Airworthiness Directives; Leonardo S.p.a. Helicopters

The FAA is adopting a new airworthiness directive (AD) for all Leonardo S.p.a. Model A109C, A109E, A109K2, A109S, and AW109SP helicopters. This AD was prompted by reports of loose tail rotor duplex bearing locking nuts, possibly caused by improper installation. This AD requires disassembling certain tail rotor duplex bearings and reassembling them in accordance with updated procedures. This AD also prohibits installing certain tail rotor duplex bearing housings and pitch change slider assemblies. These actions are 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.