AD FAA-2012-0409

We are publishing a new airworthiness directive (AD) for certain Agusta S.p.A. (Agusta) Model AB139 and AW139 helicopters that requires establishing a revised life limit for each tail rotor (T/R) blade and updating the helicopter's historical records, repetitively inspecting T/R blades for a crack, and replacing certain T/R blades. This AD is prompted by a fatal accident involving an Agusta Model AW139 helicopter, which may have been caused by cracks in a T/R blade. These actions are intended to detect and prevent a crack in a T/R blade, which could lead to failure of a T/R blade and subsequent loss of control of the helicopter.