Airworthiness Directives; Eurocopter France Model AS350B, B1, B2, B3, BA, D, D1 and AS355E, F, F1, F2, and N Helicopters

This amendment supersedes an existing airworthiness directive (AD) that applies to Eurocopter France (ECF) Model AS350B, B1, B2, B3, BA, D, AS355E, F, F1, F2, and N helicopters. That AD requires inspecting certain versions of the tail rotor pitch change spider assembly (spider assembly) for the proper rotational torque, axial play, and any brinelling of the bearing. This AD requires identifying the spider assembly with index marks to detect bearing spacer rotation, visually checking to ensure that the index marks are aligned before the first flight of each day, and subsequently modifying the spider assembly. This AD also adds the ECF Model AS350D1 helicopters to the applicability. This AD is prompted by operator reports that the spider assembly bearing spacers are rotating. The actions specified by this AD are intended to detect rotation of the spider assembly bearing spacers, prevent seizure of the bearing, loss of tail rotor control, and subsequent loss of control of the helicopter.