Airworthiness Directives; Bell Helicopter Textron Canada (BHTC) Model 430 Helicopters

This amendment supersedes an existing airworthiness directive (AD) for BHTC Model 430 helicopters. That AD currently requires inspecting all four main rotor adapter assemblies for evidence of flapping and lead-lag contact. That AD also requires installing a never-exceed-velocity (VNE) placard with markings on the airspeed indicator glass and instrument case and revising the rotorcraft flight manual (RFM) to reflect the airspeed revision. This amendment provides mandatory terminating action for requirements of that AD by replacing the fluidlastic damper blade sets with improved sets that incorporate a pressure indicator to detect loss of damper fluid. This amendment is prompted by the need for a positive means of detecting loss of damper fluid that could result in main rotor tip path plane separation. The actions specified by this AD are intended to prevent increased vibrations, damage to the main rotor system, and subsequent loss of control of the helicopter.