FAA · Airworthiness Directive
Airworthiness Directives; MD Helicopters, LLC Helicopters
Abstract
The FAA proposes to supersede Airworthiness Directive (AD) 2024-23-06, which applies to certain MD Helicopters, LLC (MDHI) Model 369, 369A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters. AD 2024-23-06 requires repetitively inspecting the torque tube assembly and roller bearings, and depending on the results, replacing parts or accomplishing additional inspections. Since the FAA issued AD 2024-23-06, it has been determined that additional torque tube assemblies are affected by this unsafe condition. This proposed AD would continue to require the actions of AD 2024-23-06 and would expand the applicability. The FAA is proposing this AD to address the unsafe condition on these products.
Applicability
Aircraft makes and models this AD applies to, sorted by US-registered fleet size.
Federal Register text
Verbatim from the Federal Register publication — required actions, compliance times, parts/serial numbers, and methods of compliance. The Federal Register is the legally binding document; this rendering is for readability. Cite: 90 FR 51596.
[Federal Register Volume 90, Number 220 (Tuesday, November 18, 2025)] [Proposed Rules] [Pages 51596-51600] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 2025-20093]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-3987; Project Identifier AD-2025-00017-R] RIN 2120-AA64
Airworthiness Directives; MD Helicopters, LLC Helicopters
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) 2024-23-06, which applies to certain MD Helicopters, LLC (MDHI) Model 369, 369A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters. AD 2024-23-06 requires repetitively inspecting the torque tube assembly and roller bearings, and depending on the results, replacing parts or accomplishing additional inspections. Since the FAA issued AD 2024-23-06, it has been determined that additional torque tube assemblies are affected by this unsafe condition. This proposed AD would continue to require the actions of AD 2024-23-06 and would expand 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 January 2, 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-2025-3987; 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, any comments received, and other information. The street address for Docket Operations is listed above.
FOR FURTHER INFORMATION CONTACT: Eduardo Orozco-Duran, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (562) 627-5264; email: [email protected].