Proposed Rule2026-06691
Airworthiness Directives; The Boeing Company Airplanes
Primary source
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Published
April 7, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for all The Boeing Company Model 787-8, 787-9, and 787-10 airplanes. This proposed AD was prompted by reports of fatigue cracks found on the thrust reverser (TR) outer V-blade (OVB) during scheduled maintenance and inspections. This proposed AD would require repetitive inspections of the upper, center, and lower segments of the OVB and the inner radius of the OVB for any crack 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 66 (Tuesday, April 7, 2026)</title>
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[Federal Register Volume 91, Number 66 (Tuesday, April 7, 2026)]
[Proposed Rules]
[Pages 17614-17616]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-06691]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-3471; Project Identifier AD-2025-01563-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 adopt a new airworthiness directive (AD)
for all The Boeing Company Model 787-8, 787-9, and 787-10 airplanes.
This proposed AD was prompted by reports of fatigue cracks found on the
thrust reverser (TR) outer V-blade (OVB) during scheduled maintenance
and inspections. This proposed AD would require repetitive inspections
of the upper, center, and lower segments of the OVB and the inner
radius of the OVB for any crack 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 May 22,
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-2026-3471; 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-2026-3471.
FOR FURTHER INFORMATION CONTACT: Tak Kobayashi, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3553; email: <a href="/cdn-cgi/l/email-protection#9fcbfef4fef7f6ecfeb1d4f0fdfee6feecf7f6dff9fefeb1f8f0e9"><span class="__cf_email__" data-cfemail="22764349434a4b51430c694d40435b43514a4b624443430c454d54">[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-2026-3471;
Project Identifier AD-2025-01563-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
Takahisa Kobayashi, Aviation Safety Engineer, FAA, 2200 South 216th
St., Des Moines, WA 98198; phone: 206-231-3553; email:
<a href="/cdn-cgi/l/email-protection#5a0e3b313b3233293b741135383b233b2932331a3c3b3b743d352c"><span class="__cf_email__" data-cfemail="6d390c060c05041e0c4326020f0c140c1e05042d0b0c0c430a021b">[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 has received a report indicating fatigue cracks were found
on the TR OVB during scheduled maintenance and inspections. The OVB and
the inner V-blade (IVB) are the primary load paths on the TR, and any
full-length crack could lead to loss of load path. This condition, if
not addressed, could cause TR structural failure during TR operation on
the ground, which could result in asymmetric reverse thrust, leading to
runway excursion, and the release of parts from the damaged TR, which
could hit the fuselage and result in injury to passengers or crew
members.
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-
SB780049-00 RB, Issue 001, dated August 12, 2025. This material
specifies procedures for performing, on the left and right TR halves on
both engines, a repetitive detailed inspection of the upper, center,
and lower segments of the OVB and a repetitive surface high frequency
eddy current (HFEC) inspection of the inner radius of the TR OVB for
any crack, and applicable on-condition actions. On-condition actions
include performing a surface HFEC inspection at the crack location,
[[Page 17615]]
performing a detailed inspection of the upper, center, and lower
segments of the OVB for any worn and missing dry film lubricant and
restoring the dry film lubricant as applicable, and replacing an
affected TR half.
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-2026-3471.
Interim Action
The FAA considers that this proposed AD would be an interim action.
The manufacturer is currently developing a terminating action that
would address the unsafe condition identified in this proposed AD. Once
this terminating action is developed, approved, and available, the FAA
might consider further rulemaking.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 194 airplanes of U.S. registry. The FAA estimates the following
costs to comply with this proposed AD:
Estimated Costs
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Cost on U.S.
Action Labor cost Parts cost Cost per product operators
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Inspection of the TR halves (left Up to 20 work-hours $0 Up to $1,700 per Up to $329,800 per
and right halves on both x $85 per hour = inspection cycle. inspection cycle.
engines) for cracks. $1,700 per
inspection cycle.
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The FAA estimates the following costs to do any necessary repairs
or replacements that would be required based on the results of the
proposed inspection. The agency has no way of determining the number of
aircraft that might need these repairs or replacements:
On-Condition Costs
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Action Labor cost Parts cost Cost per product
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HFEC of crack location................ 1 work-hour x $85 per $0 $85.
hour = $85.
Inspection of the TR halves (left and Up to 3 work-hours x $85 0 Up to $255.
right halves on both engines) for per hour = $255.
lubricant.
Replacement of TR..................... Up to 100 work-hours x (*) Up to $8,500.
$85 per hour = $8,500.
Restoration of dry film lubricant..... 7 work-hours x $85 per 0 $595.
hour = $595.
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* The FAA has received no definitive data on which to base the cost estimate for the parts cost for the TR
replacement 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 adding the following new airworthiness
directive:
The Boeing Company: Docket No. FAA-2026-3471; Project Identifier AD-
2025-01563-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by May 22, 2026.
(b) Affected ADs
None.
[[Page 17616]]
(c) Applicability
This AD applies to all The Boeing Company Model 787-8, 787-9,
and 787-10 airplanes, certificated in any category.
(d) Subject
Air Transport Association (ATA) of America Code 78, Engine
Exhaust.
(e) Unsafe Condition
This AD was prompted by reports of fatigue cracks found on the
thrust reverser (TR) outer V-blade (OVB) during scheduled
maintenance and inspections. The FAA is issuing this AD to address
fatigue cracking of the TR OVB. The unsafe condition, if not
addressed, could cause TR structural failure during TR operation on
the ground, which could result in asymmetric reverse thrust, leading
to runway excursion, and the release of parts from the damaged TR,
which could hit the fuselage and result in injury to passengers or
crew members.
(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-SB780049-00 RB, Issue 001,
dated August 12, 2025, do all applicable actions identified in, and
in accordance with, the Accomplishment Instructions of Boeing Alert
Requirements Bulletin B787-81205-SB780049-00 RB, Issue 001, dated
August 12, 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-SB780049-00, Issue 001, dated August 12, 2025, which is
referred to in Boeing Alert Requirements Bulletin B787-81205-
SB780049-00 RB, Issue 001, dated August 12, 2025.
(h) Exception to Requirements Bulletin Specifications
Where the Compliance Time column of the tables in the
``Compliance'' paragraph of Boeing Alert Requirements Bulletin B787-
81205-SB780049-00 RB, Issue 001, dated August 12, 2025, refer to the
Issue 001 date of Requirements Bulletin B787-81205-SB780049-00 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#a6e7ebe9e5e6c0c7c788c1c9d0"><span class="__cf_email__" data-cfemail="2b6a6664686b4d4a4a054c445d">[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 Tak Kobayashi,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; phone: 206-231-3553; email: <a href="/cdn-cgi/l/email-protection#cc98ada7ada4a5bfade287a3aeadb5adbfa4a58caaadade2aba3ba"><span class="__cf_email__" data-cfemail="f2a69399939a9b8193dcb99d90938b93819a9bb2949393dc959d84">[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 B787-81205-SB780049-00
RB, Issue 001, dated August 12, 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#2e485c0047405d5e4b4d5a4741406e404f5c4f00494158"><span class="__cf_email__" data-cfemail="8ceafea2e5e2fffce9eff8e5e3e2cce2edfeeda2ebe3fa">[email protected]</span></a>.
Issued on March 27, 2026.
Lona C. Saccomando,
Acting Deputy Director, Integrated Certificate Management Division,
Aircraft Certification Service.
[FR Doc. 2026-06691 Filed 4-6-26; 8:45 am]
BILLING CODE 4910-13-P
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