Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for Agusta S.p.A. Model AB139 and Model AW139 helicopters. This AD requires inspecting the thickness of the tail gearbox (TGB) central housing (housing). This AD was prompted by reports that the housing thickness does not conform to its type design. The actions of this AD are intended to detect and correct an unsafe condition on these products.