Airworthiness Directives; Agusta S.p.A. Helicopters

We are adopting a new airworthiness directive (AD) for certain Agusta S.p.A. Model AB412 and AB412 EP helicopters. This AD requires inspecting the tail rotor (T/R) drive shaft flanged adapter (adapter) for a crack and removing the adapter from service if there is a crack. This AD is prompted by a report of a crack found in an adapter. These actions are intended to detect a crack in the adapter and prevent failure of the T/R drive shaft, which could result in reduced control of the helicopter.