Airworthiness Directives; de Havilland Model DHC-8-100, -200, and -300 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to all de Havilland Model DHC-8-100, -200, and -300 series airplanes, that requires installation of a placard on the instrument panel of the cockpit to advise the flightcrew that positioning of the power levers below the flight idle stop during flight is prohibited. This amendment also requires eventual installation of a system that will prevent such positioning of the power levers during flight. Such installation will terminate the requirement for installation of a placard. This amendment is prompted by reports of operation of the airplane with the power levers positioned below the flight idle stop during flight. The actions specified by this AD are intended to prevent such positioning of the power levers below the flight idle stop during flight, which could cause engine overspeed, possible engine damage or failure, and consequent reduced controllability of the airplane.