Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

We are adopting a new airworthiness directive (AD) for Eurocopter Deutschland GmbH (ECD) Model EC135 P1, EC135 P2, EC135 P2+, EC135 T1, EC135 T2, and EC135 T2+ helicopters. This is the Federal Register publication of an Emergency AD (EAD) that was previously sent to all known owners and operators of these helicopters. That EAD superseded an earlier related EAD. This AD requires, before further flight and at specified intervals, checking and inspecting the upper and lower main rotor hub (MRH) shaft flanges for a crack, and inspecting the lower hub-shaft flange bolt attachment areas for a crack. This AD is prompted by three reported incidents of cracking on the lower hub-shaft flanges of EC135 model helicopters. These actions are intended to detect a crack on the hub-shaft flange, which if not corrected could result in failure of the MRH and subsequent loss of control of the helicopter.