The helicopter pilot stated that the purpose of the approximate 2-hour cross-country flight was to perform aerial mapping of powerlines. The helicopter was due for a fuel pump replacement at the end of the flight and maintenance personnel requested that the pilot land with as little fuel as possible. He departed with 60 gallons of fuel and thought he would land with about 10 gallons; however, the flight took longer than the pilot anticipated. About 2 hours, 15 minutes into the flight, as the helicopter was in a 50-foot hover over the destination airport, the engine lost all power. The pilot performed an autorotation to a taxiway, but the helicopter landed hard and the tailboom separated. The pilot added that the accident would not have happened if he followed the Federal Aviation Regulation minimum fuel requirements and had properly calculated time and fuel consumption. The pilot also reported that there were no preimpact mechanical malfunctions with the helicopter and examination of the wreckage by a Federal Aviation Administration inspector did not reveal any.