On June 19, 1993, at about 1119 central daylight time, a Bell 47G, N3628G, registered to Dane H. Harris, Jr., operating as a 14 CFR Part 91 sightseeing flight, crashed on initial takeoff climb. The helicopter sustained substantial damage. The commercial pilot and two passengers sustained minor injuries. Visual meteorological conditions prevailed and no flight plan was filed. The flight originated from a private heliport about 1 minute before the accident. The pilot stated in an interview with the NTSB investigator-in-charge that he was conducting a takeoff with a quartering tailwind. At about 50 feet agl he encountered a downdraft and the rotor rpm began to deteriorate. He lowered the collective pitch to compensate for the loss of rotor rpm and observed a fence to his immediate front. Collective pitch was increased to clear the obstacle and a running landing was attempted to the sand. The helicopter's left skid collided with a pine tree and the helicopter rolled over on its right side. The investigation continues.