Airworthiness Directives; Gulfstream Aerospace Corporation Model G-159 (G-I) Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to all Gulfstream Aerospace Corporation Model G-159 (G-I) airplanes, that requires revising the Airplane Flight Manual (AFM) to prohibit positioning the power levers below the flight idle stop. This amendment is prompted by incidents and accidents involving airplanes equipped with turboprop engines in which the ground propeller beta range was used improperly during flight. The actions specified by this AD are intended to prevent loss of airplane controllability or engine overspeed with consequent loss of engine power caused by the power levers being positioned below the flight idle stop while the airplane is in flight.