Airworthiness Directives; Agusta S.p.A. (Agusta) Model AB412 Helicopters

This amendment adopts a new airworthiness directive (AD) that is applicable to Agusta Model AB412 helicopters with certain rescue hoists installed. This action requires replacing the rescue hoist hook assembly retention pin (retention pin) and periodically inspecting the rescue hoist. This amendment is prompted by an incident in which a rescue hoist hook assembly separated from a helicopter due to a missing retention pin. The actions specified in this AD are intended to prevent separation of the rescue hoist hook assembly from the helicopter due to failure of the retention pin. Loss of the rescue hoist hook assembly could result in loss of the person on the rescue hoist. Also, with the loss of the weight of the hoist cable assembly, the rescue hoist cable could become entangled with a main rotor or tail rotor blade, and result in damage or separation of a rotor blade and subsequent loss of control of the helicopter.