Airworthiness Directives; Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to all Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes, that requires a one-time inspection for correct installation of the left- and right-hand fuel differential pressure (FDP) switches and for correct connection of the pressure sensing lines to the switches, and corrective action, if necessary. The actions specified by this AD are intended to ensure that a warning light goes on when the fuel filter is partially blocked by ice, so that the blockage of the fuel filter does not increase, leading to reduced fuel flow to the engine and possibly to an engine flame-out. This action is intended to address the identified unsafe condition.