Airworthiness Directives; Short Brothers Model SD3 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Short Brothers Model SD3 series airplanes, that requires repetitive tests (checks) of the engine power lever to ensure that the fuel control unit (FCU) lever is contacting the maximum stop, adjustment of the FCU rigging, if necessary, and an engine ground run for correct gas generator rotational speed. This AD also requires a static reduced power check on each engine to ensure correct operation of the reserve takeoff power (RTOP) system; and follow-on actions, if necessary. This action is necessary to prevent failure of the engines to reach adequate RTOP boost during takeoff, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.