Airworthiness Directives; Agusta S.p.A. Helicopters

We are publishing a new airworthiness directive (AD) for Agusta S.p.A. (Agusta) Model A109A and A109AII helicopters, which was sent previously to all known U.S. owners and operators of these helicopters. This AD requires checking and inspecting each main rotor blade (blade) for a crack and replacing any cracked blade before further flight. This AD is prompted by abnormal vibrations leading to a precautionary landing and a post-flight inspection finding of a crack in a blade. These actions are intended to detect a crack in a blade and prevent failure of a blade and subsequent loss of control of the helicopter.