Airworthiness Directives; Cessna Model 650 Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to all Cessna Model 650 airplanes, that requires inspecting to determine the part number of the actuator control unit (ACU) and replacing the ACU with a new, improved ACU if necessary. This AD also requires revising the Limitations section of the airplane flight manual. The actions specified by this AD are intended to prevent uncommanded movement of the horizontal stabilizer, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.