Federal Register #2026-13365

FAA Proposed Airworthiness Directive for MD Helicopters – Driveshaft Coupling Inspection and Replacement

The Federal Aviation Administration (FAA) is proposing a new airworthiness directive (AD) for MD Helicopters, LLC models 369D, 369E, 369F, 369FF, 369H, and 500N. - Government Buyer: - Federal Aviation Administration (FAA), Department of Transportation - OEM Highlight: - MD Helicopters, LLC is the only OEM specifically referenced - Products/Services Requested: - Main transmission drive shaft coupling (part number 369H5660) - Applies to serial numbers 85640001 through 85640308 - Approximately 568 U.S. helicopters affected - One-time visual inspection for cracks using bright light and 10X magnification - Replacement of coupling if cracks are found, or within 300 flight hours even if no cracks are found - Notable Requirements: - Compliance is mandatory for safety and regulatory reasons - The directive references specific MD Helicopters service bulletins (SB369H264R1, SB369D230R1, SB369E130R1, SB369F121R1, SB500N067R1) - The action is a regulatory compliance requirement, not a direct procurement of goods or services - FAA also proposes regulatory changes to streamline maintenance inspection privileges for certificated mechanics

Description

The FAA proposes a new airworthiness directive for certain MD Helicopters, LLC models 369D, 369E, 369F, 369FF, 369H, and 500N. This directive is prompted by reports of mechanical damage to the main transmission drive shaft coupling. It requires a one-time visual inspection of the couplings for cracks and, depending on findings, replacement of the couplings to address unsafe conditions and prevent potential failure leading to loss of power to the main rotor blades.

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