Summary
The FAA proposes to supersede Airworthiness Directive (AD) 2008-10-01 and AD 2010-05-51, which apply to certain Eurocopter France (now Airbus Helicopters) Model EC120B helicopters. AD 2008-10-01 requires replacing certain part-numbered and serial-numbered spherical thrust bearings. AD 2010-05-51 requires repetitively inspecting the main rotor (M/R) head rotor hub (rotor hub) and, depending on the results, taking corrective action. Since the FAA issued those ADs, the manufacturer revised the airworthiness limitations section (ALS) to incorporate various airworthiness limitations, tasks, and associated thresholds and intervals that were previously contained in service bulletins, as well as incorporate a new task. This proposed AD would require revising the ALS of the existing maintenance manual (MM) or instructions for continued airworthiness (ICAs) and the existing approved maintenance or inspection program, as applicable, as 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.