On April 8, 2002, about 0834 eastern daylight time, a Bell OH-58C, N107CS, registered to and operated by the Charlotte County Sheriff's Department, rolled over while attempting to lift off from a trailer at the Charlotte County Airport, Punta Gorda, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the public-use flight. The helicopter was substantially damaged and the commercial-rated pilot and one passenger (observer) were not injured. The flight was originating at the time of the accident. The pilot stated that the helicopter was positioned on a trailer that was located on the northeast sheriff's department ramp. After the engine start when he pulled "pitch", he felt the right skid pulling downward. He applied right cyclic input to counter the pulling and attempted to set the helicopter back down on the trailer. When he reduced pitch, the helicopter "...immediately let go from whatever was holding it down, and because of the applied right cyclic, the helicopter immediately began to roll to the right." He applied left cyclic which had no effect. The helicopter rolled off the trailer, contacted the ground, and came to rest upright. The main transmission and main rotor system separated from the helicopter. The pilot also stated that he had been trained at performing a couple or three liftoffs and landings from the trailer which was purchased from an individual in Wimauma, Florida, and was reportedly designed for an OH-58 helicopter. The accident sequence was videotaped on a surveillance camera, a copy of the tape was put on a CD and provided to the NTSB. Examination of the landing platform area of the trailer revealed the outer edges of both sides have an approximately 1.1875 inch high lip extending above the platform; the lip extends the length of the sides (see photograph 1). Additionally, four sections of round bar material are welded on top of the lip in four places on the sides of the trailer; two on each side near the ends. The pilot provided a digital photograph taken sometime before the accident date depicting the accident helicopter on the trailer. A review of that photograph revealed tie down straps used to secure the helicopter go over the round bar material (see photograph 2). Information provided by the pilot revealed that the landing platform area of the trailer is 95.250 inches wide; the skids measured 90.250 inches from outside edge to outside edge. Additionally, chipped paint was noted on a weld bead located on the left side of the platform near the forward portion where the round bar section was welded to the lip. Examination of the left skid revealed an indentation on the left forward outside portion of the skid (see photographs provided by the pilot with the NTSB Pilot/Operator Aircraft Accident Report).