Background The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain Bombardier, Inc., Model BD-700-2A12 airplanes. The NPRM published in the Federal Register on May 22, 2024 (89 FR 44933). The NPRM was prompted by AD CF-2023-61, dated August 16, 2023, issued by Transport Canada, which is the aviation authority for Canada (Transport Canada AD CF-2023-61) (also referred to as the MCAI). The MCAI states that the pivot door pressure seals on the thrust reverser fixed structure were found disbonded or missing on several airplanes. In the NPRM, the FAA proposed to require inspecting the pivot door pressure seals and accomplishing applicable corrective actions. The FAA also proposed to require a functional test of the thrust reversers. The FAA is issuing this AD to address the pivot door pressure seals on the thrust reverser fixed structure. The unsafe condition, if not addressed, could result in engine thrust loss due to flow path overboard leakage during forward thrust operation and reduce airplane performance during one-engine inoperative conditions in climb margin and ceiling altitude. You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2024-1468. Discussion of Final Airworthiness Directive Comments The FAA received no comments on the NPRM or on the determination of the cost to the public. 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 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. Material Incorporated by Reference Under 1 CFR Part 51 The FAA reviewed Bombardier Service Bulletin 700-78-7501, Revision 01, dated July 13, 2023. This material specifies procedures for one-time general visual inspection for discrepant (missing, damaged, or disbonded) thrust reverser pivoting door pressure seals, a bonding check of the pivoting door seals, and repair or replacement of discrepant seals. This material also specifies procedure for performing a functional test of the thrust reverser. 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. Costs of Compliance The FAA estimates that this AD affects 53 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: Estimated Costs Labor cost Parts cost Cost per product Cost on U.S. operators 6 work-hours × $85 per hour = $510 $0 $510 $27,030 The FAA estimates the following costs to do any necessary on-condition action that would be required based on the results of any required actions. The FAA has no way of determining the number of aircraft that might need this on-condition action: On-Condition Costs Labor cost Parts cost Cost per product Up to 24 work-hours × $85 per hour = $2,040 $4,850 Up to $6,890. 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, (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 [Amended] 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2024-18-06 Bombardier, Inc.: Amendment 39-22840; Docket No. FAA-2024-1468; Project Identifier MCAI-2023-00975-T. (a) Effective Date This airworthiness directive (AD) is effective January 23, 2025. (b) Affected ADs None. (c) Applicability This AD applies to Bombardier, Inc., Model BD-700-2A12 airplanes, certificated in any category, serial numbers 70007, 70008, 70010, 70012 through 70047 inclusive, 70049, 70051, 70052, 70053, 70055 through 70077 inclusive, 70079, 70080, 70081, 70083 through 70133 inclusive, 70135, 70136, 70137, 70138, 70142 through 70148 inclusive, 70150, 70152, and 70158. (d) Subject Air Transport Association (ATA) of America Code 78, Engine exhaust. (e) Unsafe Condition This AD was prompted by reports that the pivot door pressure seals on the thrust reverser fixed structure were found disbonded or missing on several airplanes. The FAA is issuing this AD to address the pivot door pressure seals on the thrust reverser fixed structure. The unsafe condition, if not addressed, could result in engine thrust loss due to flow path overboard leakage during forward thrust operation and reduce airplane performance during one-engine inoperative conditions in climb margin and ceiling altitude. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Inspection and Functional Test (1) Within 750 flight hours or 18 months, whichever comes first from the effective date of this AD, perform a general visual inspection for discrepancies (missing, damaged, or disbonding) of the 4 pivot door pressure seals on the thrust reverser door of each engine, and perform a bonding check as applicable, and repair or replace each discrepant seal as applicable, in accordance with Part 2.B of the Accomplishment Instructions of Bombardier Service Bulletin 700-78-7501, Revision 01, dated July 13, 2023. Applicable corrective actions must be done before further flight. (2) Before further flight after accomplishing the actions specified in paragraph (g)(1) of this AD: Perform a functional test of the thrust reverser in accordance with Part 2.C of the Accomplishment Instructions of Bombardier Service Bulletin 700-78-7501, Revision 01, dated July 13, 2023. (h) Credit for Previous Actions This paragraph provides credit for actions required by paragraph (g) of this AD, if those actions were performed before the effective date of this AD using Bombardier Service Bulletin 700-78-7501, dated April 12, 2023. (i) No Reporting Requirement Although the service information referenced in Bombardier Service Bulletin 700-78-7501, Revision 01, dated July 13, 2023, specifies to submit certain information to the manufacturer, this AD does not include that requirement. (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 Bombardier, Inc.'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 Joseph Catanzaro, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; email joseph.catanzaro@faa.gov. (l) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference (IBR) 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) Bombardier Service Bulletin 700-78-7501, Revision 01, dated July 13, 2023. (ii) [Reserved] (3) For Bombardier, Inc., material identified in this AD, contact Bombardier Business Aircraft Customer Response Center, 400 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; telephone 514-855-2999; email ac.yul@aero.bombardier.com; website bombardier.com . (4) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th Street, 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 October 24, 2024. Victor Wicklund, Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.