At approximately 1755 Central time, the airplane sustained minor damage during an in-flight separation of the elevator trim cable following runaway activation of the electric trim system. The airplane was in visual conditions at approximately 6000 feet msl on an autopilot descent from an en route cruise at 19,000 feet. The solo pilot was not injured. While in an 800-fpm descent at about 180 to 190 knots, the pilot noticed the elevator pitch trim was rotating continuously in the nose-up position. After disconnecting the autopilot, the pitch trim stopped moving and the pilot could manually turn the pitch trim wheel without force or resistance. He hand-flew the airplane to an uneventful landing using spoilers, 15 degrees of flaps and approximately 10 to 20 pounds of back pressure on the yoke to keep the airplane in level flight. Examination revealed the pitch trim cable was completely separated in the area where it passes over the rearmost pulley in the tail cone.
