Airworthiness Directive Issued for Eurocopter SA-365 Series

The FAA has issued an airworthiness directive for all Eurocopter SA365N, SA365N1, SA366G1, AS365N2, AS365N3, EC155B and EC155B1. The AD was prompted by the discovery of a cracked main rotor mast nut. This condition, if not corrected, could lead to complete failure of the mast nut, resulting in failure of the rotor mast and loss of control of the helicopter.