AD 2026-03549

[Federal Register Volume 91, Number 35 (Monday, February 23, 2026)] [Proposed Rules] [Pages 8390-8393] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 2026-03549]

======================================================================== Proposed Rules Federal Register ________________________________________________________________________ This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules. ========================================================================

Federal Register / Vol. 91, No. 35 / Monday, February 23, 2026 / Proposed Rules

[[Page 8390]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2026-1336; Project Identifier MCAI-2025-00254-T] RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD) 2025-06-01, which applies to all Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. AD 2025-06-01 requires revising the existing airplane flight manual (AFM) to incorporate the procedures for the flightcrew to manually isolate the opposite functional engine in the event of an engine bleed duct large leak condition. Since the FAA issued AD 2025-06-01, an electronic engine control (EEC) software update has been developed to address the unsafe condition. This proposed AD would continue to require the actions in AD 2025-06-01 and would require installing a certain EEC software update on both engines. This proposed AD would also remove airplanes from the applicability. 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 April 9, 2026.

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 p.m., Monday through Friday, except Federal holidays. AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2026-1336; 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 [email protected]. You may find this material on the Transport Canada website at tc.canada.ca/en/aviation. It is also available at regulations.gov under Docket No. FAA-2026-1336. 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: Erica Bayles, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone: 907-271-5844; email: [email protected].