Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier, Inc.) Airplanes

[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 [www.gpo.gov]
[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 regulations.gov. 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 regulations.gov 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 [email protected]. 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 regulations.gov 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: [email protected].

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 
regulations.gov, 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: [email protected]. 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 regulations.gov 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 regulations.gov 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
----------------------------------------------------------------------------------------------------------------
                Labor cost                  Parts cost        Cost per product          Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
Up to 6 work-hours x $85 per hour = $510.           $0  Up to $510.................  Up to $304,470.
----------------------------------------------------------------------------------------------------------------


                  Estimated Costs for Optional Actions
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              Labor cost                Parts cost     Cost per product
------------------------------------------------------------------------
7 work-hour x $85 per hour = $595....          $27                 $622
------------------------------------------------------------------------

    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
------------------------------------------------------------------------
           Labor cost                 Parts cost       Cost per product
------------------------------------------------------------------------
1 work-hourx $85 per hour = $85.  Up to $28.........  Up to $113.
------------------------------------------------------------------------

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: 
[email protected]. 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: [email protected].

(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 [email protected]. 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 www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    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]
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