AD FAA-2012-0355

We are adopting a new airworthiness directive (AD) for Agusta S.p.A. (Agusta) Model AB412 helicopters with certain tail rotor blades (blades) installed. This AD requires, before further flight, removing and replacing each affected blade with an airworthy blade. This AD is prompted by incidents where a blade tip weight separated from a blade in flight on other model helicopters with common part-numbered blades. It has been determined that this unsafe condition may also exist on the specified Agusta model helicopters. The actions specified in this AD are intended to prevent loss of the blade tip weight, loss of a blade, and subsequent loss of control of the helicopter.