Rule2026-10803
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
May 29, 2026
Effective
July 6, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-100, -100B, -100B SUD, -200B, -200C, - 200F, -300, -400, -400D, -400F, 747SP, and 747SR series airplanes. This AD was prompted by reports of corrosion damage found on a certain satellite communications (SATCOM) high gain antenna adapter plate. This AD requires repetitive detailed inspections (DETs) of the SATCOM high gain antenna adapter plate for corrosion and applicable on-condition actions. 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 103 (Friday, May 29, 2026)</title>
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[Federal Register Volume 91, Number 103 (Friday, May 29, 2026)]
[Rules and Regulations]
[Pages 31884-31887]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-10803]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-3422; Project Identifier AD-2025-00763-T;
Amendment 39-23354; AD 2026-10-14]
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 747-100, -100B, -100B SUD, -200B, -200C, -
200F, -300, -400, -400D, -400F, 747SP, and 747SR series airplanes. This
AD was prompted by reports of corrosion damage found on a certain
satellite communications (SATCOM) high gain antenna adapter plate. This
AD requires repetitive detailed inspections (DETs) of the SATCOM high
gain antenna adapter plate for corrosion and applicable on-condition
actions. The FAA is issuing this AD to address the unsafe condition on
these products.
DATES: This AD is effective July 6, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of July 6,
2026.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-3422; 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-2025-3422.
FOR FURTHER INFORMATION CONTACT: Camille Seay, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 817-
222-5149; email: <a href="/cdn-cgi/l/email-protection#c7a4a6aaaeababa2e9abe9b4a2a6be87a1a6a6e9a0a8b1"><span class="__cf_email__" data-cfemail="8cefede1e5e0e0e9a2e0a2ffe9edf5cceaededa2ebe3fa">[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 The Boeing Company
Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -
400D, -400F, 747SP, and 747SR series airplanes. The NPRM was published
in the Federal Register on September 30, 2025 (90 FR 46771). The NPRM
was prompted by reports of corrosion damage found on a certain SATCOM
high gain antenna adapter plate. In the NPRM, the FAA proposed to
require repetitive DETs of the SATCOM high gain antenna adapter plate
for corrosion and applicable on-condition actions. The FAA is issuing
this AD to prevent corrosion damage of the SATCOM high gain antenna
adapter plates. The unsafe condition, if not addressed, could result in
the SATCOM high gain antenna system parts departing and impacting the
airplane, which can cause damage that results in loss of continued safe
flight and landing.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from the Air Line Pilots Association,
International, (ALPA), Boeing, and a commenter who supported the NPRM
without change.
The FAA received additional comments from Cathay Pacific Airways
Limited (Cathay) and the Citizens Rulemaking Alliance. The following
presents the comments received on the NPRM and the FAA's response to
each comment.
Request To Revise the Applicability
Cathay requested that the FAA revise the applicability of the
proposed AD to exclude airplanes that have been modified in accordance
with a certain supplemental type certificate (STC) to remove the
Inmarsat Antenna and the related adapter plates (part numbers (P/Ns)
100-602074-000 and 100-602549-000).
The FAA disagrees. The FAA does not have sufficient information
regarding that STC to determine if the modification removes all
components associated with the unsafe condition. Operators may request
approval of an alternative method of compliance
[[Page 31885]]
(AMOC) under the provisions of paragraph (i) of this AD for airplanes
that have been modified in accordance with the STC. The FAA has not
revised this AD in response to this comment.
Request To Justify Forgoing Notice and Comment or Reopen Comment Period
The Citizens Rulemaking Alliance requested that the FAA either
provide its justification for finding good cause to bypass notice, if
invoked, or reopen the comment period for the non-immediate actions.
The commenter asserted the FAA's use of the good cause exemption
appears overbroad given the compliance is 1 month instead of before
further flight.
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 add to the
AD docket all materials incorporated by reference and extend the
comment period by at least 45 days after adding the material to the
docket. The commenter stated that the FAA's current practices for IBR
frequently fail to meet the legal and regulatory standards for
reasonable availability.
The FAA disagrees with extending the comment period. In the
preamble of the NPRM, the FAA notified the public that the IBR material
would be available for review at <a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-
2025-3422. This material was posted to the AD docket on October 1,
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 comply with the PRA if reporting is required. If reporting is not
required, the commenter requested the FAA clarify that in the AD.
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 Regulatory Flexibility Act (RFA) certification
that the AD will not have a significant economic impact on a
substantial number of small entities including significant alternatives
considered to minimize the burden on small operators without
compromising safety.
The FAA provides the following clarification. The RFA of 1980 (5
U.S.C. 601-612), as amended by the Small Business Regulatory
Enforcement Fairness Act of 1996 (Pub. L. 104-121) and the Small
Business Jobs Act of 2010 (Pub. L. 111-240), 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.
This AD will affect 11 domestic entities, of which eight are small
entities. The table below displays the industries of the small
entities, their average annual revenue, and the AD's estimated cost
burden relative to average annual revenue.
Number of Small Entities Affected by Industry and Cost Significance
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Cost per
NAICS \1\ Number of Average AD/annual
Number of affected entities code Description \2\ affected annual revenue
airplanes revenue (%)
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1.............................. 532411 Commercial Air, Rail, and Water 1 $1,000,000 0.09
Transportation Equipment
Rental and Leasing.
1.............................. 423860 Transportation Equipment and 1 5,590,000 0.02
Supplies Merchant Wholesalers.
1.............................. 481219 Other Freight Air 2 221,410 0.84
Transportation.
1.............................. 481112 Scheduled Freight Air 2 10,330,000 0.02
Transportation.
1.............................. 481212 Nonscheduled Chartered Freight 2 58,110 3.22
Air Transportation.
1.............................. 481212 Nonscheduled Chartered Freight 4 48,450,000 0.01
Air Transportation.
1.............................. 481212 Nonscheduled Chartered Freight 9 55,250,000 0.02
Air Transportation.
1.............................. 481212 Nonscheduled Chartered Freight 24 390,000,000 0.01
Air Transportation.
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\1\ North American Industrial Classification System.
\2\ Dun & Bradstreet. D&B Hoovers. Retrieved April 16, 2026. <a href="http://app.hoovers.dnb.com">app.hoovers.dnb.com</a>.
While the FAA has determined that this AD affects a substantial
number of small entities, the compliance cost of the AD relative to
each small entity's annual revenue is minimal. The FAA estimates the
total cost per affected airplane to be $935 (11 work-hours x $85 per
work-hour). There is one small business operator whose revenue impact
exceeds 3% based on the number of affected airplanes in their fleet,
however, seven small business entities have impacts that are below 1%
of the average small entity's annual revenue. Therefore, as provided in
section 605(b), the FAA certifies this AD will not result in a
significant economic impact on a substantial number of small entities.
The FAA did not change this AD as a result of this comment.
Request To Provide Additional Cost Information
The Citizens Rulemaking Alliance requested that the FAA provide an
explicit Unfunded Mandates Reform Act (UMRA) determination and a more
complete cost analysis. The commenter stated that, in addition to
estimated costs provided in the proposed AD, the FAA should also
consider airplane
[[Page 31886]]
downtime, scheduling disruptions, ferry flight and maintenance
positioning, cost of special tools, pricing of scarce parts,
engineering and planning time for unique configurations, and the
ongoing cost of repetitive inspections.
The FAA notes that in the preamble of the proposed AD, the FAA
certified that this regulation is not a ``significant regulatory
action'' under Executive Order 12866 and will not have an annual effect
on the economy of $100 million or more. Further, in the Costs of
Compliance section of the proposed AD, the FAA disclosed the number of
affected airplanes on the U.S. registry and the number of work hours
per affected airplane to estimate the cost of the AD on all U.S.-
operators per inspection cycle. The inspection must be repeated every
48 or 96 months, depending on findings. The FAA did not disclose an
estimated parts cost since this AD does not require any parts.
Additionally, the FAA considered the impact that this AD will have
on affected operators and determined this AD will not trigger any
downtime costs or scheduling disruptions because the requirements of
this AD can be performed during regularly scheduled maintenance. Since
the FAA has assessed and disclosed the total 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, it is not necessary to provide
additional information in the AD docket. 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. 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 747-23A2628 RB,
dated April 18, 2025. This material specifies procedures for repetitive
DETs of the SATCOM high gain antenna adapter plates for corrosion and
applicable on-condition actions. On-condition actions include repairing
the SATCOM high gain antenna adapter plate or replacing it with a new
or serviceable SATCOM high gain antenna adapter plate if any corrosion
found is less than or equal to 0.005 inch in depth; and replacing the
SATCOM high gain antenna adapter plate with a new or serviceable SATCOM
high gain antenna adapter plate if any corrosion found is greater than
0.005 inch in depth. 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 115 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs
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Cost on U.S.
Action Labor cost Parts cost Cost per product operators
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Detailed inspection............. 11 work-hours x $85 \1\ $0 $935 per inspection $107,525 per
per hour = $935 per cycle. inspection cycle.
inspection cycle.
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\1\ The FAA estimated operators would incur $85 in costs per labor hour, which is the weighted average fiscal
year (FY) 2026 fully loaded wage of an aircraft mechanic ($69.85) working 60% of the labor hours and a general
and operations manager ($108.15) working 40% of the labor hours. The FAA estimated these wages by taking
average the FY 2024 Bureau of Labor Statistics (BLS) air transportation industry average wage for aircraft
mechanics and general and operations managers (See: Occupational Employment and Wage Statistics Query System,
BLS (May 2024), <a href="http://data.bls.gov/oes/">data.bls.gov/oes/</a>); multiplying each wage by a fringe benefit factor of 1.42 (See: Employer
Cost for Employee Compensation--December 2024, BLS (2024), <a href="http://bls.gov/news.release/archives/ecec_03142025.pdf">bls.gov/news.release/archives/ecec_03142025.pdf</a>);
and adjusting these 2024 wages to 2026 dollars using an implicit Gross Domestic Product (GDP) Price Deflator
of 2.8% (See: Gross Domestic Product: Implicit Price Deflator, FRED (2026) <a href="http://fred.stlouisfed.org/series/GDPDEF">fred.stlouisfed.org/series/GDPDEF</a>).
The FAA estimates the following costs to do any necessary repairs
or 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 these repairs or replacements:
On-Condition Costs
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Action Labor cost Parts cost Cost per product
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Repair adapter plate..................... 5 work-hour x $85 per hour = $425 $0 $425
Replace adapter plate.................... 2 work-hour x $85 per hour = $170 18,000 18,170
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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
[[Page 31887]]
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:
2026-10-14 The Boeing Company: Amendment 39-23354; Docket No. FAA-
2025-3422; Project Identifier AD-2025-00763-T.
(a) Effective Date
This airworthiness directive (AD) is effective July 6, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all The Boeing Company Model 747-100, -100B,
-100B SUD, -200B, -200C, -200F, -300, -400, -400D, -400F, 747SP, and
747SR series airplanes, certificated in any category.
(d) Subject
Air Transport Association (ATA) of America Code 23,
Communications system.
(e) Unsafe Condition
This AD was prompted by reports of corrosion damage found on a
certain satellite communications (SATCOM) high gain antenna adapter
plate. The FAA is issuing this AD to prevent corrosion damage of the
SATCOM high gain antenna adapter plates. The unsafe condition, if
not addressed, could result in the SATCOM high gain antenna system
parts departing and impacting the airplane, which can cause damage
that results in loss of continued safe flight and landing.
(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 747-23A2628 RB, dated April 18, 2025, do
all applicable actions identified in, and in accordance with, the
Accomplishment Instructions of Boeing Alert Requirements Bulletin
747-23A2628 RB, dated April 18, 2025.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
747-23A2628, dated April 18, 2025, which is referred to in Boeing
Alert Requirements Bulletin 747-23A2628 RB, dated April 18, 2025.
(h) Exception to Requirements Bulletin Specifications
Where Boeing Alert Requirements Bulletin 747-23A2628 RB, dated
April 18, 2025, refers to the original issue date of Requirements
Bulletin 747-23A2628 RB, this AD requires using the effective date
of this AD.
(i) 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 (j)(1) of this AD. Information may be emailed to:
<a href="/cdn-cgi/l/email-protection#31707c7e72715750501f565e47"><span class="__cf_email__" data-cfemail="95d4d8dad6d5f3f4f4bbf2fae3">[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.
(j) Additional Information
(1) For more information about this AD, contact Camille Seay,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; phone: 817-222-5149; email: <a href="/cdn-cgi/l/email-protection#1a797b777376767f347634697f7b635a7c7b7b347d756c"><span class="__cf_email__" data-cfemail="3350525e5a5f5f561d5f1d4056524a735552521d545c45">[email protected]</span></a>.
(2) Material identified in this AD that is not incorporated by
reference is available at the address specified in paragraph (k)(3)
this AD.
(k) 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 747-23A2628 RB, dated
April 18, 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#b5d3c79bdcdbc6c5d0d6c1dcdadbf5dbd4c7d49bd2dac3"><span class="__cf_email__" data-cfemail="573125793e3924273234233e3839173936253679303821">[email protected]</span></a>.
Issued on May 11, 2026.
Lona C. Saccomando,
Acting Deputy Director, Integrated Certificate Management Division,
Aircraft Certification Service.
[FR Doc. 2026-10803 Filed 5-28-26; 8:45 am]
BILLING CODE 4910-13-P
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