Summary
The FAA proposes to supersede Airworthiness Directive (AD) 2021-04-21, which applies to certain Airbus Helicopters Model EC120B helicopters. AD 2021-04-21 requires an inspection of the attachment bolts of the main rotor (MR) hub scissors assembly for discrepancies and repair if necessary; part marking of the attachment bolts of the MR hub scissors assembly; and repetitive inspections of the part marking of the attachment bolts, and repair if necessary. Since the FAA issued AD 2021-04-21, the FAA has determined that additional part marking of the washer, scissor branch, and mast ring of the corresponding nut side, and repetitive inspections of the additional part markings are necessary. This proposed AD would continue to require the actions in AD 2021-04-21; and also would require part marking of the washer, scissor branch, and mast ring of the corresponding nut side, and repetitive inspections of the additional part markings and repair if necessary; as specified in a EuropeanUnion 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.