Airworthiness Directives; Bell Helicopter Textron Canada Model 206A, A-1, B, B-1, L, L-1, L-3, L-4 Helicopters

This amendment adopts a new airworthiness directive (AD) for the specified Bell Helicopter Textron Canada (BHTC) model helicopters that requires, before the first flight of each day, checking the tail rotor blade (blade) root doublers (doublers) for an edge void or de- bond on both sides of each blade, and if an edge void or de-bond is found, replacing the unairworthy blade with an airworthy blade. This AD also requires replacing any affected serial-numbered blade with an airworthy blade. This amendment is prompted by reports of de-bond of the doublers due to inadequate surface preparation resulting in poor adherence of the doublers. The actions specified by this AD are intended to prevent loss of a blade, loss of tail rotor control, and subsequent loss of control of the helicopter.