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AD 2025-11449

Published 2025-06-23 · 4 models · 801 US-registered tails affected · Federal Register

Airworthiness Directives; Bell Textron Canada Limited Helicopters Federal Register ↗

Abstract

The FAA is adopting a new airworthiness directive (AD) for all Bell Textron Canada Limited (BTCL) Model 407 and 427 helicopters. This AD was prompted by a report that certain expandable blade bolts installed on the main rotor blade may not have received the correct heat treatment, which could result in stress corrosion cracking of the expandable blade bolts. This AD requires removing the expandable blade bolts from service and replacing them with a part eligible for installation. This AD also prohibits the installation of an affected expandable blade bolt on any helicopter. The FAA is issuing this AD to address the unsafe condition on these products.

Applicability · by US fleet size

Federal Register text

Verbatim; the Federal Register publication is the legally binding document. Cite: 90 FR 26424. View on Federal Register ↗

[Federal Register Volume 90, Number 118 (Monday, June 23, 2025)] [Rules and Regulations] [Pages 26424-26427] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 2025-11449]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-1111; Project Identifier MCAI-2025-00675-R; Amendment 39-23067; AD 2025-13-01] RIN 2120-AA64

Airworthiness Directives; Bell Textron Canada Limited Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all Bell Textron Canada Limited (BTCL) Model 407 and 427 helicopters. This AD was prompted by a report that certain expandable blade bolts installed on the main rotor blade may not have received the correct heat treatment, which could

[[Page 26425]]

result in stress corrosion cracking of the expandable blade bolts. This AD requires removing the expandable blade bolts from service and replacing them with a part eligible for installation. This AD also prohibits the installation of an affected expandable blade bolt on any helicopter. The FAA is issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective July 8, 2025. The FAA must receive comments on this AD by August 7, 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 p.m., Monday through Friday, except Federal holidays. AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2025-1111; 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 street address for Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Adam Hein, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 946-4116; email: [email protected].