Airworthiness Directives; Eurocopter France Model SA-365C, C1, C2, N, and N1; AS-365N2; and SA-366G1 Helicopters

This amendment adopts a new airworthiness directive (AD), applicable to Eurocopter France Model SA-365C, C1, C2, N, and N1; AS- 365N2; and SA-366G1 helicopters, that requires inspecting the tightening torque of the main rotor hub blade attach beam spherical thrust bearing bolts (bolts). This AD also requires either applying the specified torque or, if necessary, conducting a dye penetrant inspection for cracks in the metal components. Replacing the spherical thrust bearing (bearing) with an airworthy bearing is also required if a crack is found. This amendment is prompted by reports of cracks in the metal components of the bearing attachment joint. The actions specified by this AD are intended to prevent loosening of bearing bolts in flight, which may cause cracks in the metal components, failure of the bearing, and subsequent loss of control of the helicopter.