Proposed Rule2026-05224
Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate Previously Held by 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
March 17, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for all MHI RJ Aviation ULC Model CL-600-2C10 (Regional Jet Series 700, 701 & 702), CL-600-2C11 (Regional Jet Series 550), CL-600-2D15 (Regional Jet Series 705), and CL-600-2D24 (Regional Jet Series 900) airplanes. This proposed AD was prompted by a determination that new or more restrictive airworthiness limitations are necessary. This proposed AD would require revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations. 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 51 (Tuesday, March 17, 2026)</title>
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[Federal Register Volume 91, Number 51 (Tuesday, March 17, 2026)]
[Proposed Rules]
[Pages 12695-12698]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-05224]
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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.
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Federal Register / Vol. 91, No. 51 / Tuesday, March 17, 2026 /
Proposed Rules
[[Page 12695]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-2714; Project Identifier MCAI-2025-00827-T]
RIN 2120-AA64
Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate
Previously Held by 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 all MHI RJ Aviation ULC Model CL-600-2C10 (Regional Jet Series 700,
701 & 702), CL-600-2C11 (Regional Jet Series 550), CL-600-2D15
(Regional Jet Series 705), and CL-600-2D24 (Regional Jet Series 900)
airplanes. This proposed AD was prompted by a determination that new or
more restrictive airworthiness limitations are necessary. This proposed
AD would require revising the existing maintenance or inspection
program, as applicable, to incorporate new or more restrictive
airworthiness limitations. 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 1,
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-2026-2714; 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#8cd8cfa2cde5fefbe3fef8e4e5e2e9ffffc8e5fee9eff8e5fae9ffa1cfe3e2ffe5ebe2e9ffe8e9e2edfae5ebedeee5e0e5f8e9a2d8cfccf8efa2ebefa2efed"><span class="__cf_email__" data-cfemail="edb9aec3ac849f9a829f99858483889e9ea9849f888e99849b889ec0ae82839e848a83889e8988838c9b848a8c8f8481849988c3b9aead998ec38a8ec38e8c">[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-2026-2714.
<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#a99084c8dfda84c7d0c8cac684cac6dae9cfc8c887cec6df"><span class="__cf_email__" data-cfemail="ebd2c68a9d98c685928a8884c6888498ab8d8a8ac58c849d">[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-2026-2714;
Project Identifier MCAI-2025-00827-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#4b72662a3d386625322a2824662824380b2d2a2a652c243d"><span class="__cf_email__" data-cfemail="a1988cc0d7d28ccfd8c0c2ce8cc2ced2e1c7c0c08fc6ced7">[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-2025-26, dated May 6, 2025 (Transport
Canada AD CF-2025-26) (also referred to as the MCAI), to correct an
unsafe condition for all MHI RJ Aviation ULC (Type Certificate
previously held by Bombardier, Inc.) Model CL-600-2C10 (Regional Jet
Series 700, 701 & 702), CL-600-2C11 (Regional Jet Series 550), CL-600-
2D15 (Regional Jet Series 705), and CL-600-2D24 (Regional Jet Series
900) airplanes. The MCAI states that new or more restrictive
airworthiness limitations have been developed. The manufacturer
introduced changes to four airworthiness limitation items (ALIs) and
added four new ALIs to Maintenance Requirements Manual (MRM) CSP B-053,
Part 2, Section 2, ``Structural Inspections,'' and Section 3, ``Safe
Life Components,'' Revision 28,
[[Page 12696]]
dated June 25, 2024. These changes are the result of the latest damage
tolerance analyses that revealed the need for more restrictive
inspections than initially assumed.
The FAA is proposing this AD to address new or more restrictive
structural inspections and safe life limits. The unsafe condition, if
not addressed, could result in the loss of structural integrity of the
airplane.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-2714.
Other Related Rulemaking
The FAA issued AD 2025-25-03, Amendment 39-23211 (90 FR 57680,
December 12, 2025) (AD 2025-25-03), which applies to all MHI RJ
Aviation ULC Model CL-600-2C10 (Regional Jet Series 700, 701 & 702),
CL-600-2C11 (Regional Jet Series 550), CL-600-2D15 (Regional Jet Series
705), CL-600-2D24 (Regional Jet Series 900), and CL-600-2E25 (Regional
Jet Series 1000) airplanes. AD 2025-25-03 requires revising the
existing maintenance or inspection program, as applicable, to
incorporate new or more restrictive airworthiness limitations.
Accomplishing the actions in this proposed AD would terminate the
corresponding requirements of AD 2025-25-03 for the tasks identified in
the material referenced in Transport Canada AD CF-2025-26 only.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Transport Canada AD CF-2025-26, which specifies
new or more restrictive airworthiness limitations for airplane
structures and safe life limits. 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 revising the existing maintenance or
inspection program, as applicable, to incorporate new or more
restrictive airworthiness limitations, which are specified in Transport
Canada AD CF-2025-26 described previously, as incorporated by
reference. Any differences with Transport Canada AD CF-2025-26 are
identified as exceptions in the regulatory text of this proposed AD.
This proposed AD would require revisions to certain operator
maintenance documents to include new actions (e.g., inspections).
Compliance with these actions is required by 14 CFR 91.403(c). For
airplanes that have been previously modified, altered, or repaired in
the areas addressed by this proposed AD, the operator may not be able
to accomplish the actions described in the revisions. In this
situation, to comply with 14 CFR 91.403(c), the operator must request
approval for an alternative method of compliance (AMOC) according to
paragraph (k)(1) of this proposed AD.
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-2025-26 by reference
in the FAA final rule. This proposed AD would, therefore, require
compliance with Transport Canada AD CF-2025-26 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-2025-26 for compliance will be available at
<a href="http://regulations.gov">regulations.gov</a> by searching for and locating Docket No. FAA-2026-2714
after the FAA final rule is published.
Airworthiness Limitation ADs Using the New Process
The FAA's process of incorporating by reference MCAI ADs as the
primary source of information for compliance with corresponding FAA ADs
has been limited to certain MCAI ADs (primarily those with service
bulletins as the primary source of information for accomplishing the
actions required by the FAA AD). However, the FAA is now expanding the
process to include MCAI ADs that require a change to airworthiness
limitation documents, such as airworthiness limitation sections.
For these ADs that incorporate by reference an MCAI AD that changes
airworthiness limitations, the FAA requirements are unchanged.
Operators must revise the existing maintenance or inspection program,
as applicable, to incorporate the information specified in the new
airworthiness limitation document. The airworthiness limitations must
be followed according to 14 CFR 91.403(c) and 91.409(e).
The previous format of the airworthiness limitation ADs included a
paragraph that specified that no alternative actions (e.g.,
inspections) or intervals may be used unless the actions and intervals
are approved as an AMOC in accordance with the procedures specified in
the AMOC paragraph under ``Additional AD Provisions.'' This new format
includes a ``Provisions for Alternative Actions and Intervals''
paragraph that does not specifically refer to AMOCs, but operators may
still request an AMOC to use an alternative action or interval.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 589 airplanes of U.S. registry. The FAA estimates the following
costs to comply with this proposed AD:
The FAA has determined that revising the existing maintenance or
inspection program takes an average of 90 work-hours per operator,
although the agency recognizes that this number may vary from operator
to operator. Since operators incorporate maintenance or inspection
program changes for their affected fleet(s), the FAA has determined
that a per-operator estimate is more accurate than a per-airplane
estimate. Therefore, the agency estimates the average total cost per
operator to be $7,650 (90 work-hours x $85 per work-hour).
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
[[Page 12697]]
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 has 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:
MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier,
Inc.): Docket No. FAA-2026-2714; Project Identifier MCAI-2025-00827-
T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by May 1, 2026.
(b) Affected ADs
This AD affects AD 2025-25-03, Amendment 39-23211 (90 FR 57680,
December 12, 2025) (AD 2025-25-03).
(c) Applicability
This AD applies to all MHI RJ Aviation ULC (Type Certificate
previously held by Bombardier, Inc.) airplanes identified in
paragraphs (c)(1) through (4) of this AD, certificated in any
category.
(1) Model CL-600-2C10 (Regional Jet Series 700, 701 & 702)
airplanes.
(2) Model CL-600-2C11 (Regional Jet Series 550) airplanes.
(3) Model CL-600-2D15 (Regional Jet Series 705) airplanes.
(4) Model CL-600-2D24 (Regional Jet Series 900) airplanes.
(d) Subject
Air Transport Association (ATA) of America Code 05, Time Limits/
Maintenance Checks.
(e) Unsafe Condition
This AD was prompted by a determination that new or more
restrictive airworthiness limitations are necessary. The FAA is
issuing this AD to address new or more restrictive structural
inspections and safe life limits. The unsafe condition, if not
addressed, could result in the loss of structural integrity of the
airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Requirements
Within 30 days after the effective date of this AD: Comply with
all required actions specified in, and in accordance with, Transport
Canada AD CF-2025-26, dated May 6, 2025 (Transport Canada AD CF-
2025-26), except as specified in paragraph (h) of this AD.
(h) Exception to Transport Canada AD CF-2025-26
(1) Where the ``Corrective Actions'' section of Transport Canada
AD CF-2025-26 specifies to ``Within the thresholds and repeat
intervals identified within the tasks, or discard time, as
applicable, complete the new or more restrictive limitations
contained in the ALI sections of the MHIRJ MRM Part 2 publication
identified in Table 1 below, as applicable to the aeroplane model
and configuration.'', this AD requires replacing that text with
``Revise the existing maintenance or inspection program, as
applicable, by incorporating the new and revised ALI tasks
identified in Table 1 of Transport Canada AD CF-2025-26.''
(2) The initial compliance time for doing the tasks specified in
Table 1 of Transport Canada AD CF-2025-26 is at the applicable
threshold and discard time as specified in the material referenced
in Transport Canada AD CF-2025-26, or within 30 days after the
effective date of this AD, whichever occurs later.
(i) Provisions for Alternative Actions and Intervals
After the existing maintenance or inspection program has been
revised as required by paragraph (g) of this AD, no alternative
actions (e.g., inspections) and intervals are allowed unless they
are approved as specified in the provisions of the ``Corrective
Actions'' section of Transport Canada AD CF-2025-26.
(j) Terminating Action for Certain Tasks Required by AD 2025-25-03
Accomplishing the actions required by this AD terminates the
corresponding requirements of AD 2025-25-03 for the tasks identified
in the material referenced in Transport Canada AD CF-2025-26 only.
(k) 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 (l) of this AD and email to:
<a href="/cdn-cgi/l/email-protection#46070b09050620272768212930"><span class="__cf_email__" data-cfemail="d3929e9c9093b5b2b2fdb4bca5">[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 MHI RJ Aviation
ULC's Transport Canada Design Approval Organization (DAO). If
approved by the DAO, the approval must include the DAO-authorized
signature.
(l) 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#4c75612d3a3f6122352d2f23612f233f0c2a2d2d622b233a"><span class="__cf_email__" data-cfemail="b58c98d4c3c698dbccd4d6da98d6dac6f5d3d4d49bd2dac3">[email protected]</span></a>.
(m) 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-2025-26, dated May 6, 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#d08493fe91b9a2a7bfa2a4b8b9beb5a3a394b9a2b5b3a4b9a6b5a3fd93bfbea3b9b7beb5a3b4b5beb1a6b9b7b1b2b9bcb9a4b5fe849390a4b3feb7b3feb3b1"><span class="__cf_email__" data-cfemail="8fdbcca1cee6fdf8e0fdfbe7e6e1eafcfccbe6fdeaecfbe6f9eafca2cce0e1fce6e8e1eafcebeae1eef9e6e8eeede6e3e6fbeaa1dbcccffbeca1e8eca1ecee">[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.
[[Page 12698]]
(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#385e4a1651564b485d5b4c5157567856594a59165f574e"><span class="__cf_email__" data-cfemail="b5d3c79bdcdbc6c5d0d6c1dcdadbf5dbd4c7d49bd2dac3">[email protected]</span></a>.
Issued on March 12, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-05224 Filed 3-16-26; 8:45 am]
BILLING CODE 4910-13-P
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