Comments Invited The FAA invites you to send any written data, views, or arguments about this final rule. Send your comments using a method listed under the ADDRESSES section. Include "Docket No. FAA-2026-1327; Project Identifier MCAI-2025-00042-T" at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, 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 final rule 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 final rule. 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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to William Reisenauer, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7301; email: william.e.reisenauer@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 The FAA issued AD 2025-14-51, dated July 25, 2025 (AD 2025-14-51), to address an unsafe condition on certain Bombardier Inc. Model BD-700-1A10 and BD-700-1A11 airplanes. The FAA sent AD 2025-14-51 to all known U.S. owners and operators of these airplanes. AD 2025-14-51 requires installing locking features on the applicable network interfaces. AD 2025-14-51 was prompted by Transport Canada AD CF-2025-03, dated January 15, 2025 (Transport Canada AD CF-2025-03) (also referred to as the MCAI), issued by Transport Canada, which is the aviation authority for Canada, to correct an unsafe condition on certain serial-numbered Bombardier Inc. Model BD-700-1A10 and BD-700-1A11 airplanes. The MCAI specifies installing locking features on certain network interfaces to prevent unapproved access to these network interfaces. This AD was prompted by discrepancies in the locking features on certain network interfaces. The FAA is issuing this AD to address these discrepancies, which could result in unapproved access to these network interfaces. You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2026-1327. FAA's Determination 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 described above. The FAA is issuing this AD after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design. AD Requirements This AD requires installing locking features on the applicable network interfaces. Justification for Immediate Adoption and Determination of the Effective Date Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C. 551 et seq. ) authorizes agencies to dispense with notice and comment procedures for rules when the agency, for "good cause," finds that those procedures are "impracticable, unnecessary, or contrary to the public interest." Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance. Further, section 553(d) of the APA authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause. An unsafe condition exists that required the immediate adoption of AD 2025-14-51, issued on July 10, 2025, to all known U.S. owners and operators of these airplanes. The FAA found that the risk to the flying public justified forgoing notice and comment prior to adoption of this rule because the subject of this AD concerns unauthorized access to network interfaces of the aircraft. Providing an opportunity to comment before operators have complied with this action would be detrimental to transportation security. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to 14 CFR 39.13 to make it effective to all persons. Given the significance of the risk presented by this unsafe condition, it must be immediately addressed. Accordingly, notice and opportunity for prior public comment are impracticable and contrary to the public interest pursuant to 5 U.S.C. 553(b). In addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for making this amendment effective in less than 30 days, for the same reasons the FAA found good cause to forgo notice and comment. Regulatory Flexibility Act The requirements of the Regulatory Flexibility Act (RFA) do not apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and comment. Because the FAA has determined that it has good cause to adopt this rule without notice and comment, RFA analysis is not required. Costs of Compliance The FAA estimates that this AD affects 1,313 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: Estimated Costs of Required Actions Labor cost Parts cost Cost per product Cost on U.S. operators 1 work-hour × $85 per hour = $85 $802 $887 $1,164,631 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, and (2) Will not affect intrastate aviation in Alaska. 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: 2025-14-51 Bombardier Inc.: Amendment 39-23263; Docket No. FAA-2026-1327; Project Identifier MCAI-2025-00042-T. (a) Effective Date The FAA issued Airworthiness Directive (AD) 2025-14-51 on July 10, 2025, directly to affected owners and operators. As a result of such actual notice, AD 2025-14-51 was effective for those owners and operators on the date it was received. This AD contains the same requirements as AD 2025-14-51 and, for those who did not receive actual notice, is effective on March 4, 2026. (b) Affected ADs None. (c) Applicability This AD applies to the Bombardier Inc. airplanes, certificated in any category, listed in paragraphs (c)(1) and (2) of this AD. (1) Model BD-700-1A10 airplanes, serial numbers 9381, 9432 through 9861 inclusive, 9863 through 9878 inclusive, and 60001 through 61999 inclusive. (2) Model BD-700-1A11 airplanes, serial numbers 9386, 9401, 9445 through 9862 inclusive, 9868 through 9879 inclusive, and 60007 through 61999 inclusive. (d) Subject Air Transport Association (ATA) of America Code 31, Indicating/Recording System. (e) Unsafe Condition This AD was prompted by discrepancies in the locking features on certain network interfaces. The FAA is issuing this AD to address these discrepancies, which could result in unapproved access to these network interfaces. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Action Within 6 months after the effective date of this AD, install locking features on the applicable network interfaces using a method approved by the Manager, International Validation Branch, FAA. (h) Credit for Previous Actions This paragraph provides credit for the actions required by paragraph (g) of this AD, if those actions were performed before the effective date of this AD using Bombardier Service Bulletin 700-46-5008, dated July 20, 2022; Bombardier Service Bulletin 700-46-6008, dated July 20, 2022; Bombardier Service Bulletin 700-46-5504, dated July 20, 2022; Bombardier Service Bulletin 700-46-5504, Revision 01, dated August 22, 2024; Bombardier Service Bulletin 700-46-6504, dated July 20, 2022; or Bombardier Service Bulletin 700-46-6504, Revision 01, dated August 22, 2024. (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)(1) 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, 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. (j) Additional Information (1) For more information about this AD, contact William Reisenauer, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7301; email: william.e.reisenauer@faa.gov . (2) For Bombardier Inc. material identified in this AD that is not incorporated by reference, 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 . (k) Material Incorporated by Reference None. Issued on February 12, 2026. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.