Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Leonardo S.p.a. Model A109C, A109E, A109K2, A109S, and AW109SP helicopters. This proposed AD was prompted by reports of loose tail rotor duplex bearing locking nuts, possibly caused by improper installation. This proposed AD would require disassembling certain tail rotor duplex bearings and reassembling them in accordance with updated service information. This proposed AD would also prohibit installing certain tail rotor duplex bearings. These actions are specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference. The FAA is proposing this AD to address the unsafe condition on these products.