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 Department of Transportation Federal Aviation Administration 14 CFR Part 39
[Docket No. FAA-2025-0199; Project Identifier MCAI-2024-00332-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 certain Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. This proposed AD was prompted by certification testing that found that environmental control system (ECS) ducts manufactured using a certain material failed the flammability test requirements established for compliance. This proposed AD would require inspecting the affected ECS ducts and, as applicable, installing a fire-resistant sleeve assembly over any non-compliant ECS duct, and prohibit the installation of ECS ducts as replacement parts under certain conditions, 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 March 31, 2025.
 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 
                        ( print page 9527)
                        p.m., Monday through Friday, except Federal holidays. *AD Docket:*
                         You may examine the AD docket at 
                        *regulations.gov*
                         under Docket No. FAA-2025-0199; 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 identified in this proposed AD, 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-2025-0199.
                    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.
 FOR FURTHER INFORMATION CONTACT: Brenda Buitrago Perez, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone 516-228-7368; email 
                        *brenda.l.buitrago.perez@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 the 
                    **ADDRESSES**
                     section. Include “Docket No. FAA-2025-0199; Project Identifier MCAI-2024-00332-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 Brenda Buitrago Perez, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone 516-228-7368; email 
                    *brenda.l.buitrago.perez@faa.gov.*
                     Any commentary that the FAA receives that 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 Transport Canada AD CF-2024-21, dated June 20, 2024 (Transport Canada AD CF-2024-21) (also referred to as the MCAI), to correct an unsafe condition for certain Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. The MCAI states that ECS ducts, located on forward and aft cargo compartment ceiling panels, having part numbers (P/Ns) D761189-105, D761189-501, and D762232-509, have been manufactured using material APF1180-7781, which replaced discontinued legacy material Solvay L591PG-7781. The material change to APF1180-7781 was done without changing the ECS duct part number. Subsequent certification testing of the ECS ducts made using material APF1180-7781 failed flammability test requirements. These noncompliant ECS ducts may have been installed on certain affected airplanes during production. Noncompliant ECS ducts could result in the inability to contain a fire within the cargo compartment, which could result in an uncontrolled fire. The FAA is proposing this AD to address the unsafe condition on these products. You may examine the MCAI in the AD docket at 
                    *regulations.gov*
                     under Docket No. FAA-2025-0199. Material Incorporated by Reference Under 1 CFR Part 51 Transport Canada AD CF-2024-21 specifies procedures for inspecting to determine the lot numbers of affected ECS ducts and installing a fire-resistant sleeve assembly over any non-compliant ECS duct. Transport Canada AD CF-2024-21 also prohibits the installation of ECS ducts as replacement parts under certain conditions. 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. 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 accomplishing the actions specified in Transport Canada AD CF-2024-21 described previously, except for any differences identified as exceptions in the regulatory text 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-2024-21 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with Transport Canada AD CF-2024-21 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Material required by Transport Canada AD CF-2024-21 for compliance will be available at 
                    *regulations.gov*
                     under Docket No. FAA-2025-0199 after the FAA final rule is published.
                    ( print page 9528) Costs of Compliance The FAA estimates that this AD, if adopted as proposed, would affect 11 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD: Estimated Costs for Required Actions
Labor cost
Parts cost
Cost per
                             product
Cost on U.S.
                             operators12 work-hours × $85 per hour = $1,020
$0
$1,020
$11,220
 The FAA estimates the following costs to do any necessary on-condition actions 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 these on-condition actions: Estimated Costs of On-Condition Actions
Labor cost
Parts cost
Cost per product2 work-hours × $85 per hour = $170
(*)
* $170* The FAA has received no definitive data on which to base the cost estimates for the parts cost specified in this proposed AD.
 The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some or all of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected operators. 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 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, 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: **Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.):**
                         Docket No. FAA-2025-0199; Project Identifier MCAI-2024-00332-T. (a) Comments Due Date The FAA must receive comments on this airworthiness directive (AD) by March 31, 2025. (b) Affected ADs None. (c) Applicability This AD applies to Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500-1A11 airplanes, certificated in any category, as identified in Transport Canada AD CF-2024-21, dated June 20, 2024 (Transport Canada AD CF-2024-21). (d) Subject Air Transport Association (ATA) of America Code 25, Equipment/furnishings. (e) Unsafe Condition This AD was prompted by certification testing that found that environmental control system (ECS) ducts manufactured using material APF1180-7781 failed the flammability test requirements established for compliance. The FAA is issuing this AD to address noncompliant ECS ducts that could cause an inability to contain a fire within the cargo compartment. The unsafe condition, if not addressed, could result in an uncontrolled fire. (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-2024-21. (h) Exception to Transport Canada AD CF-2024-21 (1) Where Transport Canada AD CF-2024-21 refers to its effective date, this AD requires using the effective date of this AD. (2) Where Transport Canada AD CF-2024-21 refers to hours air time, this AD requires using flight hours.
                        ( print page 9529) (i) Additional AD Provisions The following provisions also apply to this AD: (1) 
                        *Alternative Methods of Compliance (AMOCs):*
                         The Manager, AIR-520, Continued Operational Safety 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 Continued Operational Safety 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 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, AIR-520, Continued Operational Safety Branch, FAA; or Transport Canada; or Airbus Canada Limited Partnership's Transport Canada Design Approval Organization (DAO). If approved by the DAO, the approval must include the DAO-authorized signature. (3) 
                        *Required for Compliance (RC):*
                         Except as required by paragraph (i)(2) of this AD, if any material contains procedures or tests that are identified as RC, those procedures and tests must be done to comply with this AD; any procedures or tests that are not identified as RC are recommended. Those procedures and tests that are not identified as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC, provided the procedures and tests identified as RC can be done and the airplane can be put back in an airworthy condition. Any substitutions or changes to procedures or tests identified as RC require approval of an AMOC. (j) Additional Information For more information about this AD, contact Brenda Buitrago Perez, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone 516-228-7368; email 
                        *brenda.l.buitrago.perez@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) Transport Canada AD CF-2024-21, dated June 20, 2024. (ii) [Reserved] (3) 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 
                        *TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca;*
                         website 
                        *tc.canada.ca/en/aviation.* (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 February 6, 2025. John P. Piccola, Jr., Director, Integrated Certificate Management Division, Aircraft Certification Service.


[FR Doc. 2025-02505 Filed 2-12-25; 8:45 am] BILLING CODE 4910-13-P