AD FAA-2012-0773

We are adopting a new airworthiness directive (AD) for Eurocopter Deutschland GmbH (Eurocopter) Model MBB-BK 117 C-2 helicopters. This AD requires inspecting the long tail rotor drive shaft assembly for blind rivets, and if any blind rivets are installed, replacing that shaft assembly. This AD was prompted by the discovery that some helicopters have blind rivets installed in the place of solid rivets in the long tail rotor drive shaft. The actions of this AD are intended to detect blind rivets installed in the long tail rotor drive shaft, which could lead to failure of the tail rotor drive shaft and subsequent loss of control of the helicopter.