On May 12, 1994, about 1230 central daylight time, a Bell 206B helicopter, N49585, sustained substantial damage when it struck a power line and crashed near Winnebago, Illinois. Neither the airline transport certificated pilot nor the single passenger aboard the helicopter were injured. The business flight originated at Rockford, Illinois, about 1215, with an intended destination of Galena, Illinois. No flight plan was filed, and visual meteorological conditions prevailed at the time. The pilot-rated passenger who was seated in the right seat was flying the helicopter when it departed Rockford. He stated the purpose of the flight was to follow some cars to Galena. He said he was flying at 1200 feet following highway 20 westbound. After the helicopter cleared the Rockford Regional Airport's airspace, the passenger stated the pilot took control of the helicopter and descended to about 30 feet above the road while following the cars. He said the helicopter was below the tree line. He stated the pilot pulled the helicopter up sharply when wires were seen in their flight path. The helicopter struck one of the wires. The pilot made an autorotation to a field north of the highway. The helicopter rolled over after landing.