Proposed Rule2026-05007

Airworthiness Directives; The Boeing Company Airplanes

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Published
March 13, 2026

Issuing agencies

Transportation DepartmentFederal Aviation Administration

Abstract

The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 787-8, 787-9, and 787-10 airplanes. This proposed AD was prompted by a Boeing investigation for manufacturing errors and excessive preload forces at the lower side of body (SOB) splice plates common to the lower outboard wing skins. That investigation concluded that shim gaps may have exceeded engineering allowances, and high pull up forces on the components may cause fatigue cracks to form at the fastener holes. This proposed AD would require, depending on configuration, repetitive ultrasonic (UT) inspections at certain splice plates, rear spar terminal fittings, lower chords, front spar terminal fittings, and jack pads for any cracks; repetitive detailed inspections (DET) of certain splice plates for any cracks; and applicable on-condition actions. 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 49 (Friday, March 13, 2026)</title>
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[Federal Register Volume 91, Number 49 (Friday, March 13, 2026)]
[Proposed Rules]
[Pages 12312-12314]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-05007]


========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

========================================================================


Federal Register / Vol. 91, No. 49 / Friday, March 13, 2026 / 
Proposed Rules

[[Page 12312]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2026-2295; Project Identifier AD-2025-01361-T]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain The Boeing Company Model 787-8, 787-9, and 787-10 
airplanes. This proposed AD was prompted by a Boeing investigation for 
manufacturing errors and excessive preload forces at the lower side of 
body (SOB) splice plates common to the lower outboard wing skins. That 
investigation concluded that shim gaps may have exceeded engineering 
allowances, and high pull up forces on the components may cause fatigue 
cracks to form at the fastener holes. This proposed AD would require, 
depending on configuration, repetitive ultrasonic (UT) inspections at 
certain splice plates, rear spar terminal fittings, lower chords, front 
spar terminal fittings, and jack pads for any cracks; repetitive 
detailed inspections (DET) of certain splice plates for any cracks; and 
applicable on-condition actions. 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 April 27, 
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-2026-2295; 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-2026-2295.

FOR FURTHER INFORMATION CONTACT: Joseph Hodgin, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3962; email: <a href="/cdn-cgi/l/email-protection#066c697563766e286c286e6962616f684660676728616970"><span class="__cf_email__" data-cfemail="0e64617d6b7e6620642066616a6967604e686f6f20696178">[email&#160;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-2026-2295; 
Project Identifier AD-2025-01361-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 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 
Joseph Hodgin, Aviation Safety Engineer, FAA, 2200 South 216th St., Des 
Moines, WA 98198; phone: 206-231-3962; email: <a href="/cdn-cgi/l/email-protection#63090c1006130b4d094d0b0c07040a0d230502024d040c15"><span class="__cf_email__" data-cfemail="81ebeef2e4f1e9afebafe9eee5e6e8efc1e7e0e0afe6eef7">[email&#160;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 has received a report indicating that a Boeing 
investigation for manufacturing errors and excessive preload forces at 
the lower SOB splice plates common to the lower outboard wing skins 
concluded that shim gaps may have exceeded engineering allowances. High 
pull up forces on the components may cause fatigue cracks to form at 
the fastener holes. Structural assessment of the condition has found 
that the existing structural inspection program for the affected 
aircraft is not adequate to detect cracking in principal structural 
elements with sufficient probability prior to the loss of limit load 
capability. This condition, if not addressed, could result in 
undetected fatigue cracks that can grow to weaken primary wing 
structure until it cannot

[[Page 12313]]

sustain limit load and result in subsequent loss of continued safe 
flight and landing.

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 B787-81205-
SB570048 RB, Issue 001, dated August 11, 2025. This material specifies 
procedures for performing repetitive UT inspections depending on 
configuration, repetitive UT inspections at splice plate No. 1 and No. 
2, rear spar terminal fittings, lower chords, front spar terminal 
fittings, and jack pads for any cracks; repetitive DET of splice plates 
No. 1 and No. 2 for any cracks; and applicable on-condition actions. 
On-condition actions include 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

    This proposed AD would 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-2026-2295.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 17 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                Cost on U.S.
              Action                    Labor cost        Parts cost    Cost per product          operators
----------------------------------------------------------------------------------------------------------------
UT and DET inspections...........  Up to 286 work hours           $0  Up to $24,310 per     Up to $413,270 per
                                    x $85 per hour =                   inspection cycle.     inspection cycle.
                                    $24,310 per
                                    inspection cycle.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition repairs specified in this proposed AD.
    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some or all of the costs of 
this proposed 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

    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 adding the following new airworthiness 
directive:

The Boeing Company: Docket No. FAA-2026-2295; Project Identifier AD-
2025-01361-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by April 27, 2026.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 787-8, 787-9, and 
787-10 airplanes, certificated in any category, as identified in 
Boeing Alert Requirements Bulletin B787-81205-SB570048 RB, Issue 001 
dated August 11, 2025.

(d) Subject

    Air Transport Association (ATA) of America Code 57, Wings.

(e) Unsafe Condition

    This AD was prompted by a Boeing investigation for manufacturing 
errors and excessive preload forces at the lower side of body splice 
plates common to the lower outboard wing skins. That investigation 
concluded that shim gaps may have exceeded engineering allowances 
and high pull up forces on the components may cause fatigue cracks 
to form at the fastener holes. The FAA is issuing this AD to address 
improper shim gaps that may lead to fatigue cracks. The unsafe 
condition, if not addressed, could result in undetected fatigue 
cracks that can grow to weaken primary wing structure until it 
cannot sustain limit load and result in subsequent loss of continued 
safe flight and landing.

[[Page 12314]]

(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 B787-81205-SB570048 RB, Issue 001, dated 
August 11, 2025, do all applicable actions identified in, and in 
accordance with, the Accomplishment Instructions of Boeing Alert 
Requirements Bulletin B787-81205-SB570048 RB, Issue 001, dated 
August 11, 2025.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
B787-81205-SB570048, Issue 001, dated August 11, 2025, which is 
referred to in Boeing Alert Requirements Bulletin B787-81205-
SB570048 RB, Issue 001, dated August 11, 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 B787-
81205-SB570048 RB, Issue 001, dated August 11, 2025, refer to the 
Issue 001 date of the Requirements Bulletin B787-81205-SB570048 RB, 
this AD requires using the effective date of this AD.
    (2) Where Boeing Alert Requirements Bulletin B787-81205-SB570048 
RB, Issue 001, dated August 11, 2025, specifies contacting Boeing 
for repair instructions: This AD requires doing the repair 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 Continued Operational 
Safety Branch, 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#d0919d9f9390b6b1b1feb7bfa6"><span class="__cf_email__" data-cfemail="4a0b0705090a2c2b2b642d253c">[email&#160;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 Joseph Hodgin, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; phone: 206-231-3962; email: <a href="/cdn-cgi/l/email-protection#315b5e425441591f5b1f595e5556585f715750501f565e47"><span class="__cf_email__" data-cfemail="c2a8adb1a7b2aaeca8ecaaada6a5abac82a4a3a3eca5adb4">[email&#160;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 B787-81205-SB570048 RB, 
Issue 001, dated August 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#2d4b5f0344435e5d484e594442436d434c5f4c034a425b"><span class="__cf_email__" data-cfemail="afc9dd81c6c1dcdfcaccdbc6c0c1efc1ceddce81c8c0d9">[email&#160;protected]</span></a>.

    Issued on March 5, 2026.
Lona C. Saccomando,
Acting Deputy Director, Integrated Certificate Management Division, 
Aircraft Certification Service.
[FR Doc. 2026-05007 Filed 3-12-26; 8:45 am]
BILLING CODE 4910-13-P


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