Airworthiness Directives; Dassault Model Mystere-Falcon 50 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Dassault Model Mystere-Falcon 50 series airplanes, that requires applying PR (fuel tank sealant) and installing PR patches over the internal side panel recesses of the left-hand and right-hand feeder tanks at certain frames and stringers. This action is necessary to prevent possible fuel ignition in the event of a lightning strike and consequent uncontained rupture of the fuel tank(s). This action is intended to address the identified unsafe condition.