Rule2026-19751
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
September 28, 2026
Effective
November 2, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes. This AD was prompted by a report of an overheated alternating current motor pump (ACMP) that caused a fire in the main landing gear (MLG) wheel well. This AD requires a records check or inspection for any installed ACMP with a certain part number and applicable on-condition actions. This AD also prohibits the installation of affected parts. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
<html>
<head>
<title>Federal Register, Volume 91 Issue 186 (Monday, September 28, 2026)</title>
</head>
<body><pre>
[Federal Register Volume 91, Number 186 (Monday, September 28, 2026)]
[Rules and Regulations]
[Pages 61127-61133]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-19751]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-3997; Project Identifier AD-2025-01471-T;
Amendment 39-23471; AD 2026-19-04]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all
The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series
airplanes. This AD was prompted by a report of an overheated
alternating current motor pump (ACMP) that caused a fire in the main
landing gear (MLG) wheel well. This AD requires a records check or
inspection for any installed ACMP with a certain part number and
applicable on-condition actions. This AD also prohibits the
installation of affected parts. The FAA is issuing this AD to address
the unsafe condition on these products.
DATES: This AD is effective November 2, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of November 2,
2026.
[[Page 61128]]
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-3997; 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 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-2025-3997.
FOR FURTHER INFORMATION CONTACT: Joshua Baek, Aviation Safety Engineer,
FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 562-627-6725;
email: <a href="/cdn-cgi/l/email-protection#ff95908c978a9ed186d19d9e9a94bf999e9ed1989089"><span class="__cf_email__" data-cfemail="4d27223e25382c6334632f2c28260d2b2c2c632a223b">[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 777-200, -200LR, -300, -300ER, and 777F series airplanes. The
NPRM was published in the Federal Register on November 17, 2025 (90 FR
51216). The NPRM was prompted by a report from an operator of a fire in
the MLG wheel well on a Model 777 airplane. A subsequent investigation
found that the cause of the fire was an overheated ACMP. Further
investigation found that a lock washer and nut were missing from a
moving contact in the related electrical load control unit (ELCU). The
missing lock washer and nut left the main contact operator bar
unrestrained and in a position that let two-phase power go to the ACMP,
which caused the ACMP to overheat, leak hydraulic fluid, and
subsequently start a fire in the MLG wheel well. As a result, the
design of the ACMP has been modified to include fusible links as a new
feature to prevent the ACMP overheat if one of the electrical phases
fails. Additionally, the manufacturer has determined that part number
(P/N) 731966 on continuous two-phase power application may cause the
pump to overheat and ignite a fire in the wheel well. P/N 731966 can be
subjected to a single failure of the ELCU that results in continuous
two-phase power application with no ability to remove power. In the
NPRM, the FAA proposed to require a records check or inspection for any
installed ACMP with a certain part number and applicable on-condition
actions. The FAA is issuing this AD to address a single failure of the
ELCU in the ACMP. This condition, if not addressed, could result in the
ACMP overheating and igniting a fire in the wheel well and consequent
damage to the airplane, loss of continued safe flight and landing and/
or personnel injury.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from Boeing and the Air Line Pilots
Association, International (ALPA) who supported the NPRM without
change.
The FAA also received comments from Air Canada, American Airlines
(American), FedEx, the Citizens Rulemaking Alliance, and United
Airlines (United). The following presents those comments and the FAA's
response.
Request To Delay Issuance of the AD
United requested that the FAA either delay issuance of the proposed
AD until related ADs for the Boeing Model 757 and Model 767 airplanes
are ready for publication or assist Boeing with expediting the release
of the applicable service bulletins for those airplane models, which
United said were scheduled to be released in the second quarter of
2026. United stated it operates Boeing Model 757, 767, and 777
airplanes that all utilize ACMP P/N 731966, and that the new ACMP P/N
3033115-100 is currently applicable only to the Model 767 and Model 777
airplanes, while the Model 757 airplanes are limited to ACMP P/N
731966. United Airlines stated this could create an internal compliance
challenge due to the inability to fully transition away from ACMP P/N
731966 since that part is required for the Model 757 airplanes.
The FAA acknowledges the commenter's concern but disagrees with the
request. The FAA has determined that it is necessary to prohibit
installation of any affected part on any Model 777 airplane as of the
effective date of this AD, and that delaying issuance of this AD would
allow affected parts installed on affected airplanes before the
effective date of this AD to remain on those airplanes longer, which
could affect the safety of the affected fleet. Further, the FAA does
not consider it appropriate to delay issuance while awaiting new
service information for other airplane models that are not applicable
to this AD. However, Boeing recently released the service bulletins for
the Model 757 and Model 767, including the Model 747, airplanes in
March 2026 allowing operators to bring their entire fleet into
compliance. The FAA may issue additional rulemaking mandating these
service bulletins. The FAA did not change this AD as a result of this
comment.
Request To Add Grace Period for Part Installation Prohibition
American requested that the FAA revise paragraph (i) of the
proposed AD to include a 6-month grace period before the parts
installation prohibition becomes effective. American stated that a 6-
month grace period, representing approximately 10 percent of the total
compliance time, would allow operators to obtain sufficient inventory
of upgraded ACMPs to support airplane operational requirements and
reduce the risk of part shortages in the event of in-service failures.
American also noted that Boeing Fleet Team Digest (FTD) 777 FTD-29-
21001, referenced in Boeing Alert Service Bulletin 777-29A0047, dated
September 11, 2025, incorporates steps into the aircraft maintenance
manual requiring an ELCU installation test at all locations where an
ELCU is removed or installed, which would validate the integrity and
safe operation of the ELCU providing power to ACMP P/N 731966.
The FAA acknowledges American's concern but disagrees with the
request. ACMP P/N 731966 can be modified to the new acceptable ACMP
configuration in accordance with the Eaton Aerospace service
information referenced in Boeing Alert Requirements Bulletin 777-
29A0047 RB, dated September 11, 2025. Therefore, the FAA has determined
that sufficient parts should be available to support compliance with
the requirements of this AD. In addition, including a grace period
increases the possibility that an affected part could be installed on
an airplane after the effective date of this AD. The FAA did not change
this AD as a result of this comment.
Request To Use an Alternative Part Number
FedEx requested that the FAA revise paragraph (h)(2) of the
proposed AD to include ACMP P/N 66133-04 as an
[[Page 61129]]
acceptable replacement part for P/N 3033115-100. FedEx stated that the
Boeing 777 illustrated parts catalog (IPC) identifies multiple ACMP
part numbers as eligible for installation, including P/N 66133-04,
which is an earlier version of P/N 66133-06. FedEx noted P/N 66133-04
has been installed on several of its affected airplanes because the IPC
shows it is an eligible alternative.
The FAA disagrees with the request. Although ACMP P/N 66133-04 is
not subject to the identified unsafe condition, the FAA has determined
that installation of that part is not acceptable for compliance with
this AD. In a separate investigation that was not determined to be a
safety issue, P/N 66133-04 was found not to comply with certain
certification requirements. P/N 66133-06 is the redesigned ACMP that
complies with those certification requirements. Boeing has informed the
FAA that references to the interchangeability of P/N 3033115-100 with
P/N 66133-04 will be removed from future revisions of the IPC. Although
the FAA has not mandated the removal of, or prohibited the installation
of, P/N 66133-04, it is not appropriate to specify that part as an
acceptable replacement for compliance with this AD. The FAA did not
change this AD as a result of this comment.
Request To Revise the Applicability of the Parts Installation
Prohibition
FedEx requested that the FAA revise paragraph (i) of the proposed
AD to state that ACMP P/N 731966 may not be installed on any ``Boeing
Model 777 series'' airplane, instead of ``any airplane.'' FedEx stated
the phrase ``on any airplane'' could be interpreted as prohibiting the
installation of P/N 731966 on all airplane models. FedEx noted there
are currently 433 ACMPs having P/N 731966 installed on its fleet of
Boeing Model 757 and Model 767 airplanes, and it does not have
sufficient spare P/N 3033115-100 or approved alternatives available for
replacement on those airplanes.
The FAA disagrees with the request. No change is necessary because
the requirements of this AD, including the parts prohibition in
paragraph (i), apply only to the airplanes identified in paragraph (c)
of this AD.
Request To Clarify Compliance Time for the Parts Installation
Prohibition
Air Canada requested clarification as to whether paragraph (i) of
the proposed AD would require replacement of an already installed ACMP
having P/N 731966 as of the effective date of the AD, or whether the
prohibition would apply only to new installations occurring after the
effective date. As an example, the commenter asked whether a
serviceable P/N 731966 may be installed on an airplane if there is a
maintenance emergency that requires replacement of an ACMP after the AD
is effective but before the 60-month compliance time required by the
AD.
The FAA provides the following response. If an ACMP having P/N
731966 has been installed on an airplane identified in paragraph (c) of
this AD before the effective date of this AD, it must be replaced
within 60 months after the effective date of this AD. However, any ACMP
installed on any airplane after the effective date of this AD must be
an acceptable part number. In the commenter's example, a serviceable P/
N 731966 may not be installed on the airplane.
Request To Justify Forgoing Notice and Comment or Issue an NPRM
The Citizens Rulemaking Alliance requested that the FAA either
provide its justification for finding good cause to bypass notice and
comment procedures, or convert this action to an NPRM with a 30- to 60-
day comment and delay the effective date for airplanes not at immediate
risk. The commenter asserted the FAA has not adequately justified use
of the good cause exemption to bypass notice and comment and the 30-day
delayed effective date.
The FAA notes the comment was submitted in response to an NPRM for
which the FAA provided a 45-day comment period. This final rule is
effective 35 days after its publication in the Federal Register.
Therefore, no change to this AD is necessary.
Request To Make Incorporation by Reference (IBR) Materials Reasonably
Available
The Citizens Rulemaking Alliance requested that the FAA make IBR
material available and free to the public during the comment period and
add the IBR materials to the AD docket.
In the preamble of the NPRM, the FAA notified the public that the
IBR material would be available for review under Docket No. FAA-2025-
3997 at <a href="http://regulations.gov">regulations.gov</a>. This material was posted to the AD docket on
November 17, 2025. Therefore, no change to this AD is necessary.
Request To Comply With the Paperwork Reduction Act (PRA)
The Citizens Rulemaking Alliance requested that the FAA revise the
AD to confirm that the AD complies with the PRA. If the AD does not
comply with the PRA, the commenter requested that the FAA remove or
stay any reporting requirements until the AD complies with the PRA.
The FAA notes this AD does not require reporting. If an AD were to
require reporting, the preamble of the AD would include a paragraph
titled ``Paperwork Reduction Act'' that would provide the applicable
OMB control number, required PRA statements, and the estimated time to
collect the required information (burden). Any costs associated with
the reporting requirement would be included in the Costs of Compliance
section in the preamble of the AD. Therefore, the FAA did not change
this AD as a result of this comment.
Request To Consider Impact on Small Entities
The Citizens Rulemaking Alliance requested that the FAA either
prepare an initial regulatory flexibility analysis, or provide the
factual basis for its conclusion that the AD will not have a
significant economic impact on a substantial number of small entities.
The FAA has considered the AD's impact on small businesses and
provides the following factual basis for its RFA certification.
The Regulatory Flexibility Act of 1980, Pub. L. 96-354, 94 Stat.
1164 (5 U.S.C. 601-612), as amended by the Small Business Regulatory
Enforcement Fairness Act of 1996 (Pub. L. 104-121, 110 Stat. 857, Mar.
29, 1996) and the Small Business Jobs Act of 2010 (Pub. L. 111-240, 124
Stat. 2504, Sept. 27, 2010), requires Federal agencies to consider the
effects of the regulatory action on small business and other small
entities and to minimize any significant economic impact. The term
``small entities'' comprises small businesses and not-for-profit
organizations that are independently owned and operated and are not
dominant in their fields, and governmental jurisdictions with
populations of less than 50,000.
Need for and Objectives of the Rule
The FAA is adopting a new AD for all The Boeing Company Model 777-
200, -200LR, -300, -300ER, and 777F series airplanes. This AD was
prompted by a report of an overheated ACMP that caused a fire in the
MLG wheel well. This AD requires a records check or inspection for any
installed ACMP with a certain part number and applicable on-condition
actions. This AD also prohibits the installation of affected parts. The
FAA is issuing this AD to address the unsafe condition on these
products.
[[Page 61130]]
Small Entities to Which the Rule Will Apply
The FAA used the definition of small entities in the RFA for this
analysis. The RFA defines small entities as small businesses, small
governmental jurisdictions, or small organizations. In 5 U.S.C. 601(3),
the RFA defines ``small business'' to have the same meaning as ``small
business concern'' under section 3 of the Small Business Act. The Small
Business Act authorizes the Small Business Administration (SBA) to
define ``small business'' by issuing regulations.
The SBA (2023) has established size standards for various types of
economic activities, or industries, under the North American Industry
Classification System (NAICS). These size standards generally define
small businesses based on the number of employees or annual receipts.
The following table shows the SBA size standards for all industries
with at least one (1) impacted entity.\1\ Note that the SBA definition
of a small business applies to the parent company and all affiliates as
a single entity.
---------------------------------------------------------------------------
\1\ The FAA does not have entity data, or the entity was
identified as a foreign business on 17 of the 290 affected
airplanes. Those airplanes are excluded from this analysis.
Small Business Size Standards *
------------------------------------------------------------------------
NAICS code NAICS description Threshold
------------------------------------------------------------------------
336411................ Aircraft Manufacturing 1,500 employees.
336413................ Other Aircraft Part 1,500 employees.
and Auxiliary
Equipment
Manufacturing.
481111................ Scheduled Passenger 1,500 employees.
Air Transportation.
481112................ Scheduled Freight Air 1,500 employees.
Transportation.
481211................ Nonscheduled Chartered 1,500 employees.
Passenger Air
Transportation.
481219................ Other Nonscheduled Air 1,500 employees.
Transportation.
532411................ Commercial Air, Rail, $40,000,000.
and Water
Transportation
Equipment Rental and
Leasing.
541614................ Process, Physical $20,000,000.
Distribution and
Logistics Consulting
Services.
927110................ Federal Agency........ 50,000 employees.
------------------------------------------------------------------------
* Source: SBA (2023).
To identify small entities, the FAA first identified the primary
NAICS of the entity or parent company, and then used data from
different sources (e.g., company annual reports, Bureau of
Transportation Statistics) to determine whether the entity meets the
applicable size standard. The following table provides a summary of the
results.
Estimated Number of Small Entities
----------------------------------------------------------------------------------------------------------------
Small Percent
NAICS code NAICS description Number of business Effected small
entities entities aircraft entities
----------------------------------------------------------------------------------------------------------------
336411....................... Aircraft Manufacturing....... 1 0 0 0.00
336413....................... Other Aircraft Part and 1 1 34 100.00
Auxiliary Equipment
Manufacturing.
481111....................... Scheduled Passenger Air 5 1 2 20.00
Transportation.
481112....................... Scheduled Freight Air 4 0 0 0.00
Transportation.
481219....................... Other Nonscheduled Air 2 0 0 0.00
Transportation.
532411....................... Commercial Air, Rail, and 7 2 16 28.57
Water Transportation
Equipment Rental and Leasing.
541614....................... Process, Physical 1 1 1 100.00
Distribution and Logistics
Consulting Services.
927110....................... Federal Agency............... 1 0 0 0.00
----------------------------------------------------------------------------------------------------------------
Projected Reporting, Recordkeeping, and Other Compliance Requirements
The FAA estimates affected entities will incur an inspection cost
of $170 per airplane. Based upon the results of the inspection,
operators could incur replacement costs of $77,099. If an operator were
to incur all inspection and replacement costs, the FAA estimates each
operator would incur $77,269 per airplane. The FAA analyzes the cost of
inspection costs as the low case for each small entity. The high case
includes both inspection and replacement costs for each small entity.
The following table displays the small entity case burdens percentage
for compliance based on annual revenue for each operator and their
associated NAICS industry.
Number of Small Entities Affected by Industry and Cost Significance *
----------------------------------------------------------------------------------------------------------------
Number of
NAICS code ** Description affected small Number of Annual Low cost High cost
entities aircraft revenue (%) (%)
----------------------------------------------------------------------------------------------------------------
336413............... Other Aircraft Part 1 34 $56,000,000 0.01 4.69
and Auxiliary
Equipment
Manufacturing.
481111............... Scheduled Passenger 1 2 7,470,000 0.00 2.07
Air Transportation.
532411............... Commercial Air, Rail, 1 1 26,040,000 0.00 0.30
and Water
Transportation
Equipment Rental and
Leasing.
532411............... Commercial Air, Rail, 1 15 12,200,000 0.02 9.50
and Water
Transportation
Equipment Rental and
Leasing.
[[Page 61131]]
541614............... Process, Physical 1 1 4,800,000 0.00 1.61
Distribution and
Logistics Consulting
Services.
----------------------------------------------------------------------------------------------------------------
* Sources: SBA (2023); Dun & Bradstreet. D&B Hoovers. Retrieved April 28, 2024. <a href="http://app.hoovers.dnb.com">app.hoovers.dnb.com</a>.; ZoomInfo.
ZoomInfo Technologie Inc. Retrieved April 28, 2024. <a href="http://zoominfo.com">zoominfo.com</a>.
** Note: NAICS codes with only one entity would be the number of aircraft. Average aircraft affected are
rounded.
Significant Alternatives Considered
The FAA is adopting a new AD for all The Boeing Company Model 777-
200, -200LR, -300, -300ER, and 777F series airplanes. This AD was
prompted by a report of an overheated ACMP that caused a fire in the
MLG wheel well. This AD requires a records check or inspection for any
installed ACMP with a certain part number and applicable on-condition
actions. This AD also prohibits the installation of affected parts. No
alternatives were considered as the FAA is issuing this AD to address
the unsafe condition on these products.
Request To Provide Additional Cost Information
The Citizens Rulemaking Alliance requested that the FAA add to the
docket the economic analysis underlying the FAA's determination that
the AD is not significant under Executive Order 12866 and not
applicable to the Unfunded Mandates Reform Act. The commenter stated
the cost analysis should include the number of affected U.S.-registered
airplanes, labor hour assumptions, parts costs, expected airplane
downtime, and aggregate costs.
In the Costs of Compliance section of the proposed AD, the FAA
disclosed the number of affected airplanes on the U.S. registry,
estimated number of work hours and parts costs provided by the
manufacturer, and the aggregate costs. Additionally, the FAA considered
the impact that this AD will have on affected operators and determined
this AD will not trigger any downtime costs because the requirements of
this AD can be performed during regularly scheduled maintenance.
Further, the FAA has determined that the current labor rate of $85
per hour remains accurate for this AD. The FAA evaluates this rate
periodically, based on U.S. Department of Labor Statistic (BLS) data
found at <a href="https://data.bls.gov/oes">https://data.bls.gov/oes</a>, and will change the rate when
appropriate. The FAA used a blended wage rate to estimate the labor
rate for this AD, where the FAA assumes 60 percent weight for aircraft
mechanics (at a fully burdened mean wage rate of $69.85 per hour) and
40 percent for general and operations managers (at a fully burdened
mean wage rate of $108.15 per hour). To calculate the blended wage
rate, the FAA multiplied each wage rate by its corresponding weight and
added up the products to obtain a wage rate of $85.17, which the FAA
rounded down to $85.
Since the FAA has assessed and disclosed all known costs of the AD
requirements in the Costs of Compliance section of the proposed AD, and
the commenter did not provide additional cost data for the FAA to
consider in its cost analysis, the FAA determined that the existing
analysis is complete. Based upon the analysis provided throughout the
proposed AD and in the previous comment response, the FAA certifies
that this AD is not a ``significant regulatory action'' under Executive
Order 12866. The FAA did not change this AD as a result of this
comment.
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.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Boeing Alert Requirements Bulletin 777-29A0047 RB,
dated September 11, 2025. This material specifies procedures for a
records check or inspection for any installed ACMP with P/N 731966 and
applicable on-condition actions. On-condition actions include replacing
any ACMP P/N 731966 with ACMP P/N 3033115-100 or later approved ACMP
part number at affected locations. 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.
Costs of Compliance
The FAA estimates that this AD affects 334 airplanes of U.S.
registry, and that the inspection/records review is required for 290 of
those airplanes. The FAA estimates the following costs to comply with
this AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
----------------------------------------------------------------------------------------------------------------
Inspection/Records review.......... 2 work-hours x $85 per hour $0 $170 $49,300
= $170.
----------------------------------------------------------------------------------------------------------------
The FAA estimates the following costs to do any necessary
replacements that would be required based on the results of the
inspection. The agency has no way of determining the number of aircraft
that might need this replacement:
[[Page 61132]]
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Action Labor cost Parts cost Cost per product
----------------------------------------------------------------------------------------------------------------
Replacement..................... 5 work-hours x $85 per hour Up to $76,674.......... Up to $77,099.
= $425.
----------------------------------------------------------------------------------------------------------------
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, and
(2) Will not affect intrastate aviation in Alaska.
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:
2026-19-04 The Boeing Company: Amendment 39-23471; Docket No. FAA-
2025-3997; Project Identifier AD-2025-01471-T.
(a) Effective Date
This airworthiness directive (AD) is effective November 2, 2026.
(b) Affected ADs
None.
(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 29, Hydraulic
Power.
(e) Unsafe Condition
This AD was prompted by a report of an overheated alternating
current motor pump (ACMP) that caused a fire in the main landing
gear (MLG) wheel well. A subsequent investigation found that the
cause of the fire was an overheated ACMP. Further investigation
found that a lock washer and nut were missing from a moving contact
in the related electrical load control unit (ELCU). The FAA is
issuing this AD to address a single failure of the ELCU in the ACMP.
The unsafe condition, if not addressed, could result in the ACMP
overheating and igniting a fire in the wheel well and consequent
damage to the airplane, loss of continued safe flight and landing
and/or personnel injury.
(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 777-29A0047 RB, dated September 11,
2025, do all applicable actions identified in, and in accordance
with, the Accomplishment Instructions of Boeing Alert Requirements
Bulletin 777-29A0047 RB, dated September 11, 2025.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
777-29A0047, dated September 11, 2025, which is referred to in
Boeing Alert Requirements Bulletin 777-29A0047 RB, dated September
11, 2025.
(h) Exceptions to Requirements Bulletin Specifications
(1) Where the Compliance Time column of the table in the
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 777-
29A0047 RB, dated September 11, 2025, refer to the original issue
date of Requirements Bulletin 777-29A0047 RB, this AD requires using
the effective date of this AD.
(2) Where Boeing Alert Requirements Bulletin 777-29A0047 RB,
dated September 11, 2025, refers to part number 3033115-100 as a
replacement part, for this AD, part numbers 66133-06 or 66068-08 are
also acceptable replacement parts.
(i) Parts Installation Prohibition
As of the effective date of this AD, no person may install any
ACMP, having part number 731966, on any airplane.
(j) 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 Continued Operational
Safety Branch, send it to the attention of the person identified in
paragraph (k)(1) of this AD. Information may be emailed to:
<a href="/cdn-cgi/l/email-protection#eaaba7a5a9aa8c8b8bc48d859c"><span class="__cf_email__" data-cfemail="1a5b5755595a7c7b7b347d756c">[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.
(k) Additional Information
(1) For more information about this AD, contact Joshua Baek,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; phone: 562-627-6725; email: <a href="/cdn-cgi/l/email-protection#03696c706b76622d7a2d61626668436562622d646c75"><span class="__cf_email__" data-cfemail="0c66637f64796d2275226e6d69674c6a6d6d226b637a">[email protected]</span></a>.
[[Page 61133]]
(2) Material identified in this AD that is not incorporated by
reference is available at the address specified in paragraph (l)(3)
this AD.
(l) 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 777-29A0047 RB, dated
September 11, 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#573125793e3924273234233e3839173936253679303821"><span class="__cf_email__" data-cfemail="3c5a4e1255524f4c595f485553527c525d4e5d125b534a">[email protected]</span></a>.
Issued on September 16, 2026.
Brian Knaup,
Acting Deputy Director, Integrated Certificate Management Division,
Aircraft Certification Service.
[FR Doc. 2026-19751 Filed 9-25-26; 8:45 am]
BILLING CODE 4910-13-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on September 28, 2026.
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.