During an aerial application flight, the pilot was making a spray pass at approximately three feet above the crop. During the pass the engine sputtered and died. He entered an autorotation and attempted to slow from 50 mph. The aircraft impacted terrain and came to rest on its side. The pilot noted the helicopter was refueled about an hour prior to the accident. An FAA inspector reported the helicopter was not refueled to its proper quantity, causing the pilot to miscalculate the fuel aboard. Post-impact inspection revealed an estimated two gallons or less of fuel in the intact tank.
