Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters. This proposed AD was prompted by an occurrence reported where during an inspection of a tail rotor head (TRH) pitch change spider, excessive play and excessive wear were detected, due to an unwanted rotating motion. This proposed AD would require, for helicopters with certain part-numbered TRH spider pitch change units installed, inspecting for correct installation of the spider pitch change nut (nut); marking a 2 to 5 mm wide black paint index mark and repetitively inspecting the alignment of the marking; and additional inspections and corrective actions if necessary. This proposed AD would allow an affected part to be installed on a helicopter if certain requirements of this proposed AD are met. The FAA is proposing this AD to address the unsafe condition on these products.