AD Proposed for MD 369/500 Cargo Hook Overrunning Clutch

The FAA has proposed a new airworthiness directive (AD) that would supersede AD 90-19-02 for all MD Helicopters Model 369, 369A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, and 500N helicopters equipped with a cargo hook. The proposal was prompted by a Model 369E forced landing after a total loss of engine power. Investigators traced the loss of power to inadequate regreasing of the overrunning clutch output bearing, which caused heat damage and failure of the clutch inner race. They also found a gap in the original AD’s applicability that allowed some aircraft operate without the required inspections. The FAA has also determined that the Model 500N is subject to the same unsafe condition.

For helicopters with overrunning clutch assembly P/N 369A5350-BSC, -601, or -603 installed, the proposed AD would require that, within 300 hours time-in-service (TIS) or at the next annual inspection (whichever comes first), operators replace any clutch subassembly other than P/N 369A5350-41 or -51 and reidentifying the assembly as P/N 369A5350-605. All affected helicopters would also need their airworthiness limitations revised within 30 days. The revision would add a 1,800-hour life limit on the sprag assembly and require inspections of the sprag and the clutch inner and outer races every 300 hours TIS or 12 months. The FAA estimates 568 U.S.-registered helicopters are affected but believes most already have the -605 assembly installed. Comments are due December 18, 2026. You can view the proposed AD here.