Airworthiness Directives; Dassault Model Mystere-Falcon 50 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Dassault Model Mystere-Falcon 50 series airplanes. This action requires a detailed inspection for clearance and chafing of the entire length of the hydraulic lines located within the engine pylons, and follow-on/corrective actions, as applicable. This action also requires a revision of the maintenance manual to ensure that the clamps that hold the hydraulic lines are in their initial position during normal maintenance, and that the position is identified with a yellow paint line. This action is necessary to prevent chafing and consequent leakage of the hydraulic lines located within the No. 1 and No. 3 engine pylons, which can result in failure of the No. 1 and No. 2 hydraulic systems, and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.