Proposed Rule2026-18376
Airworthiness Directives; Bombardier, Inc. 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 9, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier, Inc., Model BD-700-2A12 airplanes. This proposed AD was prompted by reports of fuel leakage near rib 6 during production pressure testing. An investigation found oversized holes in a certain outboard shear-tie. This proposed AD would require an inspection of the fasteners and fastener holes at rib 6 for discrepancies 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 173 (Wednesday, September 9, 2026)</title>
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[Federal Register Volume 91, Number 173 (Wednesday, September 9, 2026)]
[Proposed Rules]
[Pages 57278-57281]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-18376]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-8797; Project Identifier MCAI-2025-01338-T]
RIN 2120-AA64
Airworthiness Directives; Bombardier, Inc. 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 certain Bombardier, Inc., Model BD-700-2A12 airplanes. This
proposed AD
[[Page 57279]]
was prompted by reports of fuel leakage near rib 6 during production
pressure testing. An investigation found oversized holes in a certain
outboard shear-tie. This proposed AD would require an inspection of the
fasteners and fastener holes at rib 6 for discrepancies 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 October 26,
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-2026-8797; 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, the mandatory continuing airworthiness
information (MCAI), any comments received, and other information. The
street address for Docket Operations is listed above.
Material Incorporated by Reference:
<bullet> For Transport Canada material identified in this proposed
AD, contact Transport Canada, Transport Canada National Aircraft
Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada;
telephone 888-663-3639; email <a href="/cdn-cgi/l/email-protection#e3b7a0cda28a91948c91978b8a8d869090a78a918680978a958690cea08c8d908a848d869087868d82958a8482818a8f8a9786cdb7a0a39780cd8480cd8082"><span class="__cf_email__" data-cfemail="eebaadc0af879c99819c9a8687808b9d9daa879c8b8d9a87988b9dc3ad81809d8789808b9d8a8b808f9887898f8c8782879a8bc0baadae9a8dc0898dc08d8f">[email protected]</span></a>. You may find this material on the
Transport Canada website at tc.canada.ca/en/aviation. It is also
available at <a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2026-8797.
<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.
FOR FURTHER INFORMATION CONTACT: Isabel Saltzman, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: 516-228-7300; email: <a href="/cdn-cgi/l/email-protection#41786c2037326c2f3820222e6c222e32012720206f262e37"><span class="__cf_email__" data-cfemail="774e5a1601045a190e1614185a1418043711161659101801">[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-2026-8797;
Project Identifier MCAI-2025-01338-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
Isabel Saltzman, Aviation Safety Engineer, FAA, 1600 Stewart Avenue,
Suite 410, Westbury, NY 11590; phone: 516-228-7300; email: <a href="/cdn-cgi/l/email-protection#380115594e4b155641595b57155b574b785e5959165f574e"><span class="__cf_email__" data-cfemail="a89185c9dedb85c6d1c9cbc785cbc7dbe8cec9c986cfc7de">[email protected]</span></a>. Any commentary that the FAA receives which is not
specifically designated as CBI will be placed in the public docket for
this rulemaking.
Background
Transport Canada, which is the aviation authority for Canada, has
issued Transport Canada AD CF-2025-39, dated August 7, 2025 (Transport
Canada AD CF-2025-39) (also referred to as the MCAI), to correct an
unsafe condition for certain Bombardier, Inc., Model BD-700-2A12
airplanes. The MCAI states that reports of fuel leakage near rib 6 were
found during production pressure testing. An investigation found five
oversized holes upon the removal of the doubler on rib 6 close to
stringer 8L. The oversized holes were found in the outboard shear-tie
between stringers 8L and 9L, attaching rib 6 to the lower skin of the
wing. A fatigue analysis of oversized holes in the inboard and outboard
shear-ties between stringers 8L and 9L attaching rib 6 to the skin of
the wing indicated the potential for crack formation. This condition,
if not addressed, could lead to failure of shear-ties, resulting in the
loss of redundant structure and the consequent loss of structural
integrity of the airplane.
The FAA is proposing this AD to address the unsafe condition on
these products.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-8797.
Material Incorporated by Reference Under 1 CFR Part 51
Transport Canada AD CF-2025-39 specifies procedures for conducting
an inspection of the fasteners at rib 6 for discrepancies (any gaps
under the nuts or evidence of nut loosening), and of the fastener holes
for discrepancies (oversizing, elongation, ovalization, and cracking),
and applicable on-condition actions. On-condition actions include
repair and reinstalling fasteners.
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.
FAA's Determination
These products have been approved by the civil aviation authority
of another country and are approved for operation in the United States.
Pursuant to the FAA's bilateral agreement with this State of Design
Authority, that authority has notified the FAA of the unsafe condition
described in the MCAI referenced above. The FAA is issuing this NPRM
after determining that the unsafe condition described previously is
likely to exist or develop in other products of the same type design.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in Transport Canada AD CF-2025-39 described previously, except for any
differences identified as exceptions in the regulatory text of this
proposed AD.
[[Page 57280]]
Explanation of Compliance Time That Specifies a Calendar Date
Transport Canada AD CF-2025-39 includes a compliance time that
specifies a calendar date. In determining this compliance time, a
fatigue analysis was done based on usage from the fleet leader of the
affected aircraft. To ensure that the unsafe condition was addressed
based on the original calculated compliance time, the compliance time
was adjusted, and the usage was set from the issuance date of
Bombardier Service Bulletin 700-57-7525, dated October 26, 2022, i.e.,
within 1,400 flight cycles from October 26, 2022. The FAA is adopting
this same compliance time.
Explanation of Required Compliance Information
In the FAA's ongoing efforts to improve the efficiency of the AD
process, the FAA developed a process to use some civil aviation
authority (CAA) ADs as the primary source of information for compliance
with requirements for corresponding FAA ADs. The FAA has been
coordinating this process with manufacturers and CAAs. As a result, the
FAA proposes to incorporate Transport Canada AD CF-2025-39 by reference
in the FAA final rule. This proposed AD would, therefore, require
compliance with Transport Canada AD CF-2025-39 in its entirety through
that incorporation, except for any differences identified as exceptions
in the regulatory text of this proposed AD. Material required by
Transport Canada AD CF-2025-39 for compliance will be available at
<a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2026-8797 after the FAA final rule
is published.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 13 airplanes of U.S. registry. The FAA estimates the following
costs to comply with this proposed AD:
Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Labor cost Parts cost product operators
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10 work-hours x $85 per hour = $850.......................... $0 $850 $11,050
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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 any
required actions. The FAA has no way of determining the number of
aircraft that might need this on-condition action:
Estimated Costs of On-Condition Actions
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Cost per
Labor cost Parts cost product
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39 work-hours x $85 per hour = $3,315. $635 $3,950
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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:
Bombardier, Inc.: Docket No. FAA-2026-8797; Project Identifier MCAI-
2025-01338-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by October 26, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to Bombardier, Inc., Model BD-700-2A12
airplanes, certificated
[[Page 57281]]
in any category, as identified in Transport Canada AD CF-2025-39,
dated August 7, 2025 (Transport Canada AD CF-2025-39).
(d) Subject
Air Transport Association (ATA) of America Code 57, Wings.
(e) Unsafe Condition
This AD was prompted by reports of fuel leakage near rib 6
during production pressure testing. An investigation found oversized
holes in a certain outboard shear-tie. Fatigue analysis of those
oversized holes indicated the potential for crack formation. The FAA
is issuing this AD to address the failure of shear-ties. The unsafe
condition, if not addressed, could result in the loss of redundant
structure and the consequent loss of structural integrity of the
airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Requirements
Except as specified in paragraphs (h) and (i) of this AD: Comply
with all required actions and compliance times specified in, and in
accordance with, Transport Canada AD CF-2025-39.
(h) Exception to Transport Canada AD CF-2025-39
(1) Where Transport Canada AD CF-2025-39 refers to its effective
date, this AD requires using the effective date of this AD.
(2) Where Transport Canada AD CF-2025-39 specifies to ``Inspect
and if required rework the fasteners and fastener holes at Rib 6, in
accordance with Section 2.B of the Accomplishment Instructions of
Bombardier Service Bulletin (SB) 700-57-7525 Revision 01, dated 13
January 2025 or later revisions approved by the Chief, Continuing
Airworthiness, Transport Canada'', this AD requires replacing that
text with ``Inspect in accordance with Section 2.B of the
Accomplishment Instructions of Bombardier Service Bulletin (SB) 700-
57-7525 Revision 01, dated 13 January 2025 or later revisions
approved by the Chief, Continuing Airworthiness, Transport Canada.
If any discrepancy (gap under a nut; evidence of nut loosening;
oversized, elongated, or ovalized hole; or cracking) is detected,
the discrepancy must be repaired before further flight using a
method approved by the Manager, International Validation Branch,
FAA; or Transport Canada; or Bombardier's Transport Canada Design
Approval Organization (DAO). If approved by the DOA, the approval
must include the DOA-authorized signature''.
(i) No Reporting Requirement
Although the material referenced in Transport Canada AD CF-2025-
39 specifies to submit certain information to the manufacturer, this
AD does not include that requirement.
(j) Additional AD Provisions
The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager,
International Validation 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
International Validation Branch, send it to the attention of the
person identified in paragraph (k) of this AD and email to:
<a href="/cdn-cgi/l/email-protection#f5b4b8bab6b5939494db929a83"><span class="__cf_email__" data-cfemail="aaebe7e5e9eacccbcb84cdc5dc">[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) Contacting the Manufacturer: For any requirement in this AD
to obtain instructions from a manufacturer, the instructions must be
accomplished using a method approved by the Manager, International
Validation Branch, FAA; or Transport Canada; or Bombardier's
Transport Canada Design Approval Organization (DAO). If approved by
the DAO, the approval must include the DAO-authorized signature.
(k) Additional Information
For more information about this AD, contact Isabel Saltzman,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: 516-228-7300; email: <a href="/cdn-cgi/l/email-protection#6a53470b1c194704130b0905470905192a0c0b0b440d051c"><span class="__cf_email__" data-cfemail="fbc2d69a8d88d695829a9894d6989488bb9d9a9ad59c948d">[email protected]</span></a>.
(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 this AD specifies otherwise.
(i) Transport Canada AD CF-2025-39, dated August 7, 2025.
(ii) [Reserved]
(3) For Transport Canada material identified in this AD, contact
Transport Canada, Transport Canada National Aircraft Certification,
159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; telephone 888-
663-3639; email <a href="/cdn-cgi/l/email-protection#06524528476f74716974726e6f68637575426f746365726f7063752b456968756f6168637562636867706f6167646f6a6f7263285245467265286165286567"><span class="__cf_email__" data-cfemail="e2b6a1cca38b90958d90968a8b8c879191a68b908781968b948791cfa18d8c918b858c879186878c83948b8583808b8e8b9687ccb6a1a29681cc8581cc8183">[email protected]</span></a>. You may find this material on
the Transport Canada website at tc.canada.ca/en/aviation.
(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#4325316d2a2d30332620372a2c2d032d2231226d242c35"><span class="__cf_email__" data-cfemail="d5b3a7fbbcbba6a5b0b6a1bcbabb95bbb4a7b4fbb2baa3">[email protected]</span></a>.
Issued on September 3, 2026.
Paul R. Bernado,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2026-18376 Filed 9-8-26; 8:45 am]
BILLING CODE 4910-13-P
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