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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2024-0026; Project Identifier MCAI-2023-00776-T]
          - RIN 2120-AA64

# 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-600-2E25 (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, as specified in a Transport Canada AD, which is proposed for incorporation by reference (IBR). 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 February 26, 2024.

# 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.                    
      -  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-2024-0026; 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 that is proposed for IBR in this NPRM, 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;                          website                          tc.canada.ca/en/aviation.                          It is also available at                          regulations.gov                          under Docket No. FAA-2024-0026.                    
      - You may view this service information 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; telephone 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 proposal. Send your comments to an address listed under                     **ADDRESSES**                    . Include “Docket No. FAA-2024-0026; Project Identifier MCAI-2023-00776-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; telephone 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

Transport Canada, which is the aviation authority for Canada, has issued AD CF-2023-43, dated June 21, 2023 (Transport Canada AD CF-2023-43) (also referred to as the MCAI), to correct an unsafe condition for all MHI RJ Aviation ULC Model 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 prevent potential fatigue cracking and                           ( print page 1850)                        damage in principal structural elements. The unsafe condition, if not addressed, could result in reduced structural integrity of the airplane. You may examine the MCAI in the AD docket at                     *regulations.gov*                     under Docket No. FAA-2024-0026.                

## Related Service Information Under 1 CFR Part 51

                    The FAA reviewed Transport Canada AD CF-2023-43, which specifies new or more restrictive airworthiness limitations for airplane structures and a safe life limit. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in                     **ADDRESSES**                    .                

## FAA's Determination

This product has been approved by the aviation authority of another country and is approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, it 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-2023-43 described previously, as incorporated by reference. Any differences with Transport Canada AD CF-2023-43 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). Compliance with these actions 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 (j)(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-2023-43 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with Transport Canada AD CF-2023-43 through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Service information required by Transport Canada AD CF-2023-43 for compliance will be available at                     *regulations.gov*                     by searching for and locating Docket No. FAA-2024-0026 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) or intervals may be used unless the actions and intervals are approved as an AMOC in accordance with the procedures specified in the AMOC paragraph under “Additional AD Provisions.” This new format includes a “New Provisions for Alternative Actions and Intervals” paragraph that does not specifically refer to AMOCs, but operators may still request an AMOC to use an alternative action or interval.                

## Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 5 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 × $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,                           ( print page 1851)                        on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.                

# 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

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

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

§ 39.13

2. The FAA amends § 39.13 by adding the following new airworthiness directive: 

**MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier, Inc.):**                         Docket No. FAA-2024-0026; Project Identifier MCAI-2023-00776-T.                    

## (a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by February 26, 2024.

## (b) Affected ADs

None.

## (c) Applicability

This AD applies to all MHI RJ Aviation ULC (Type Certificate previously held by Bombardier, Inc.) Model CL-600-2E25 (Regional Jet Series 1000) airplanes, certificated in any category.

## (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 prevent potential fatigue cracking and damage in principal structural elements. The unsafe condition, if not addressed, could result in reduced structural integrity 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-2023-43, dated June 21, 2023 (Transport Canada AD CF-2023-43).

## (h) Exceptions to Transport Canada AD CF-2023-43

(1) Where Transport Canada AD CF-2023-43 refers to its effective date, this AD requires using the effective date of this AD.

(2) Where paragraph 1. of Transport Canada AD CF-2023-43 specifies to “incorporate the new and revised tasks identified in Table 1 below, in the appropriate chapter within Section 2 and Section 3 of the MRM CSP B-053 Part 2 manual,” this AD requires replacing those words with “revise the existing maintenance or inspection program, as applicable, by incorporating the new and revised tasks identified in Table 1.”

(3) The initial compliance time for doing the tasks specified in paragraph 1. of Transport Canada AD CF-2023-43 is at the applicable “thresholds” and “discard times” as specified in the service information referenced in paragraph 1. of Transport Canada AD CF-2023-43, or within 60 days after the effective date of this AD, whichever occurs later.

(4) This AD does not adopt paragraph 2. of Transport Canada AD CF-2023-43.

## (i) Provisions for Alternative Actions and Intervals

                        After the existing maintenance or inspection program has been revised as required by paragraph (g) of this AD, no alternative actions (                        *e.g.,*                         inspections) and intervals are allowed unless they are approved as specified in the provisions of the “Corrective Actions” section of Transport Canada AD CF-2023-43.                    

## (j) 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, mail it to the address identified in paragraph (k) of this AD. Information may be emailed to                         *9-AVS-NYACO-COS@faa.gov.*                         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.                    

## (k) Additional Information

                        For more information about this AD, contact Fatin Saumik, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; email                         *9-avs-nyaco-cos@faa.gov.*

## (l) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) You must use this service information as applicable to do the actions required by this AD, unless this AD specifies otherwise.

(i) Transport Canada AD CF-2023-43, dated June 21, 2023.

(ii) [Reserved]

                        (3) For Transport Canada AD CF-2023-43, 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;*                         website                         *tc.canada.ca/en/aviation.*

(4) You may view this service information 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 January 5, 2024.

Victor Wicklund,

Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.

[FR Doc. 2024-00343 Filed 1-10-24; 8:45 am]

BILLING CODE 4910-13-P