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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2023-1496; Project Identifier MCAI-2022-01059-T; Amendment 39-22619; AD 2023-24-03]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Final rule.

# SUMMARY:

The FAA is adopting a new airworthiness directive (AD) 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. This AD was prompted by a determination that aircraft maintenance manual (AMM) tasks and certification maintenance requirement (CMR) tasks are necessary. This AD requires revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive AMM and CMR tasks. The FAA is issuing this AD to address the unsafe condition on these products.

# DATES:

This AD is effective January 22, 2024.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of January 22, 2024.

# ADDRESSES:

*AD Docket:*                         You may examine the AD docket at                         *regulations.gov*                         under Docket No. FAA-2023-1496; or in person at Docket Operations between 9 a.m. and                               ( print page 87332)                            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 address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.                    

*Material Incorporated by Reference:*
      - For service information identified in this final rule, contact MHI RJ Aviation Group, Customer Response Center, 3655 Ave. des Grandes-Tourelles, Suite 110, Boisbriand, Québec J7H 0E2 Canada; North America toll-free telephone 833-990-7272 or direct-dial telephone 450-990-7272; fax 514-855-8501; email thd.crj@mhirj.com;                          website                          mhirj.com. 
      - 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. It is also available at regulations.gov                          under Docket No. FAA-2023-1496.                    

# FOR FURTHER INFORMATION CONTACT:

                        Elizabeth Dowling, 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:

## Background

                    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply 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. The NPRM published in the                     **Federal Register**                     on July 19, 2023 (88 FR 46118). The NPRM was prompted by AD CF-2022-42, dated August 8, 2022, issued by Transport Canada, which is the aviation authority for Canada (referred to after this as the MCAI). The MCAI states that operators have reported frequent flight interruptions and high lavatory smoke detector removal rates due to the frequent testing of the smoke detector self-test switch by the flight crew using unsuitable objects. The MCAI also states there is a potential dormant failure of the lavatory smoke detector if the self-test switch check is not performed in accordance with revised procedures.                

In the NPRM, the FAA proposed to require revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive AMM and CMR tasks. The FAA is issuing this AD to address a potential dormant failure of the lavatory smoke detector if the self-test switch check is not performed in accordance with revised AMM or CMR tasks. If these maintenance task changes are not implemented, and in combination with a fire in the lavatory, this may lead to a delay in the reaction time to address smoke/fire in the lavatory.

                    You may examine the MCAI in the AD docket at                     *regulations.gov*                     under Docket No. FAA-2023-1496.                

## Discussion of Final Airworthiness Directive

## Comments

The FAA received a comment from Air Line Pilots Association, International, who supported the NPRM without change.

The FAA received an additional comment from MHI RJ Aviation. The following presents the comment received on the NPRM and the FAA's response.

## Request To Identify Corrected Revisions

MHI RJ requested that the corrected revisions for Aircraft Maintenance Manual (AMM) Tasks 26-16-00-710-804-A01 and 26-16-00-710-803-A01 be identified as found in AMM CSP B-001, Revision 71. The commenter stated that the Maintenance Task Card Manual (MTCM) Task Card updates were also implemented in AMM Tasks 26-16-00-710-804-A01 and 26-16-00-710-803-A01, but references to the AMM tasks in the proposed AD do not indicate the corrected revision.

The FAA agrees with the requested change since it provides a means for operators to ensure the revised maintenance tasks are included in the AMM revision they are using. Therefore, figure 1 to paragraph (h) of this AD has been changed to specify AMM Rev 68 or later approved revisions.

## Conclusion

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 reviewed the relevant data, considered the comment received, and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on this product. Except for minor editorial changes, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator.

## Related Service Information Under 1 CFR Part 51

                    The FAA reviewed Bombardier Temporary Revision 2A-75, dated May 28, 2020. This service information specifies new or more restrictive CMR tasks. 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 the                     **ADDRESSES**                     section.                

## Costs of Compliance

The FAA estimates that this AD affects 1,024 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:

The FAA has determined that revising the 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

                    This AD will not have federalism implications under Executive Order                           ( print page 87333)                        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,

(2) Will not affect intrastate aviation in Alaska, and

(3) Will not have a significant economic impact, positive or negative, 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 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

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

**2023-24-03 MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier, Inc.):**                             Amendment 39-22619; Docket No. FAA-2023-1496; Project Identifier MCAI-2022-01059-T.                        

## (a) Effective Date

This airworthiness directive (AD) is effective January 22, 2024.

## (b) Affected ADs

None.

## (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 26, Fire Protection.

## (e) Reason

This AD was prompted by a determination that new or more restrictive aircraft maintenance manual (AMM) tasks and certification maintenance requirement (CMR) tasks are necessary. The FAA is issuing this AD to address a potential dormant failure of the lavatory smoke detector if the self-test switch check is not performed in accordance with the revised AMM or CMR tasks. If these maintenance task changes are not implemented, and in combination with a fire in the lavatory, this may lead to a delay in the reaction time to address smoke/fire in the lavatory.

## (f) Compliance

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

## (g) Maintenance or Inspection Program Revision for Model CL-600-2B19 (Regional Jet Series 100 & 440) Airplanes

For Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes: Within 60 days after the effective date of this AD, revise the existing maintenance or inspection program, as applicable, to incorporate the information specified in Bombardier Temporary Revision 2A-75, dated May 28, 2020. The initial compliance time is within 12 months after the effective date of this AD.

## (h) Maintenance or Inspection Program Revision for Other Airplanes

For airplanes identified in paragraphs (c)(2) through (6) of this AD: Within 60 days after the effective date of this AD, revise the existing maintenance or inspection program, as applicable, to incorporate the information specified in Figure 1 to paragraph (h) of this AD. The initial compliance time for doing the tasks is within 12 months after the effective date of this AD.

##                             Figure 1 to Paragraph (h)—                            *AMM task for an operational check of the lavatory smoke detector (forward and aft)*

## (i) No Alternative Actions or Intervals

                            After the existing maintenance or inspection program has been revised as required by paragraph (g) or (h) of this AD, no alternative actions (                            *e.g.,*                             inspections) or intervals may be used unless the actions, and intervals are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (j)(1) of this AD.                        

## (j) Other FAA 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 certification office, send it to ATTN: Program Manager, Continuing Operational Safety, FAA, International Validation Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300. 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

                            (1) Refer to Transport Canada AD CF-2022-42, dated August 8, 2022, for related information. This Transport Canada AD may be found in the AD docket at                             *regulations.gov*                             under Docket No. FAA-2023-1496.                        

                            (2) For more information about this AD, contact Elizabeth Dowling, 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                                   ( print page 87334)                                (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 to do the actions required by this AD, unless this AD specifies otherwise.

(i) Bombardier Temporary Revision 2A-75, dated May 28, 2020.

(ii) [Reserved]

                            (3) For service information identified in this AD, contact MHI RJ Aviation Group, Customer Response Center, 3655 Ave. des Grandes-Tourelles, Suite 110, Boisbriand, Québec J7H 0E2 Canada; North America toll-free telephone 833-990-7272 or direct-dial telephone 450-990-7272; fax 514-855-8501; email                             *thd.crj@mhirj.com;*                             website                             *mhirj.com.*

(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 November 29, 2023.

Victor Wicklund,

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

[FR Doc. 2023-27680 Filed 12-15-23; 8:45 am]

BILLING CODE 4910-13-P