Action
Final rule.
Summary
The FAA is adopting a new airworthiness directive (AD) for Leonardo S.p.a. (Leonardo) Model AB139 and AW139 helicopters. This AD requires removing certain main gearbox (MGB) input modules from service. This AD was prompted by the discovery that a batch of duplex bearings, which are installed on the MGB input modules, are defective. The actions of this AD are intended to address an unsafe condition on these products.