Proposed Rule2026-07931
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
April 23, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to supersede Airworthiness Directive (AD) 2021-02-13, which applies to certain The Boeing Company Model 737-600, -700, -700C, -800, and -900 series airplanes. AD 2021-02-13 requires inspections of the fuselage skin and bear strap at the forward galley door between certain stations for cracks, and applicable on-condition actions. Since the FAA issued AD 2021-02-13, a report was received of cracking outside the required inspection area, and it has been determined that additional airplanes may be subject to the identified unsafe condition. This proposed AD would continue to require the actions of AD 2021-02-13 and would add airplanes to the applicability. This proposed AD would also add inspections for an extended inspection area. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 91 Issue 78 (Thursday, April 23, 2026)</title>
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[Federal Register Volume 91, Number 78 (Thursday, April 23, 2026)]
[Proposed Rules]
[Pages 21744-21747]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-07931]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-3865; Project Identifier AD-2025-01395-T]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2021-02-13, which applies to certain The Boeing Company Model 737-600,
-700, -700C, -800, and -900 series airplanes. AD 2021-02-13 requires
inspections of the fuselage skin and bear strap at the forward galley
door between certain stations for cracks, and applicable on-condition
actions. Since the FAA issued AD 2021-02-13, a report was received of
cracking outside the required inspection area, and it has been
determined that additional airplanes may be subject to the identified
unsafe condition. This proposed AD would continue to require the
actions of AD 2021-02-13 and would add airplanes to the applicability.
This proposed AD would also add inspections for an extended inspection
area. The FAA is proposing this AD to address the unsafe condition on
these products.
DATES: The FAA must receive comments on this proposed AD by June 8,
2026.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="http://regulations.gov">regulations.gov</a>. Follow
the instructions for submitting comments.
<bullet> Fax: 202-493-2251.
<bullet> Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
<bullet> Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-3865; 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 NPRM, any comments received, and other
information. The street address for Docket Operations is listed above.
Material Incorporated by Reference:
<bullet> For Boeing material identified in this proposed 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-2026-3865.
FOR FURTHER INFORMATION CONTACT: Luis Cortez-Muniz, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3958; email: <a href="/cdn-cgi/l/email-protection#c1adb4a8b2efa0efa2aeb3b5a4bbecacb4afa8bb81a7a0a0efa6aeb7"><span class="__cf_email__" data-cfemail="e9859c809ac788c78a869b9d8c93c4849c878093a98f8888c78e869f">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments using a method listed
under the ADDRESSES section. Include ``Docket No. FAA-2026-3865;
Project Identifier AD-2025-01395-T'' at the beginning of your comments.
The most helpful comments reference a specific portion of the proposal,
explain the reason for any recommended change, and include supporting
data. The FAA will consider all comments received by the closing date
and may amend this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
<a href="http://regulations.gov">regulations.gov</a>, including any personal information you provide. The
agency will also post a report summarizing each
[[Page 21745]]
substantive verbal contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to Luis
Cortez-Muniz, Aviation Safety Engineer, FAA, 2200 South 216th St., Des
Moines, WA 98198; phone: 206-231-3958; email: <a href="/cdn-cgi/l/email-protection#d9b5acb0aaf7b8f7bab6abadbca3f4b4acb7b0a399bfb8b8f7beb6af"><span class="__cf_email__" data-cfemail="7519001c065b145b161a0701100f5818001b1c0f351314145b121a03">[email protected]</span></a>. Any commentary that the FAA receives that is not
specifically designated as CBI will be placed in the public docket for
this rulemaking.
Background
The FAA issued AD 2021-02-13, Amendment 39-21396 (86 FR 10776,
February 23, 2021) (AD 2021-02-13), for certain The Boeing Company
Model 737-600, -700, -700C, -800, and -900 series airplanes. AD 2021-
02-13 was prompted by reports of cracks in the bear strap from station
(STA) 290 to STA 296, and between stringers S-8R and S-9R, sometimes
common to fasteners in the gap cover and emanating from rough sanding
marks found on the surface of the bear strap. AD 2021-02-13 requires
inspections of the fuselage skin and bear strap at the forward galley
door between certain stations for cracks, and applicable on-condition
actions. The agency issued AD 2021-02-13 to address cracking of the
bear strap, which could result in severing of the bear strap, possibly
leading to uncontrolled decompression and loss of structural integrity
of the airplane.
Actions Since AD 2021-02-13 Was Issued
Since the FAA issued AD 2021-02-13, the FAA received a report that
during routine maintenance, a crack was found on the forward galley
door bear strap of a Model 737-900ER series airplane, which is not
included in the applicability of AD 2021-02-13. In addition, cracks
were found in the bear strap between stringers S-7R and S-9R, and the
FAA determined that inspections of the surrounding stub frame for
cracking are necessary. The FAA has determined that these additional
areas require inspections, and Model 737-600, -700, -700C, -800, -900,
and -900ER series airplanes having line numbers 1763 and subsequent are
subject to the same unsafe condition.
FAA's Determination
The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or develop on other
products of the same type design.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Boeing Alert Requirements Bulletin 737-53A1383 RB,
Revision 3, dated July 30, 2025. This material specifies the following
procedures including options, depending on configuration, and
applicable on-condition actions:
<bullet> Internal general visual inspection of the bear strap and
external general visual inspection of the fuselage skin and gap cover
for any repair.
<bullet> External general visual inspection of the fuselage skin
and gap cover for any external repair.
<bullet> Internal general visual inspection of the forward galley
door cutout stub frame for any repair.
On-condition actions include obtaining and following alternative
inspection instructions and doing the inspections if repairs are found,
repetitive HFEC inspections for cracks, low frequency eddy current
(LFEC) inspections for cracks, and replacement or repair.
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.
Proposed AD Requirements in This NPRM
Although this proposed AD does not explicitly restate the
requirements of AD 2021-02-13, this proposed AD would retain all of the
requirements of AD 2021-02-13. Those requirements are referenced in the
material identified previously, which, in turn, is referenced in
paragraph (g) of this proposed AD.
This proposed AD would revise the applicability to add Model 737-
900ER series airplanes and would add inspections for an extended
inspection area. This proposed AD would also require accomplishing the
actions specified in the material already described, except for any
differences identified as exceptions in the regulatory text of this
proposed AD.
For information on the procedures and compliance times, see this
material at <a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2026-3865.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 1,965 airplanes of U.S. registry. The FAA estimates the
following costs to comply with this proposed AD:
Estimated Costs for Required Actions
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Cost on U.S.
Action Labor cost Parts cost Cost per product operators
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Inspection (retained action from Up to 28 work-hours $0 Up to $2,380....... Up to $4,676,700.
AD 2021-02-13). x $85 per hour =
$2,380.
Inspection of the stub frame (new Up to 25 work-hours 0 Up to 2,125........ Up to 4,175,625.
proposed action). x $85 per hour =
$2,125.
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The FAA estimates the following costs to do any necessary on-
condition action 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 this on-condition action:
[[Page 21746]]
On-Condition Costs
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Action Labor cost Parts cost Cost per product
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External HFEC and LFEC inspection for Up to 28 work-hours x $85 per $0 Up to $2,380.
cracks. hour = $2,380.
HFEC inspection for cracks............ Up to 27 work-hours per $0 Up to $2,295 per
inspection cycle. inspection cycle.
Stub frame replacement................ 35 work-hours x $85 per hour = $1,400 $4,375.
$2,975.
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The FAA has received no definitive data on which to base the cost
estimates for the bear strap replacement and other on-condition actions
specified in this proposed AD.
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
The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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 Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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) 2021-02-13, Amendment 39-21396
(86 FR 10776, February 23, 2021), and
0
b. Adding the following new AD:
The Boeing Company: Docket No. FAA-2026-3865; Project Identifier AD-
2025-01395-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by June 8, 2026.
(b) Affected ADs
This AD replaces AD 2021-02-13, Amendment 39-21396 (86 FR 10776,
February 23, 2021) (AD 2021-02-13).
(c) Applicability
This AD applies to all The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes, certificated in any
category.
(d) Subject
Air Transport Association (ATA) of America Code 53, Fuselage.
(e) Unsafe Condition
This AD was prompted by reports of cracks in the bear strap from
station (STA) 290 to STA 296, and between stringers S-7R and S-9R,
sometimes common to fasteners in the gap cover and emanating from
rough sanding marks found on the surface of the bear strap, and by a
report of cracking outside the required inspection area. The FAA is
issuing this AD to address cracking of the fuselage skin, bear
strap, and stub frame. The unsafe condition, if not addressed, could
result in severing of the bear strap, possibly leading to
uncontrolled decompression and loss of structural integrity of the
airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Inspections and Corrective Actions
Except as specified by paragraph (h) of this AD: At the
applicable times specified in the ``Compliance'' paragraph of Boeing
Alert Requirements Bulletin 737-53A1383 RB, Revision 3, dated July
30, 2025, do all applicable actions identified in, and in accordance
with, the Accomplishment Instructions of Boeing Alert Requirements
Bulletin 737-53A1383 RB, Revision 3, dated July 30, 2025.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
737-53A1383, Revision 3, dated July 30, 2025, which is referred to
in Boeing Alert Requirements Bulletin 737-53A1383 RB, Revision 3,
dated July 30, 2025.
(h) Exceptions to Requirements Bulletin Specifications
(1) Where the Compliance Time columns of the tables in the
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 737-
53A1383 RB, Revision 3, dated July 30, 2025, refer to the Revision 2
issue date of Requirements Bulletin 737-53A1383 RB, this AD requires
using the effective date of this AD.
(2) Where Boeing Alert Requirements Bulletin 737-53A1383 RB,
Revision 3, dated July 30, 2025, specifies contacting Boeing for
alternative inspections: This AD requires doing the alternative
inspections and applicable on-condition actions using a method
approved in accordance with the procedures specified in paragraph
(i) 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 certification office,
send it to the attention of the person identified in paragraph (j)
of this AD. Information may be emailed to: <a href="/cdn-cgi/l/email-protection#5a1b1715191a3c3b3b743d352c"><span class="__cf_email__" data-cfemail="70313d3f33301611115e171f06">[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
[[Page 21747]]
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.
(3) AMOCs for repairs approved for AD 2021-02-13 are approved as
AMOCs for the corresponding provisions of Boeing Alert Requirement
Bulletin 737-53A1383, Revision 3, dated July 30, 2025, that are
required by paragraph (g) of this AD, for the area covered by the
repair only.
(j) Additional Information
For more information about this AD, contact Luis Cortez-Muniz,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; phone: 206-231-3958; email: <a href="/cdn-cgi/l/email-protection#e488918d97ca85ca878b9690819ec989918a8d9ea4828585ca838b92"><span class="__cf_email__" data-cfemail="9cf0e9f5efb2fdb2fff3eee8f9e6b1f1e9f2f5e6dcfafdfdb2fbf3ea">[email protected]</span></a>.
(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 737-53A1383 RB, Revision
3, dated July 30, 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#dcbaaef2b5b2afacb9bfa8b5b3b29cb2bdaebdf2bbb3aa"><span class="__cf_email__" data-cfemail="395f4b1750574a495c5a4d5056577957584b58175e564f">[email protected]</span></a>.
Issued on April 21, 2026.
Victor Wicklund,
Acting Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2026-07931 Filed 4-22-26; 8:45 am]
BILLING CODE 4910-13-P
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