Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Model 427 Helicopters

This amendment adopts a new airworthiness directive (AD) for the specified Bell model helicopters that requires replacing the hydraulic solenoid tee fitting (tee fitting) and tubes. This amendment is prompted by the manufacturer's discovery that tee fittings may be installed improperly and restrict hydraulic fluid flow. The actions specified by this AD are intended to prevent restricted flow of hydraulic fluid to the flight control hydraulic actuators resulting in loss of hydraulic control, excessive stiffness in the flight controls, and a subsequent forced landing of the helicopter.