Airworthiness Directives; Airbus Helicopters Deutschland GmbH

The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, and EC635T2+ helicopters. This AD was prompted by reports of improper heat treatment of titanium (Ti)-bolts installed on the forward and aft tail rotor drive shafts, resulting in a broken Ti-bolt. This AD requires an inspection to determine if Ti-bolts installed on the forward and aft tail rotor drive shafts are affected parts, and replacement if necessary, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.