Home / Agencies / DOT / 2026-13365
Proposed Rule

Airworthiness Directives; MD Helicopters, LLC Helicopters

Agency
DOT
Document Number
2026-13365
Published
July 1, 2026
Effective Date
-

Abstract

The FAA proposes to adopt a new airworthiness directive (AD) for certain MD Helicopters, LLC (MDHI) Model 369D, 369E, 369F, 369FF, 369H, and 500N helicopters. This proposed AD was prompted by a report of mechanical damage to the main transmission drive shaft coupling (coupling). This proposed AD would require a one-time visual inspection of the couplings for cracks of the splines and, depending on the results, replacement of the couplings. The FAA is proposing this AD to address the unsafe condition on these products.

Federal Register Source

This document is published by the Office of the Federal Register, National Archives and Records Administration. Access the full regulatory text, preamble, and docket comments below.

View Full Text on FederalRegister.gov →

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Frequently Asked Questions

What is the 2026-13365 Federal Register document?
Document 2026-13365 is a Proposed Rule published by the Department of Transportation in the Federal Register on July 1, 2026. The FAA proposes to adopt a new airworthiness directive (AD) for certain MD Helicopters, LLC (MDHI) Model 369D, 369E, 369F, 369FF, 369H, and 500N helicopters. This proposed AD was prompted by a report of mechanical damage to the main transmission drive shaft coupling (coupling). This proposed AD would require a one-time visual inspection of the couplings for cracks of the splines and, depending on the results, replacement of the couplings. The FAA is proposing this AD to address the unsafe condition on these products. View the original at https://www.federalregister.gov/documents/2026/07/01/2026-13365/airworthiness-directives-md-helicopters-llc-helicopters.
Is document 2026-13365 an economically significant rule?
No. Document 2026-13365 is not classified as economically significant under Executive Order 12866. Economically significant rules require OIRA review and are estimated to have impacts of $100 million or more per year.

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