Summary
We propose to supersede airworthiness directive (AD) 2013-21- 01 that currently applies to Eurocopter France Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters. AD 2013-21-01 currently requires certain inspections of each tail rotor pitch horn assembly (pitch horn) for a crack and, if there is a crack, before further flight, replacing the pitch horn with an airworthy pitch horn. AD 2013-21-01 also requires a one-time visual inspection for pitch horns above certain hours time-in-service (TIS). This NPRM would retain the requirements of AD 2013-21-01 but would require a repetitive visual inspection for all pitch horns regardless of hours TIS, which requires allowing the public an opportunity to comment. These proposed actions are intended to detect a crack in the pitch horn to prevent failure of the pitch horn, loss of the anti-torque function, and subsequent loss of control of the helicopter.