Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Leonardo S.p.a. Model AB139 and AW139 helicopters. This proposed AD was prompted by a report of a damaged tail rotor duplex bearing (TRDB). This proposed AD would require repetitively inspecting certain TRDBs and depending on the results, replacing the TRDB or tail rotor actuator (TRA), or as an option, replacing the sliding control assembly. This proposed AD would also require replacing an affected TRDB with a serviceable TRDB at a specified threshold and prohibit the installation of certain TRDBs or sliding control assemblies on any helicopter, as specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference (IBR). The FAA is proposing this AD to address the unsafe condition on these products.