Airworthiness Directives; Airbus Helicopters

We are publishing a new airworthiness directive (AD) for Airbus Helicopters Model AS332C, AS332C1, AS332L, and AS332L1 helicopters, which was sent previously to all known U.S. owners and operators of these helicopters. This AD requires inspecting certain tail rotor (T/R) blades, replacing the set of T/R blades if there is damage, deactivating the rotor de-icing system, revising the rotorcraft flight manual (RFM), and installing a placard. This AD is prompted by a report of a T/R de-icing system power supply box stuck in a ``closed'' position providing an uncontrolled and un-annunciated power supply to the system. These actions are intended to detect and prevent structural damage to the T/R blades caused by overheating, and subsequent loss of control of the helicopter.