Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all de Havilland Model DHC-8-100, -200, and -300 series airplanes. This proposal would require 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 proposal also would require eventual installation of a system that would prevent such positioning of the power levers during flight. Such installation would terminate the requirement for installation of a placard. This proposal 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 the proposed 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.