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Rule

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

A Rule by the Federal Aviation Administration on 03/06/2026

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3. Document Details Published Content - Document Details Agencies Department of Transportation Federal Aviation Administration Agency/Docket Numbers Docket No. FAA-2026-2285 Project Identifier MCAI-2025-01848-T Amendment 39-23278 AD 2026-05-05 CFR 14 CFR 39 Document Citation 91 FR 10961 Document Number 2026-04465 Document Type Rule Pages 10961-10965 (5 pages) Publication Date 03/06/2026 RIN 2120-AA64 Published Content - Document Details

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• Document Details Published Content - Document Details Agencies Department of Transportation Federal Aviation Administration Agency/Docket Numbers Docket No. FAA-2026-2285 Project Identifier MCAI-2025-01848-T Amendment 39-23278 AD 2026-05-05 CFR 14 CFR 39 Document Citation 91 FR 10961 Document Number 2026-04465 Document Type Rule Pages 10961-10965 (5 pages) Publication Date 03/06/2026 RIN 2120-AA64 Published Content - Document Details
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  • AGENCY:
  • ACTION:
  • SUMMARY:
  • DATES:
  • ADDRESSES:
  • FOR FURTHER INFORMATION CONTACT:
  • SUPPLEMENTARY INFORMATION:
  • Comments Invited
  • Confidential Business Information
  • Background
  • Actions Since AD 2023-23-02 Was Issued
  • Other Relevant Rulemaking
  • Explanation of Retained Requirements
  • Material Incorporated by Reference Under 1 CFR Part 51
  • FAA's Determination
  • Requirements of This AD
  • Explanation of Required Compliance Information
  • Justification for Immediate Adoption and Determination of the Effective Date
  • Regulatory Flexibility Act
  • Costs of Compliance
  • Authority for This Rulemaking
  • Regulatory Findings
  • List of Subjects in 14 CFR Part 39
  • The Amendment
  • PART 39—AIRWORTHINESS DIRECTIVES
  • (a) Effective Date
  • (b) Affected ADs
  • (c) Applicability
  • (d) Subject
  • (e) Unsafe Condition
  • (f) Compliance
  • (g) Requirements
  • (h) Exception to Transport Canada AD CF-2025-70
  • (i) Additional AD Provisions
  • (j) Additional Information
  • (k) Material Incorporated by Reference Enhanced Content - Table of Contents

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Department of Transportation

Federal Aviation Administration

1. 14 CFR Part 39
2. [Docket No. FAA-2026-2285; Project Identifier MCAI-2025-01848-T; Amendment 39-23278; AD 2026-05-05]
3. RIN 2120-AA64

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule; request for comments.

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. ( printed 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 TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca. 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: 9-avs-nyaco-cos@faa.gov.

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: 9-avs-nyaco-cos@faa.gov. 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 ( printed 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 ( printed 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:

| Action | Labor cost | Parts cost | Cost per product | Cost on U.S.
operators |
| --- | --- | --- | --- | --- |
| Retained actions from AD 2023-23-02 | Up to 8 work-hours × $85 per hour = $680 | $0 | Up to $680 | Up to $483,480. |
| New actions | Up to 8 work-hours × $85 per hour = $680 | $0 | Up to $680 | Up to $483,480. |

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

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13 [Amended] 2. The FAA amends § 39.13 by:

a. Removing Airworthiness Directive (AD) 2023-23-02, Amendment 39-22604 (88 FR 86574, December 14, 2023); and

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 ( printed 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: AMOC@faa.gov.

(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: 9-avs-nyaco-cos@faa.gov.

(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 TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca. 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 fr.inspection@nara.gov.

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]

BILLING CODE 4910-13-P

Published Document: 2026-04465 (91 FR 10961)