On November 8, 2001, about 1145 central standard time, a Smith Aerostar 601, N128AC, piloted by a commercial pilot, sustained substantial damage during landing on runway 34 (3,999 feet by 100 feet, asphalt) at the Vermillion County Airport, Danville, Illinois. The 14 CFR Part 91 positioning flight was on an instrument flight rules flight plan and was operating in visual meteorological conditions. The pilot, who was the sole occupant, was not injured. The flight originated from the General Mitchell International Airport, Milwaukee, Wisconsin, about 1045. The pilot reported that during the landing, he heard a loud noise and the airplane veered off of the runway. Upon inspection, the landing gear scissor assembly was found broken loose from the upper mounting collar on the landing gear strut and the lower strut was rotated about 90 degrees. A request was made that the broken parts be sent to the National Transportation Safety Board investigator for further examination. As of March 8, 2002, the parts had not been received. No other anomalies were found with the airplane or its systems that could be associated with a pre-impact condition.