[Federal Register Volume 91, Number 44 (Friday, March 6, 2026)]
[Rules and Regulations]
[Pages 10961-10965]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-04465]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-2285; Project Identifier MCAI-2025-01848-T;
Amendment 39-23278; AD 2026-05-05]
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 superseding Airworthiness Directive (AD) 2023-23-
02, which applied to all MHI RJ Aviation ULC Model CL-600-2B19
(Regional Jet Series 100 & 440), 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 2023-23-02
required, for certain airplanes, revising the existing maintenance or
inspection program, as applicable, to incorporate new or more
restrictive airworthiness limitations; and accomplishing certain
aircraft maintenance manual (AMM) tasks and corrective actions
following short-term or long-term storage. Since the FAA issued AD
2023-23-02, additional power control unit (PCU) disconnect findings
show that the task intervals must be reduced to allow earlier detection
of potential single PCU disconnect cases. This AD continues to require
certain actions in AD 2023-23-02 and requires repetitive operational
checks of the rudder PCUs and repetitive operational tests of the
elevator PCUs. The FAA is issuing this AD to address the unsafe
condition on these products.
DATES: This AD is effective March 23, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 23,
2026.
The FAA must receive comments on this AD by April 20, 2026.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to regulations.gov. Follow
the instructions for submitting comments.
Fax: 202-493-2251.
[[Page 10962]]
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.
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-2026-2285; 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:
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.
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-2026-2285.
FOR FURTHER INFORMATION CONTACT: Brenda L. Buitrago, 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 relevant data, views, or
arguments about this final rule. Send your comments using a method
listed under the ADDRESSES section. Include ``Docket No. FAA-2026-2285;
Project Identifier MCAI-2025-01848-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.
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 Brenda
L. Buitrago, 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
The FAA issued AD 2023-23-02, Amendment 39-22604 (88 FR 86574,
December 14, 2023) (AD 2023-23-02), for all MHI RJ Aviation ULC Model
CL-600-2B19 (Regional Jet Series 100 & 440), 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 2023-23-02 was
prompted by an MCAI originated by Transport Canada, which is the
aviation authority for Canada. Transport Canada issued Transport Canada
AD CF-2023-03, dated January 20, 2023 (Transport Canada AD CF-2023-03),
to correct an unsafe condition. Transport Canada AD CF-2023-03 was
prompted by reports of PCU rod end fractures due to pitting corrosion
and a determination that new or more restrictive airworthiness
limitations are necessary.
AD 2023-23-02 required, for certain airplanes, revising the
existing maintenance or inspection program, as applicable, to
incorporate new or more restrictive airworthiness limitations. AD 2023-
23-02 also required accomplishing certain AMM tasks and corrective
actions following short-term or long-term storage. The FAA issued AD
2023-23-02 to address fractured PCU rod ends. This condition, if not
addressed, could lead to a disconnect between the PCU and the elevator
or rudder control surface, resulting in potential loss of the control
surface function or inadequate flutter suppression.
Actions Since AD 2023-23-02 Was Issued
Since the FAA issued AD 2023-23-02, Transport Canada superseded
Transport Canada AD CF-2023-03 and issued Transport Canada AD CF-2025-
70, dated December 22, 2025 (Transport Canada AD CF-2025-70) (also
referred to as the MCAI), to correct an unsafe condition for all MHI RJ
Aviation ULC Model CL-600-2B19 (Regional Jet Series 100 & 440), 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. The MCAI states the manufacturer has determined that the PCU
rod end spherical bearing could seize, inducing a bending moment on the
PCU output rod. This repetitive bending of the rod end will eventually
lead to fatigue failure. Transport Canada AD CF-2018-29, dated November
2, 2018 (Transport Canada AD CF-2018-29) required detailed inspections
of the rudder and elevator PCU rod ends to allow timely detection of
pitting corrosion. Transport Canada AD CF-2023-03 required operators to
use the appropriate return-to-service tasks following short-term or
prolonged and long-term storage. In addition, Transport Canada AD CF-
2023-03 required, for certain airplanes, the incorporation of a revised
Certification Maintenance Requirement (CMR) task for the operational
check of each rudder PCU and a new CMR task for the operational check
of each elevator PCU to improve detection of potential single PCU
disconnect cases. The actions required by Transport Canada AD CF-2023-
03 are in addition to those required by Transport Canada AD CF-2018-29.
The MCAI also states, since issuance of Transport Canada AD CF-
2018-29 and Transport Canada AD CF-2023-03, the manufacturer has
identified additional PCU disconnect findings. Transport Canada AD CF-
2025-70 retains the requirements of Transport Canada AD CF-2023-03 and
requires accomplishment of certain AMM tasks for operational checks of
each rudder PCU and operational tests of each
[[Page 10963]]
elevator PCU to be performed at reduced intervals of within 200 hours
airtime or 3 months, whichever occurs first, to allow earlier detection
of potential single PCU disconnect cases.
Although Transport Canada AD CF-2025-70 states that the
requirements of Transport Canada AD CF-2023-03 are retained, only the
requirements for returning an airplane to service after short-term or
long-term storage are retained from that AD with no changes. Transport
Canada AD CF-2025-70 specifies accomplishing certain repetitive
operational checks of the rudder PCUs and repetitive operational tests
of the elevator PCUs in lieu of revising the existing maintenance or
inspection program, as applicable, to incorporate new or more
restrictive airworthiness limitations as specified in Transport Canada
AD CF-2023-03. The FAA has determined that these repetitive checks and
tests provide a different method of compliance and more restrictive
compliance times for addressing the unsafe condition, retain the same
underlying operational checks and tests as the airworthiness
limitations.
The FAA is issuing this AD to address the unsafe condition on these
products. You may examine the MCAI in the AD docket at regulations.gov
under Docket No. FAA-2026-2285.
Other Relevant Rulemaking
The FAA issued AD 2019-19-08, Amendment 39-19744 (84 FR 60902,
November 12, 2019) (AD 2019-19-08), which applies to certain MHI RJ
Aviation ULC Model CL-600-2B19 (Regional Jet Series 100 & 440), CL-600-
2C10 (Regional Jet Series 700, 701 & 702), CL-600-2D15 (Regional Jet
Series 705), CL-600-2D24 (Regional Jet Series 900), and CL-600-2E25
(Regional Jet Series 1000) airplanes. AD 2019-19-08 corresponds to
Transport Canada AD CF-2018-29, which is referenced in Transport Canada
AD CF-2023-03 and Transport Canada AD CF-2025-70. AD 2019-19-08
requires detailed inspections of the elevator PCU rod ends and
applicable corrective actions and prohibits using certain AMM tasks.
The actions required by AD 2019-19-08 are in addition to those required
by this AD and do not affect compliance with this AD.
Explanation of Retained Requirements
Although this AD does not explicitly restate the requirements of AD
2023-23-02, this AD retains certain requirements of AD 2023-23-02.
Those requirements are referenced in Transport Canada AD CF-2025-70,
which, in turn, is referenced in paragraph (g) of this AD.
Material Incorporated by Reference Under 1 CFR Part 51
Transport Canada AD CF-2025-70 specifies procedures for
accomplishing the following AMM tasks, as applicable:
Repetitive operational checks of the rudder PCUs.
Repetitive operational tests of the elevator PCUs.
Transport Canada AD CF-2025-70 also specifies procedures for
accomplishing the following AMM tasks and corrective actions, as
applicable, for returning an airplane to service after short-term or
long-term storage:
An operational test of the rudder PCUs.
An operational test of the elevator PCUs.
An operational test of the rudder control system.
An operational test of the elevator control system.
A detailed inspection of the rudder PCU rod end spherical
ball.
A detailed inspection of the elevator PCU rod end
spherical ball.
The corrective actions include making sure that the applicable
parts are moving or rotating correctly.
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 in other products of the same type design.
Requirements of This AD
This AD retains certain requirements of AD 2023-23-02. This AD
requires accomplishing the actions specified in Transport Canada AD CF-
2025-70 described previously, except for any differences identified as
exceptions in the regulatory text of this 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,
Transport Canada AD CF-2025-70 is incorporated by reference in this AD.
This AD, therefore, requires compliance with Transport Canada AD CF-
2025-70 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-2025-70 for compliance will
be available at regulations.gov under Docket No. FAA-2026-2285 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 the repetitive task intervals required by AD 2023-23-02 are not
adequate for detecting disconnects between the PCU and the elevator or
rudder control surface, which could result in loss of control surface
function or inadequate flutter suppression; thus, a shorter repetitive
task interval of 200 hours flight time or 3 months, whichever occurs
first, is needed. Failure to detect a latent flight-critical PCU
disconnect condition would increase risk to continued safe flight and
landing. Additionally, the compliance time 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
[[Page 10964]]
the FAA found good cause to forgo notice and comment.
Regulatory Flexibility Act
The requirements of the Regulatory Flexibility Act (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 711 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
Action Labor cost Parts cost Cost per product Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
Retained actions from AD 2023-23- Up to 8 work-hours $0 Up to $680........ Up to $483,480.
02. x $85 per hour =
$680.
New actions..................... Up to 8 work-hours $0 Up to $680........ Up to $483,480.
x $85 per hour =
$680.
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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:
0
a. Removing Airworthiness Directive (AD) 2023-23-02, Amendment 39-22604
(88 FR 86574, December 14, 2023); and
0
b. Adding the following new AD:
2026-05-05 MHI RJ Aviation ULC (Type Certificate Previously Held by
Bombardier, Inc.): Amendment 39-23278; Docket No. FAA-2026-2285;
Project Identifier MCAI-2025-01848-T.
(a) Effective Date
This airworthiness directive (AD) is effective March 23, 2026.
(b) Affected ADs
This AD replaces AD 2023-23-02, Amendment 39-22604 (88 FR 86574,
December 14, 2023) (AD 2023-23-02).
(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 (6) of this AD, certificated in any
category.
(1) Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes.
(2) Model CL-600-2C10 (Regional Jet Series 700, 701 & 702)
airplanes.
(3) Model CL-600-2C11 (Regional Jet Series 550) airplanes.
(4) Model CL-600-2D15 (Regional Jet Series 705) airplanes.
(5) Model CL-600-2D24 (Regional Jet Series 900) airplanes.
(6) Model CL-600-2E25 (Regional Jet Series 1000) airplanes.
(d) Subject
Air Transport Association (ATA) of America Code 27, Flight
controls.
(e) Unsafe Condition
This AD was prompted by reports of power control unit (PCU) rod
end fractures due to pitting corrosion and a determination that new
or more restrictive airworthiness limitations are necessary. This AD
was also prompted by additional PCU disconnect findings that show
the task intervals must be reduced to allow earlier detection of
potential single PCU disconnect cases. The FAA is issuing this AD to
address fractured PCU rod ends. This condition, if not addressed,
could lead to a disconnect between the PCU and the elevator or
rudder control surface, resulting in potential loss of the control
surface function or inadequate flutter suppression.
(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-2025-70, dated December 22,
2025 (Transport Canada AD CF-2025-70).
(h) Exception to Transport Canada AD CF-2025-70
(1) Where Transport Canada AD CF-2025-70 refers to its effective
date, this AD requires using the effective date of this AD.
(2) Where Transport Canada AD CF-2025-70 refers to hours
airtime, this AD requires using flight hours.
(3) Where paragraph A in Parts II and III of Transport Canada AD
CF-2025-70 specifies to repeat certain airplane maintenance manual
(AMM) task(s) ``every 200 hours airtime'', this AD requires
replacing that text with ``at the intervals not to exceed 200 flight
hours''.
(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
[[Page 10965]]
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].
(2) Contacting the Manufacturer: For any requirement in this AD
to obtain instructions from a manufacturer, the instructions must be
accomplished using 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 Brenda L. Buitrago,
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 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-2025-70, dated December 22, 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 February 27, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-04465 Filed 3-4-26; 4:15 pm]
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