Airworthiness Directives; Eurocopter France Model AS 350 B, BA, B1, B2, B3, and D, and Model AS355 E, F, F1, F2, and N Helicopters

We are adopting a new airworthiness directive (AD) for the Eurocopter France Model AS 350 B, BA, B1, B2, B3, and D, and Model AS355 E, F, F1, F2, and N helicopters, with certain main rotor servo- controls and tail rotor servo-controls. This AD requires replacing all servo-controls that are identified in the Applicability section of this AD. This AD is prompted by an internal review conducted by the manufacturer which revealed that some main and tail rotor servo- controls do not conform to the approved design. The actions specified by this AD are intended to prevent the distributor slide valve jamming in its sleeve, leading to reduced controllability of the rotors and subsequent loss of control of the helicopter.