Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell), Model 205A-1, 205B, 210, and 212 Helicopters

This amendment supersedes an existing airworthiness directive (AD) for Bell Model 205B and 212 helicopters with certain main rotor blade (blade) assemblies installed. That AD currently requires washing the upper and lower surfaces of each blade and visually inspecting the grip plates, doublers, and the remaining upper and lower surfaces of the blades in the area between blade stations 24.5 to 40 for an edge void, corrosion, or a crack. This amendment retains the requirements of that AD for the affected part-numbered blades but increases the scope and frequency of the inspections and expands the applicability to include the Model 205A-1 and 210 helicopters, additional blade part numbers, and all helicopter serial numbers for the affected helicopter models. This amendment also requires applying a light coat of preservative oil (C-125) to all surfaces of the blade in addition to the inspection areas as required in the existing AD. This amendment is prompted by an additional report of a fatigue crack on a blade installed on a Model 212 helicopter. The actions specified by this AD are intended to detect an edge void, corrosion, or a crack on a blade, and to prevent loss of a blade and subsequent loss of control of the helicopter.