On May 21, 1997, at 1147 eastern daylight time, an Enstrom 280-C helicopter, N613LG, was destroyed when the main rotor blades collided with a building after lifting from a dolly at the Perl Acres Airport, Clarksburg, New Jersey. The certificated commercial pilot, the sole occupant, was seriously injured. Visual meteorological conditions prevailed and no flight plan had been filed for the local flight conducted under 14 CFR Part 91. In a telephone interview, the pilot reported that he backed the helicopter out of an aircraft hangar aboard an electrically powered dolly. He said the dolly batteries were not charged and that he used a battery charger and an extension cord to move the helicopter outside. The pilot explained that he intended to start the helicopter, warm it up, and check aircraft systems while the batteries charged on the dolly. Once the batteries were charged, he would move the helicopter a further distance from the hangar for takeoff. The pilot stated that he remembered sitting in the helicopter with the engine running and the rotors turning. He said he next remembered riding in an ambulance. He stated that he did not recall the accident. When asked to estimate the distance from the turning rotor blades to the hanger, the pilot said he had "...no idea." The pilot stated that he wanted to "...check out the dolly..." and that he was unclear if he intended to fly. He said that he remembered calling flight service. When questioned about the forecast winds he responded: "...8 to ten knots, I don't recall exactly." In a telephone interview, a Federal Aviation Administration Aviation Safety Inspector who responded to the scene stated that the helicopter came to rest in an upright position on the dolly. The helicopter dolly was powered by the extension cord because the batteries were not charged. He said that with the extension cord fully extended, the helicopter blades were only inches from the hanger with the rotors turning. The Inspector stated the helicopter was facing the hangar, oriented 155 degrees magnetic, with the tail into "...a very strong wind." He said an examination of the helicopter and the corrugated metal hanger revealed that the main rotor blades struck approximately 6 inches above the door opening and penetrated the building a distance of 2 feet, 7 inches. At Philadelphia, Pennsylvania, 25 miles west of Clarksburg, the winds were reported to be from 310 degrees at 14 knots, gusting to 22 knots.