Rule2025-19784
Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier, Inc.) Airplanes
Primary source
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Published
November 5, 2025
Effective
November 20, 2025
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain 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), CL-600-2D24 (Regional Jet Series 900), and CL-600-2E25 (Regional Jet Series 1000) airplanes. This AD was prompted by reports of loose and missing bolts on the horizontal stabilizer (H-stab) anti- yaw steady fitting block. This AD requires repetitive torque checks of the H-stab anti-yaw steady fitting block bolts. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 90 Issue 212 (Wednesday, November 5, 2025)</title>
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[Federal Register Volume 90, Number 212 (Wednesday, November 5, 2025)]
[Rules and Regulations]
[Pages 49251-49254]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-19784]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-3995; Project Identifier MCAI-2025-01653-T;
Amendment 39-23180; AD 2025-22-02]
RIN 2120-AA64
Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate
Previously Held by Bombardier, Inc.) Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain 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), CL-600-2D24 (Regional Jet Series 900), and CL-600-2E25
(Regional Jet Series 1000) airplanes. This AD was prompted by reports
of loose and missing bolts on the horizontal stabilizer (H-stab) anti-
yaw steady fitting block. This AD requires repetitive torque checks of
the H-stab anti-yaw steady fitting block bolts. The FAA is issuing this
AD to address the unsafe condition on these products.
DATES: This AD is effective November 20, 2025.
The FAA must receive comments on this AD by December 22, 2025.
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-2025-3995; 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 final rule, 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 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#2a7e69046b43585d45585e4243444f59596e43584f495e435c4f590769454459434d444f594e4f444b5c434d4b484346435e4f047e696a5e49044d4904494b"><span class="__cf_email__" data-cfemail="abffe885eac2d9dcc4d9dfc3c2c5ced8d8efc2d9cec8dfc2ddced886e8c4c5d8c2ccc5ced8cfcec5caddc2cccac9c2c7c2dfce85ffe8ebdfc885ccc885c8ca">[email protected]</span></a>. You may find this material on the
Transport Canada website at tc.canada.ca/en/aviation.
<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-2025-3995.
FOR FURTHER INFORMATION CONTACT: Fatin Saumik, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: 516-228-7300; email: <a href="/cdn-cgi/l/email-protection#d8e1f5b9aeabf5b6a1b9bbb7f5bbb7ab98beb9b9f6bfb7ae"><span class="__cf_email__" data-cfemail="88b1a5e9fefba5e6f1e9ebe7a5ebe7fbc8eee9e9a6efe7fe">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written data, views, or arguments
about this final rule. Send your comments using a method listed under
the ADDRESSES section. Include ``Docket No. FAA-2025-3995; Project
Identifier MCAI-2025-01653-T'' at the beginning of your comments. The
most helpful comments reference a specific portion of the final rule,
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 final rule because of those comments.
[[Page 49252]]
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 final rule.
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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Fatin
Saumik, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: 516-228-7300; email: <a href="/cdn-cgi/l/email-protection#d0e9fdb1a6a3fdbea9b1b3bffdb3bfa390b6b1b1feb7bfa6"><span class="__cf_email__" data-cfemail="3b02165a4d481655425a5854165854487b5d5a5a155c544d">[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-2025-38, effective August 19, 2025
(Transport Canada AD CF-2025-38) (also referred to as the MCAI), to
correct an unsafe condition for certain MHI RJ Aviation ULC Model CL-
600-2C10 (Regional Jet Series 700, 701, and 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. The MCAI states that during the completion of a maintenance
task on the horizontal stabilizer, a bolt from the horizontal
stabilizer anti-yaw steady fitting block was missing. The missing bolt
and associated hardware were found lying on adjacent structure. Other
bolts in the same bolt group on the anti-yaw steady fitting block were
found to be loose. The anti-yaw steady fitting block bolts do not have
a secondary locking feature. Loose or missing bolts on the anti-yaw
steady fitting block when combined with a bird strike or gust loading
may result in loss of the horizontal stabilizer.
The FAA is issuing this AD to address loose or missing bolts on the
anti-yaw steady fitting block, which, when combined with a bird strike
or gust loading, may result in loss of the horizontal stabilizer and
consequent loss of control 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-2025-3995.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Transport Canada AD CF-2025-38, which specifies
procedures for repetitive torque checks of the H-stab anti-yaw steady
fitting block bolts. The torque check consists of inspecting the
tightening torque on the four attachment bolts that attach the steady
block by replacing any bolt or nut that is loose or missing and then
torquing all four bolts and nuts.
Transport Canada AD CF-2025-38 also specifies procedures to replace
the H-Stab anti-yaw steady fitting block hardware. The replacement
includes measuring four-hole diameters on the steady block and steady
fitting; rework (ream) any hole diameter if required; and installing
and torquing new hardware attachments (bolts, nuts, washers, and cotter
pins) to create a double safety device on the hardware that attach the
steady block to the steady fitting.
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 AD
after determining that the unsafe condition described previously is
likely to exist or develop on other products of the same type design.
Requirements of This AD
This AD requires accomplishing the actions specified in Transport
Canada AD CF-2025-38 described previously, except for any differences
identified as exceptions in the regulatory text of this AD. See
``Differences Between This AD and the MCAI'' for a discussion of the
general differences included in this AD.
Differences Between This AD and the MCAI
Paragraph C. of the MCAI specifies to replace the H-stab anti-yaw
steady fitting block hardware. The FAA is considering requiring this
replacement, which would terminate the repetitive torque checks
required by this AD. However, the planned compliance time for the
replacement would be long enough to allow for notice and opportunity
for public comments on the merits of the replacement. This AD therefore
seeks such comments, while allowing the replacement as an optional
terminating action for the repetitive torque checks.
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,
Transport Canada AD CF-2025-38 is incorporated by reference in this AD.
This AD requires compliance with Transport Canada AD CF-2025-38 in its
entirety through that incorporation, except for any differences
identified as exceptions in the regulatory text of this AD. Material
required by Transport Canada AD CF-2025-38 for compliance will be
available at <a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2025-3995 after this
AD is published.
Justification for Immediate Adoption and Determination of the Effective
Date
Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C.
551 et seq.) authorizes agencies to dispense with notice and comment
procedures for rules when the agency, for ``good cause,'' finds that
those procedures are ``impracticable, unnecessary, or contrary to the
public interest.'' Under this section, an agency, upon finding good
cause, may issue a final rule without providing notice and seeking
comment prior to issuance. Further, section 553(d) of the APA
authorizes agencies to make rules effective in less than thirty days,
upon a finding of good cause.
An unsafe condition exists that requires the immediate adoption of
this AD without providing an opportunity for public comments prior to
adoption. The FAA has found that the risk to the flying public
justifies forgoing notice and comment prior to adoption of this rule
because loose or missing bolts on
[[Page 49253]]
the anti-yaw steady fitting block, when combined with a bird strike or
gust loading, may result in loss of the horizontal stabilizer and
consequent loss of control of the airplane. Additionally, the
compliance time necessary to address this unsafe condition, as set
forth in this AD, is shorter than the time necessary for the public to
comment and for publication of the final rule. Accordingly, notice and
opportunity for prior public comment are impracticable and contrary to
the public interest pursuant to 5 U.S.C. 553(b).
In addition, the FAA finds that good cause exists pursuant to 5
U.S.C. 553(d) for making this amendment effective in less than 30 days,
for the same reasons the FAA found good cause to forgo notice and
comment.
Regulatory Flexibility Act (RFA)
The requirements of the RFA do not apply when an agency finds good
cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and
comment. Because the FAA has determined that it has good cause to adopt
this rule without notice and comment, RFA analysis is not required.
Costs of Compliance
The FAA estimates that this AD affects 597 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
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Labor cost Parts cost Cost per product Cost on U.S. operators
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Up to 6 work-hours x $85 per hour = $510. $0 Up to $510................. Up to $304,470.
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Estimated Costs for Optional Actions
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Labor cost Parts cost Cost per product
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7 work-hour x $85 per hour = $595.... $27 $622
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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:
Estimated Costs of On-Condition Actions
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Labor cost Parts cost Cost per product
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1 work-hourx $85 per hour = $85. Up to $28......... Up to $113.
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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
This AD will not have federalism implications under Executive Order
13132. This AD will 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 that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866, and
(2) Will not affect intrastate aviation in Alaska.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
The Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 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:
2025-22-02 MHI RJ Aviation ULC (Type Certificate Previously Held by
Bombardier, Inc.): Amendment 39-23180; Docket No. FAA-2025-3995;
Project Identifier MCAI-2025-01653-T.
(a) Effective Date
This airworthiness directive (AD) is effective November 20,
2025.
(b) Affected ADs
None.
(c) Applicability
This AD applies to 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), CL-600-2D24 (Regional Jet Series
900), and CL-600-2E25 (Regional Jet Series 1000) airplanes,
certificated in any category, as identified in Transport Canada AD
CF-2025-38, effective August 19, 2025 (Transport Canada AD CF-2025-
38).
[[Page 49254]]
(d) Subject
Air Transport Association (ATA) of America Code 55, Stabilizers.
(e) Unsafe Condition
This AD was prompted by reports of loose and missing bolts on
the horizontal stabilizer anti-yaw steady fitting block. The FAA is
issuing this AD to address loose or missing bolts on the anti-yaw
steady fitting block, which, when combined with a bird strike or
gust loading, may result in loss of the horizontal stabilizer and
consequent loss of control of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Requirements
Except as specified in paragraph (h) of this AD: Comply with all
required actions and compliance times specified in, and in
accordance with, Transport Canada AD CF-2025-38.
(h) Exception to Transport Canada AD CF-2025-38
(1) Where Transport Canada AD CF-2025-38 refers to its effective
date, this AD requires using the effective date of this AD.
(2) Where Transport Canada AD CF-2025-38 refers to hours air
time, this AD requires using flight hours.
(3) Where Transport Canada AD CF-2025-38 refers to the effective
date of Transport Canada AD CF-2024-24 (July 4, 2024), this AD
requires using the effective date of this AD.
(4) Where paragraph B. of Transport Canada AD CF-2025-38
specifies to repeat the torques check ``every 2,200 hours air time
from the previous inspection'', for this AD, replace that text with
``at intervals not to exceed 2,200 flight hours''.
(5) This AD does not adopt paragraph C. of Transport Canada AD
CF-2025-38.
(i) 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 (j) of this AD and email to:
<a href="/cdn-cgi/l/email-protection#befff3f1fdfed8dfdf90d9d1c8"><span class="__cf_email__" data-cfemail="296864666a694f4848074e465f">[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.
(j) Additional Information
For more information about this AD, contact Fatin Saumik,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: 516-228-7300; email: <a href="/cdn-cgi/l/email-protection#e8d1c5899e9bc58691898b87c58b879ba88e8989c68f879e"><span class="__cf_email__" data-cfemail="172e3a7661643a796e7674783a7478645771767639707861">[email protected]</span></a>.
(k) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) 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-2025-38, effective August 19, 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#5501167b143c27223a27213d3c3b302626113c273036213c23302678163a3b263c323b302631303b34233c3234373c393c21307b01161521367b32367b3634"><span class="__cf_email__" data-cfemail="9cc8dfb2ddf5eeebf3eee8f4f5f2f9efefd8f5eef9ffe8f5eaf9efb1dff3f2eff5fbf2f9eff8f9f2fdeaf5fbfdfef5f0f5e8f9b2c8dfdce8ffb2fbffb2fffd">[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#7c1a0e5215120f0c191f081513123c121d0e1d521b130a"><span class="__cf_email__" data-cfemail="670115490e0914170204130e0809270906150649000811">[email protected]</span></a>.
Issued on October 30, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2025-19784 Filed 11-3-25; 8:45 am]
BILLING CODE 4910-13-P
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