Airworthiness Directives; Leonardo S.p.a. (Type Certificate Previously Held by Agusta S.p.A.) Helicopters

The FAA is superseding Airworthiness Directive (AD) 2017-23-08 for Agusta S.p.A. (now Leonardo S.p.a.) Model AB139 and AW139 helicopters. AD 2017-23-08 required repetitively inspecting the main rotor (M/R) rotating scissors, removing certain lower half scissor spherical bearings (bearings) from service, replacing the removed bearings with a new bearing, and installing a special nut. This new AD retains the requirements of AD 2017-23-08 and requires replacing each affected bearing with a certain part-numbered bearing. This AD was prompted by investigation results determining that a quality control issue may have affected the production of the affected bearings. The actions of this AD are intended to address an unsafe condition on these products.