Airworthiness Directives; Eurocopter France Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1, AS355F2, and AS355N Helicopters

This amendment supersedes an existing airworthiness directive (AD) for the specified Eurocopter France (ECF) model helicopters that currently requires certain inspections of the main rotor swashplate bearing (bearing) and plugging the nonrotating swashplate vent holes and barrel nut orifices. This amendment eliminates most of those AD actions, which are now included in the Airworthiness Limitations section of the maintenance manual, but retains the requirements for the inspections and lubrication of the main rotor swashplate. This amendment also clarifies that repetitive maintenance of the main rotor swashplate and bearing is required at intervals not to exceed 100 hours time-in-service (TIS). This amendment is prompted by the need to clarify the AD wording to avoid any misinterpretation of the required interval for inspecting and lubricating the main rotor swashplate and bearing. The actions specified by this AD are intended to prevent failure of the bearing and subsequent loss of control of the helicopter.