Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters

We are adopting a new airworthiness directive (AD) for certain serial-numbered Bell Helicopter Textron Canada Limited (BHTC) Model 206L, 206L-1, 206L-3, and 206L-4 helicopters with a certain tailboom upper left attachment fitting (fitting). This AD requires inspecting the fitting for a crack and other conditions. This AD was prompted by the manufacturer revising and extending the 100 hour time-in-service (TIS) inspection requirements for the fitting. The actions of this AD are intended to detect a crack, loose rivet, corrosion, or any other damage, which could lead to loss of the tailboom and subsequent loss of control of the helicopter.