Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron Canada (BHTC) Model 407 helicopters that requires replacing certain cockpit warning horns. This amendment is prompted by reports that pilots have had difficulty in distinguishing between the FADEC Fail horn, the Engine Out horn, and the Low Rotor RPM horn. The actions specified by this AD are intended to assist the pilot in properly identifying a specific cockpit warning horn (horn) and prevent an inappropriate pilot response to a horn, which could cause an engine overspeed and subsequent uncommanded reduction to flight-idle engine power.