Final rule · 2026-21664

Airworthiness Directives; MD Helicopters, LLC Helicopters

The FAA is adopting a new airworthiness directive (AD) for certain MD Helicopters, LLC (MDHI) Model 369D, 369E, 369F, 369FF, 369H, and 500N helicopters. This AD was prompted by a report of mechanical damage to the main transmission drive shaft coupling (coupling). This AD requires 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 issuing this AD to address the unsafe condition on these products.