On June 23, 2000, about 0730 Eastern Daylight Time, an Enstrom 280 FX, N383MA, operated by Northstar Helicopters on an aerial observation flight was substantially damaged during a forced landing in Springdale, Ohio. The certificated pilot and passenger were not injured. Visual meteorological conditions prevailed for the local flight that was conducted under 14 CFR Part 91. The helicopter was being used for aerial observation of traffic conditions. The pilot reported that he was cruising about 1,200 feet MSL (500 feet AGL), when the helicopter yawed nose right momentarily, followed by the engine running intermittently. He was over a divided freeway with residential areas on both sides of the freeway. The area between the roadways was sloped and unsuitable for landing, so the pilot elected to land on the side of the road, with the flow of traffic. When he lowered the collective, the engine quit. An autorotation to a run-on landing was conducted. After initial touchdown, the left skid transitioned from asphalt to soft dirt/grass. The skid dug in and the nose rotated left, after which, the helicopter came to rest on its right side. The occupants then exited the helicopter. The pilot further reported that he had checked the helicopter before departure and the check included both a visual examination of the fuel gage, and removing the fuel cap and looking into the fuel tank. The fuel tank was full before departure. According to the operator, on the day before the accident, the helicopter was used to give rides from a location near the Cincinnati Lunken Airport. According to the pilot who gave the rides, the company had positioned a portable refueling tank at the location and fuel was added periodically to the helicopter. The amounts added were not recorded, but the fuel tank was never filled to capacity. He reported that he flew about 4.7 hours. Before returning to the heliport, he added fuel, but did not remember the amount added. He said he was not certain how much fuel was in the helicopter, but thought the fuel tank was about 3/4 full upon departure. He also reported that he did not refuel the helicopter upon return to his home heliport. According to the inspector from the Federal Aviation Administration (FAA), the fuel cap was in place with no evidence of leakage. There was no smell of fuel at the accident site, and no evidence of a fuel spill. The helicopter was placed on a trailer and returned to the operator's facility. Examination of the fuel system revealed no breaks in the lines and all fuel line fittings were tight with no evidence of leakage. The fuel system was drained and about one quart of gasoline was recovered. The helicopter had flown 1.2 hours since takeoff. With the fuel tank drained, fuel was added in 5-gallon increments. With no fuel, and with 5 gallons added, the fuel gauge read zero pounds of fuel. All subsequent additions of fuel, the fuel gauge read less than was actually onboard. The engine was then started and ran with no problems noted. The FAA inspector further reported that he interviewed the pilot who reported: "That he [the pilot] did not check the fuel quantity visually prior to departing for the flight and that he did not pay too much attention to the fuel gage during the flight." The accident pilot reported his total flight experience as 5,114 hours, with 4,200 hours in Enstrom Helicopters. He had flown 175 hours in the preceding 90 days.