2025-24-11: Auxiliary Power

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2025-24-11 Bombardier, Inc.: Amendment 39-23208; Docket No. FAA-2025-1728; Project Identifier MCAI-2025-00076-T. (a) Effective Date This airworthiness directive (AD) is effective January 16, 2026. (b) Affected ADs None. (c) Applicability This AD applies to all Bombardier, Inc., Model CL-600-2A12 (601) and CL-600-2B16 (601-3A, 601-3R, and 604 Variants) airplanes, certificated in any category. (d) Subject Air Transport Association (ATA) of America Code 49, Auxiliary Power (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 an accumulation of fuel in the auxiliary power unit (APU) muffler caused by a drainage block in the muffler. This condition if not corrected, could lead to an accumulation of fuel in the muffler being ignited by the high-temperature exhaust gases in the muffler, and could subsequently lead to an uncontrolled fire in the APU bay. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Maintenance or Inspection Program Revision Within 90 days after the effective date of this AD, revise the existing maintenance or inspection program, as applicable, to incorporate the information specified in the applicable tasks identified in figure 1 to paragraph (g) of this AD. The initial compliance time for doing the tasks is at the time specified in the applicable tasks identified in figure 1 to paragraph (g) of this AD, or within 90 days after the effective date of this AD, whichever occurs later. Figure 1 to Paragraph (g)-Temporary Revisions and Tasks ER12DE25.000 Note 1 to figure 1 to paragraph (g): The asterisk (or "one star") with the last three digits of the task numbers listed in table 1 to paragraph (g) of this AD indicates that the task is an airworthiness limitation task. (h) No Alternative Actions or 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) 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 (i)(1) of this AD. (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 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 . Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the 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'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 Joseph Catanzaro, 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) Bombardier Temporary Revision No. 5-2-6, dated June 28, 2024. (ii) Bombardier Temporary Revision No. 5-2-30, dated June 28, 2024. (iii) Bombardier Temporary Revision No. 5-2-74, dated June 28, 2024. (iv) Bombardier Temporary Revision No. TR 5-271, dated September 30, 2024. (v) Bombardier Temporary Revision No. TR 5-285, dated September 30, 2024. (3) For Bombardier 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 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 24, 2025. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2025-22630 Filed 12-11-25; 8:45 am]BILLING CODE 4910-13-P