Summary
This document proposes adopting a new airworthiness directive (AD) for Eurocopter France (ECF) Model AS350B, AS350B1, AS350B2, AS350B3, AS350BA, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters. This proposal would require replacing the tail rotor hub pitch change plate "SNR" bearing (bearing). This proposal is prompted by fatigue cracks found in the bearings. The actions specified by the proposed AD are intended to prevent seizure of the bearing, loss of tail rotor effectiveness, and subsequent loss of control of the helicopter.