AD FAA-2013-0623

We are adopting a new airworthiness directive (AD) for all Bombardier, Inc. Model CL-600-2B19 (Regional Jet Series 100 & 440), CL- 600-2C10 (Regional Jet Series 700, 701, & 702), CL-600-2D15 (Regional Jet Series 705), and CL-600-2D24 (Regional Jet Series 900) airplanes. This AD requires revising the airplane flight manual (AFM) by incorporating an emergency procedure for uncommanded yaw motion. This AD was prompted by reports of airplanes experiencing uncommanded rudder movements while in flight. We are issuing this AD to advise the flightcrew of procedures to address a possible failure of the voltage regulator inside the yaw damper actuator that could lead to uncommanded yaw movement and consequent loss of the ability to control the airplane.