[Federal Register Volume 90, Number 160 (Thursday, August 21, 2025)]
[Proposed Rules]
[Pages 40780-40784]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-15998]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-2261; Project Identifier MCAI-2024-00717-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).

-----------------------------------------------------------------------

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), CL-600-2D24 (Regional Jet Series 900), and 
CL-600-2E25 (Regional Jet Series 1000) 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 October 6, 
2025.

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.

[[Page 40781]]

     Fax: 202-493-2251.
     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-2025-2261; 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:
     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 [email protected]. You may find this material on the 
Transport Canada website at tc.canada.ca/en/aviation. It is also 
available at regulations.gov under Docket No. FAA-2025-2261.
     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: 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 relevant data, views, or 
arguments about this proposal. Send your comments using a method listed 
under the ADDRESSES section. Include ``Docket No. FAA-2025-2261; 
Project Identifier MCAI-2024-00717-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 
regulations.gov, 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 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-2024-41, dated December 5, 2024 
(Transport Canada AD CF-2024-41) (also referred to as the MCAI), to 
correct an unsafe condition 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), CL-600-2D24 
(Regional Jet Series 900), and CL-600-2E25 (Regional Jet Series 1000) 
airplanes. The MCAI states that new or more restrictive airworthiness 
limitations have been developed.
    The FAA is proposing this AD to address reduced structural 
integrity and reduced controllability of the airplane. You may examine 
the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-
2261.

Other Relevant Rulemaking

    The FAA issued the following ADs that are related to this proposed 
AD:
     AD 2023-06-06, Amendment 39-22392 (88 FR 17682, March 24, 
2023); corrected April 12, 2023 (88 FR 21900) (AD 2023-06-06), which 
applies to all MHI RJ Aviation ULC Model CL-600-2C10 (Regional Jet 
Series 700, 701 & 702) airplanes, Model CL-600-2C11 (Regional Jet 
Series 550) airplanes, Model CL-600-2D15 (Regional Jet Series 705) 
airplanes, Model CL-600-2D24 (Regional Jet Series 900) airplanes, and 
Model C-600-2E25 (Regional Jet Series 1000) airplanes. AD 2023-06-06 
requires revising the existing maintenance or inspection program, as 
applicable, to incorporate two aircraft maintenance manual (AMM) tasks.
     AD 2023-09-02, Amendment 39-22425 (88 FR 32625, May 22, 
2023) (AD 2023-09-02), which applies to all MHI RJ Aviation ULC Model 
CL-600-2B19 (Regional Jet Series 100 & 440), 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. AD 2023-09-
02 requires revising the existing maintenance or inspection program, as 
applicable, to incorporate new or more restrictive AMM and 
certification maintenance requirement (CMR) tasks.
     AD 2023-24-03, Amendment 39-22619 (88 FR 87331, December 
18, 2023) (AD 2023-24-03), which applies to all MHI RJ Aviation ULC 
Model CL-600-2B19 (Regional Jet Series 100 & 440), 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. AD 2023-24-03 requires revising the existing maintenance or 
inspection program, as applicable, to incorporate new or more 
restrictive AMM and CMR tasks.
     AD 2025-11-11, Amendment 39-23057 (90 FR 24315, June 10, 
2025) (AD 2025-11-11), which applies to all 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. AD 2025-11-11 requires revising the existing 
maintenance or inspection program, as applicable, to incorporate new or 
more restrictive AMM tasks.
    Accomplishing the actions required by this proposed AD terminates 
the corresponding requirements of paragraph (h) of AD 2023-09-02 and 
paragraph (h) of AD 2023-24-03 for the AMM tasks identified in the 
material referenced in Transport Canada AD CF-2024-41 only.

[[Page 40782]]

    Accomplishing the actions required by this AD terminates all 
requirements of AD 2023-06-06 and AD 2025-11-11.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed Transport Canada AD CF-2024-41, 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-2024-41 described previously, as incorporated by 
reference. Any differences with Transport Canada AD CF-2024-41 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) and 
Critical Design Configuration Control Limitations (CDCCLs). Compliance 
with these actions and CDCCLs 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 (l)(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-2024-41 by reference 
in the FAA final rule. This proposed AD would, therefore, require 
compliance with Transport Canada AD CF-2024-41 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-2024-41 for compliance will be available at 
regulations.gov by searching for and locating Docket No. FAA-2025-2261 
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), intervals, or CDCCLs may be used unless the actions, 
intervals, and CDCCLs 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, Intervals, and CDCCLs'' paragraph that does not specifically 
refer to AMOCs, but operators may still request an AMOC to use an 
alternative action, interval, or CDCCL.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 600 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 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.

[[Page 40783]]

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-2025-2261; Project Identifier MCAI-2024-00717-
T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by October 6, 2025.

(b) Affected ADs

    This AD affects the ADs specified in paragraphs (b)(1) through 
(4) of this AD.
    (1) AD 2023-06-06, Amendment 39-22392 (88 FR 17682, March 24, 
2023); corrected April 12, 2023 (88 FR 21900) (AD 2023-06-06).
    (2) AD 2023-09-02, Amendment 39-22425 (88 FR 32625, May 22, 
2023) (AD 2023-09-02).
    (3) AD 2023-24-03, Amendment 39-22619 (88 FR 87331, December 18, 
2023) (AD 2023-24-03).
    (4) AD 2025-11-11, Amendment 39-23057 (90 FR 24315, June 10, 
2025) (AD 2025-11-11).

(c) Applicability

    This AD applies to all MHI RJ Aviation ULC (Type Certificate 
Previously Held by Bombardier, Inc.) airplanes, certificated in any 
category, identified in paragraphs (c)(1) through (5) of this AD.
    (1) Model CL-600-2C10 (Regional Jet Series 700, 701, and 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.
    (5) Model CL-600-2E25 (Regional Jet Series 1000) 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 reduced structural integrity and reduced 
controllability of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Maintenance or Inspection Program Revision

    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-2024-41, dated December 5, 
2024 (Transport Canada AD CF-2024-41).

(h) Exception to Transport Canada AD CF-2024-41

    (1) Where Transport Canada AD CF-2024-41 refers to its effective 
date, this AD requires using the effective date of this AD.
    (2) Where Transport Canada AD CF-2024-41 specifies to ``complete 
the new or more restrictive limitations contained in the MHIRJ MRM 
CSP B-053 Part 2, revision 27, dated 15 September 2023, as 
applicable to the aeroplane model and configuration within the 
thresholds and repeat intervals or discard time identified within 
the tasks'', this AD requires replacing that text with ``revise the 
existing maintenance or inspection program, as applicable, by 
incorporating the information specified in MHIRJ MRM CSP B-053 Part 
2, Revision 27, dated September 15, 2023, except when incorporating 
Appendix A2, only incorporate the AMM tasks, including the interval 
limitation, specified in the limitations table in Appendix A2''.
    (3) The initial compliance time for doing the tasks specified in 
the ``Corrective Actions'' section of Transport Canada AD CF-2024-41 
is at the applicable time specified in paragraph (h)(3)(i) or (ii) 
of this AD.
    (i) For tasks that have ``thresholds'' and ``discard times'' 
specified: The initial compliance time is at the applicable 
``thresholds'' and ``discard times'' as specified in the material 
referenced in Transport Canada AD CF-2024-41, or within 30 days 
after the effective date of this AD, whichever occurs later.
    (ii) For tasks that only have ``intervals'' specified: The 
initial compliance time is before the applicable interval limitation 
specified in the material referenced in Transport Canada AD CF-2024-
41 since the date of issuance of the original airworthiness 
certificate or the original export certificate of airworthiness, or 
within 30 days after the effective date of this AD, whichever occurs 
later.

(i) Provisions for Alternative Actions, Intervals, and Critical Design 
Configuration Control Limitations (CDCCLs)

    After the existing maintenance or inspection program has been 
revised as required by paragraph (g) of this AD, no alternative 
actions (e.g., inspections), intervals, and CDCCLs are allowed 
unless they are approved as specified in the provisions of the 
``Corrective Actions'' section of Transport Canada AD CF-2024-41.

(j) Terminating Action for Certain Tasks Required by Other ADs

    Accomplishing the actions required by this AD terminates the 
corresponding requirements of paragraph (h) of AD 2023-09-02 and 
paragraph (h) of AD 2023-24-03 for the AMM tasks identified in the 
material referenced in Transport Canada AD CF-2024-41 only.

(k) Terminating Action for AD 2023-06-06 and AD 2025-11-11

    Accomplishing the actions required by this AD terminates all 
requirements of AD 2023-06-06 and AD 2025-11-11.

(l) Additional AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
International Validation Branch, 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 (m) 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.

(m) 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].

(n) 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-2024-41, dated December 5, 2024.
    (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

[[Page 40784]]

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 August 18, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2025-15998 Filed 8-20-25; 8:45 am]
BILLING CODE 4910-13-P