing inlet
check valves and transfer pump motor impeller inlet adapters for the
horizontal stabilizer fuel tank and applicable on-condition actions.
This AD also limits the installation of affected parts under certain
conditions. The FAA is issuing this AD to address the unsafe condition
on these products.
DATES: This AD is effective December 7, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of December 7,
2026.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-7215; 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
[[Page 68880]]
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 Boeing material 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>.
<bullet> You may view this material 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-2026-7215.
FOR FURTHER INFORMATION CONTACT: Samuel Dorsey, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3415; email: <a href="/cdn-cgi/l/email-protection#6211030f17070e4c084c060d1011071b220403034c050d14"><span class="__cf_email__" data-cfemail="3744565a42525b195d1953584544524e7751565619505841">[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 2023-07-09, Amendment 39-22411 (88 FR
22895, April 14, 2023) (AD 2023-07-09). AD 2023-07-09 applied to
certain Model 747-400 and -8 series airplanes. The NPRM was published
in the Federal Register on July 9, 2026 (91 FR 42387). The NPRM was
prompted by the manufacturer developing further action to address the
unsafe condition. In the NPRM, the FAA proposed to require repetitive
inspections for damage of the transfer pump housing inlet check valves
and transfer pump motor impeller inlet adapters for the horizontal
stabilizer fuel tank and applicable on-condition actions. The NPRM also
proposed to limit the installation of affected parts under certain
conditions. The FAA is issuing this AD to address the development of an
ignition source within the horizontal stabilizer fuel tank resulting
from wear to the transfer pump housing inlet check valves and transfer
pump motor impeller inlet adapters of the horizontal stabilizer fuel
tank. The unsafe condition, if not addressed, could, in combination
with flammable fuel vapors, result in a fuel tank explosion and
consequent loss of the airplane.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from Air Line Pilots Association,
International (ALPA) and Boeing who supported the NPRM without change.
The FAA received an additional comment from Turkish Airlines. The
following presents the comments received on the NPRM and the FAA's
response to each comment.
Request To Revise Applicability
Turkish Airlines requested that the FAA revise paragraph (c) of the
proposed AD to be similar to the applicability of AD 2023-07-09 and to
specify that airplanes equipped with an activated horizontal stabilizer
fuel tank with Crane Aerospace Hydro-Aire horizontal stabilizer fuel
transfer pump housings and transfer pump motor impellers are affected,
instead of referencing Boeing Alert Requirements Bulletin 747-28A2373
RB, dated November 6, 2025 (Boeing Alert Requirements Bulletin 747-
28A2373 RB), for identification information. Turkish Airlines stated
that Boeing Alert Requirements Bulletin 747-28A2373 RB's effectivity
identifies two configurations: (1) Model 747-400 and 747-8 airplanes
equipped with activated horizontal stabilizer fuel tank with Crane
Aerospace Hydro-Aire horizontal stabilizer fuel transfer pump housings
and transfer pump motor impellers; and (2) Model 747-400 and 747-8
airplanes not equipped with an activated horizontal stabilizer fuel
tank with Crane Aerospace Hydro-Aire horizontal stabilizer fuel
transfer pump housings and transfer pump motor impellers. Turkish
Airlines added that no action is required for airplanes in the second
configuration.
The FAA disagrees. Determining whether an airplane was included in
AD 2023-07-09's applicability required an examination of each
airplane's configuration to determine whether the AD applied to that
airplane, regardless of whether the airplane was determined to be
affected by the AD's requirements. Boeing Alert Requirements Bulletin
747-28A2373 RB contains a definitive list of all airplanes that could
be affected by the unsafe condition and requires an examination of
their configuration. While either approach would produce an acceptable
outcome, in this situation, referring to the service information to
determine applicability is clearer and consistent with the principle
that only airplanes to which the AD applies are subject to the
requirements of this AD. No change to this AD has been made in this
regard.
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, this
AD is adopted as proposed in the NPRM. None of the changes will
increase the economic burden on any operator.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Boeing Alert Requirements Bulletin 747-28A2373 RB,
dated November 6, 2025. This material specifies procedures for
repetitive detailed inspections of the transfer pump housing inlet
check valves and transfer pump motor impeller inlet adapters for any
damage and applicable on-condition actions. On-condition actions
include replacing the damaged transfer pump housing inlet check valve
with a new or serviceable transfer pump housing inlet check valve
(Option 1), or replacing the affected transfer pump housing with a
transfer pump housing containing a new or serviceable transfer pump
housing inlet check valve (Option 2); and replacing an affected
transfer pump motor impeller with a new or serviceable transfer pump
motor impeller.
This material 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.
Interim Action
The FAA considers this AD to be an interim action. The main and
center wing tanks utilize the same pump design but are currently not
subject to the same unsafe condition due to the shutoff logic of the
pumps. However, if further analysis or reports related to the main or
center tank pumps change this assessment, the FAA might consider
further rulemaking for those tanks.
Costs of Compliance
The FAA estimates that this AD affects 31 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
[[Page 68881]]
Estimated Costs
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Cost on U.S.
Action Labor cost Parts cost Cost per product operators
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Inspection of transfer pump 18 work-hours x $85 $0 $1,530 per $47,430 per
housing inlet check valve (2 per per hour = $1,530 inspection cycle. inspection cycle.
airplane). per inspection
cycle.
Inspection of transfer pump motor 18 work-hours x $85 0 $1,530 per $47,430 per
impeller inlet adapter (2 per per hour = $1,530 inspection cycle. inspection cycle.
airplane). per inspection
cycle.
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The FAA estimates the following costs to do any necessary
replacements that would be required based on the results of the
proposed inspection. The agency has no way of determining the number of
aircraft that might need these replacements:
On-Condition Costs
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Action Labor cost Parts cost Cost per product
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Replacement of transfer pump motor 2 work-hours x $85 per Up to $2,400........... Up to $2,570.
impeller. hour = $170.
Replacement of transfer pump housing 2 work-hours x $85 per $1,800................. $1,970.
inlet check valve (Option 1). hour = $170.
Replacement of transfer pump housing 2 work-hours x $85 per Up to $20,000.......... Up to $20,170.
(Option 2). hour = $170.
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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) 2023-07-09, Amendment 39-22411
(88 FR 22895, April 14, 2023); and
0
b. Adding the following new AD:
2026-22-04 The Boeing Company: Amendment 39-23506; Docket No. FAA-
2026-7215; Project Identifier AD-2025-01558-T.
(a) Effective Date
This airworthiness directive (AD) is effective December 7, 2026.
(b) Affected ADs
This AD replaces AD 2023-07-09, Amendment 39-22411 (88 FR 22895,
April 14, 2023) (AD 2023-07-09).
(c) Applicability
This AD applies to The Boeing Company Model 747-400 and -8
series airplanes, certificated in any category, as identified in
Boeing Alert Requirements Bulletin 747-28A2373 RB, dated November 6,
2025.
(d) Subject
Air Transport Association (ATA) of America Code 28, Fuel.
(e) Unsafe Condition
This AD was prompted by reports of wear-through of the transfer
pump motor impeller inlet adapter of the horizontal stabilizer fuel
tank transfer pump caused by contact between the transfer pump
housing inlet check valve and the inlet adapter. The FAA is issuing
this AD to address the development of an ignition source within the
horizontal stabilizer fuel tank resulting from wear to the transfer
pump housing inlet check valves and transfer pump motor impeller
inlet adapters of the horizontal stabilizer fuel tank. The unsafe
condition, if not addressed, could, in combination with flammable
fuel vapors, 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
Except as specified by paragraph (h) of this AD: At the
applicable times specified in the ``Compliance'' paragraph of Boeing
Alert Requirements Bulletin 747-28A2373 RB, dated November 6, 2025,
do all applicable
[[Page 68882]]
actions identified in, and in accordance with, the Accomplishment
Instructions of Boeing Alert Requirements Bulletin 747-28A2373 RB,
dated November 6, 2025.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
747-28A2373, dated November 6, 2025, which is referred to in Boeing
Alert Requirements Bulletin 747-28A2373 RB, dated November 6, 2025.
(h) Exceptions to Requirements Bulletin Specifications
Where the Compliance Time column of the tables in the
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 747-
28A2373 RB, dated November 6, 2025, refers to the original issue
date of Requirements Bulletin 747-28A2373 RB, this AD requires using
the effective date of this AD.
(i) Parts Installation Limitation
As of the effective date of this AD, no person may install, on
any airplane, a Crane Aerospace Hydro-Aire horizontal stabilizer
fuel transfer pump housing, transfer pump housing inlet check valve,
or transfer pump motor impeller into the horizontal stabilizer fuel
tank unless the transfer pump housing inlet check valve and transfer
pump motor impeller inlet adapter have been inspected as specified
in paragraph (g) of this AD, as applicable, and been determined to
be a serviceable part as defined in Boeing Alert Requirements
Bulletin 747-28A2373 RB, dated November 6, 2025.
(j) Special Flight Permit
Special flight permits may be issued in accordance with 14 CFR
21.197 and 21.199 to operate the airplane to a location where the
actions required by this AD can be performed, provided the
horizontal stabilizer fuel tank is defueled and both transfer pump
circuit breakers are locked in the ``open'' position.
(k) Alternative Methods of Compliance (AMOCs)
(1) The Manager, AIR-520, Continued Operational Safety 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)(1) of this AD. Information may be emailed to: <a href="/cdn-cgi/l/email-protection#87c6cac8c4c7e1e6e6a9e0e8f1"><span class="__cf_email__" data-cfemail="f5b4b8bab6b5939494db929a83">[email protected]</span></a>.
Before using any approved AMOC, notify your appropriate principal
inspector, or lacking a principal inspector, the manager of the
responsible Flight Standards Office.
(2) 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, AIR-
520, Continued Operational Safety 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.
(l) Additional Information
(1) For more information about this AD, contact Samuel Dorsey,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; phone: 206-231-3415; email: <a href="/cdn-cgi/l/email-protection#087b69657d6d642662266c677a7b6d71486e6969266f677e"><span class="__cf_email__" data-cfemail="90e3f1fde5f5fcbefabef4ffe2e3f5e9d0f6f1f1bef7ffe6">[email protected]</span></a>.
(2) Material identified in this AD that is not incorporated by
reference is available at the address specified in paragraph (m)(3)
of this AD.
(m) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference of the material listed in this paragraph
under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this material as applicable to do the actions
required by this AD, unless the AD specifies otherwise.
(i) Boeing Alert Requirements Bulletin 747-28A2373 RB, dated
November 6, 2025.
(ii) [Reserved]
(3) For Boeing material 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 material 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 material at the National Archives and
Records Administration (NARA). For information on the availability
of this material at NARA, visit <a href="http://www.archives.gov/federal-register/cfr/ibr-locations">www.archives.gov/federal-register/cfr/ibr-locations</a> or email <a href="/cdn-cgi/l/email-protection#2b4d59054245585b4e485f4244456b454a594a054c445d"><span class="__cf_email__" data-cfemail="7d1b0f5314130e0d181e091412133d131c0f1c531a120b">[email protected]</span></a>.
Issued on October 26, 2026.
Brian Knaup,
Acting Deputy Director, Integrated Certificate Management Division,
Aircraft Certification Service.
[FR Doc. 2026-22317 Filed 10-30-26; 8:45 am]
BILLING CODE 4910-13-P
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