On June 24, 2002, at 0900 eastern daylight time, a Bell 47G-2A helicopter, N8486E, registered to and operated by Airwork Enterprises of Florida, Inc., collided with power lines while maneuvering in a grove in La Belle, Florida. The aerial application flight was operated by the pilot under the provisions of Title 14 CFR Part 137 with no flight plan filed. Visual meteorological conditions prevailed at the time of the accident. The commercial pilot, the sole occupant, received minor injuries, and the helicopter sustained substantial damage. The flight originated in the grove in La Belle, Florida, about 0800. The pilot was executing swath runs to apply herbicide solutions to weed plants. While finishing with the second load of spray, the pilot maneuvered to turn the helicopter around and struck unmarked power lines approximately 75 to 100 feet above the ground. The pilot stated he was not aware the wires were there. The pilot then lost control of the helicopter, and it came down on its side and impacted trees. The pilot reported no mechanical malfunction with the helicopter. Examination of the wreckage revealed the main rotor system was damaged, the tail boom was separated, the canopy was shattered, and one skid was separated.