Airworthiness Directives; Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.) Airplanes

<RULE> DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-0215; Project Identifier MCAI-2024-00347-T; Amendment 39-23161; AD 2025-20-08]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.) Airplanes</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA is adopting a new airworthiness directive (AD) for all Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. This AD was prompted by events where the cargo bottle fail caution message was displayed. This AD requires replacing affected low rate discharge (LRD) bottles, inspecting extinguishing discharge lines and tubes, and replacing extinguishing discharge lines and tubes, as applicable, and also prohibits the installation of affected LRD bottles. The FAA is issuing this AD to address the unsafe condition on these products. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This AD is effective December 30, 2025. The Director of the Federal Register approved the incorporation by reference of a certain publications listed in this AD as of December 30, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> <E T="03">AD Docket:</E> You may examine the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-0215; 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 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. <E T="03">Material Incorporated by Reference:</E> • 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 <E T="03">TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca.</E> You may find this material on the Transport Canada website at <E T="03">tc.canada.ca/en/aviation.</E> • 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 <E T="03">regulations.gov</E> under Docket No. FAA-2025-0215. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Fatin Saumik, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7300; email: <E T="03">9-avs-nyaco-cos@faa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Background</HD> The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. The NPRM was published in the <E T="04">Federal Register</E> on March 3, 2025 (90 FR 11033). The NPRM was prompted by AD CF-2024-23, dated June 18, 2024 (Transport Canada AD CF-2024-23) (also referred to as the MCAI), issued by Transport Canada, which is the aviation authority for Canada. The MCAI states there were events where the cargo bottle fail caution message was displayed during flight resulting in diversions. Investigations found the LRD bottle was depleted of extinguishing agent. Further investigation revealed the LRD bottle metering device could be loose allowing extinguishing agent to escape resulting in loss or degraded capability of the cargo extinguishing system. In the NPRM, the FAA proposed to require replacing affected LRD bottles, inspecting extinguishing discharge lines and tubes, and replacing extinguishing discharge lines and tubes, as applicable, and to prohibit the installation of affected LRD bottles, as specified in Transport Canada AD CF-2024-23. The FAA is issuing this AD to address the unsafe condition on these products. You may examine the MCAI in the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-0215. <HD SOURCE="HD1">Discussion of Final Airworthiness Directive</HD> <HD SOURCE="HD1">Comments</HD> The FAA received a comment from Air Line Pilots Association, International (ALPA) who supported the NPRM without change. The FAA received one additional comment from Delta Air Lines. The following presents the comment received on the NPRM and the FAA's response to each comment. <HD SOURCE="HD1">Request for Exception</HD> Delta Air Lines requested an additional exception be added to the proposed AD to correct a typographical error from “LDR” to “LRD” in Transport Canada AD CF-2024-23, Part I, paragraph B. The FAA agrees with this request and added paragraph (h)(4) of this AD accordingly. <HD SOURCE="HD1">Conclusion</HD> 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 reviewed the relevant data, considered any comments 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 these products. Except for minor editorial changes, and any other changes described previously, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator. <HD SOURCE="HD1">Material Incorporated by Reference Under 1 CFR Part 51</HD> The FAA reviewed Transport Canada AD CF-2024-23 which specifies procedures for verifying aircraft technical records to determine if an affected part (any LRD bottle having part number 475086-1, 475124-1 or 475087-1 with certain serial numbers, unless the LRD bottle is marked with an encircled `C' on the LRD bottle label) is installed on the airplane, replacing affected LRD bottles, and replacing extinguishing discharge lines and tubes, as applicable. Transport Canada AD CF-2024-23 also prohibits the installation of affected parts. The detailed visual inspections of the discharge lines and tubes, in multiple compartments, include checking discharge heads and distribution tubes for signs of residue and corrosion. 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 <E T="02">ADDRESSES</E> section. <HD SOURCE="HD1">Costs of Compliance</HD> The FAA estimates this AD affects 74 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: <GPOTABLE COLS="4" OPTS="L2,i1" CDEF="s50,12C,12C,12C"> <TTITLE>Estimated Costs for Required Actions</TTITLE> <CHED H="1">Labor cost</CHED> <CHED H="1">Parts cost</CHED> <CHED H="1"> Cost per product </CHED> <CHED H="1">Cost on U.S. operators</CHED> <ROW> <ENT I="01">16 work-hours × $85 per hour = $1,360</ENT> <ENT>$0</ENT> <ENT>$1,360</ENT> <ENT>$100,640</ENT> </ROW> </GPOTABLE> <GPOTABLE COLS="3" OPTS="L2,i1" CDEF="s75,r50,r50"> <TTITLE>Estimated Costs of On-Condition Actions</TTITLE> <CHED H="1">Labor cost</CHED> <CHED H="1">Parts cost</CHED> <ENT I="01">10 work-hours × $85 per hour = $850</ENT> <ENT>Up to $17,368</ENT> <ENT>Up to $18,218.</ENT> </ROW> </GPOTABLE> The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some or all of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected operators. <HD SOURCE="HD1">Authority for This Rulemaking</HD> 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. <HD SOURCE="HD1">Regulatory Findings</HD> 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. <LSTSUB> <HD SOURCE="HED">List of Subjects in 14 CFR Part 39</HD> Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. </LSTSUB> <HD SOURCE="HD1">The Amendment</HD> Accordingly, under the authority delegated to me by the ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 17k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━