Summary
This document proposes the supersedure of an existing airworthiness directive (AD) applicable to BHTC Model 430 helicopters. That AD 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 a revision to the rotorcraft flight manual (RFM) to reflect the airspeed revision. This action would provide 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 proposal 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 the proposed AD are intended to prevent increased vibrations, damage to the main rotor system, and subsequent loss of control of the helicopter.