On April 3, 1997, approximately 1830 central standard time, a Bell 47 helicopter, N90485, was substantially damaged following a loss of control while attempting to land on a stationary transport trailer, at Laredo International Airport, Laredo, Texas. The commercial rated pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed for the Title 14 CFR Part 91 personal flight. During an interview with the investigator-in-charge, the pilot stated that he was in the process of purchasing the helicopter from a business located at the airport. After a successful acceptance flight earlier that morning, the pilot landed the helicopter on the ramp, shut down, and finalized the deal. He had driven a trailer to the airport to transport the helicopter back to Louisiana after the purchase. The person that sold the helicopter to the pilot stated that he and the pilot discussed loading the helicopter onto the trailer utilizing a crane, but the pilot optioned to hover and land the aircraft on the trailer. Several witnesses observed the helicopter hovering over the trailer and attempting to land. They reported that as the helicopter touched down on the trailer, the right skid "slid off" the right side of the trailer. They subsequently observed the helicopter roll to the left and impact the ground, with the rotor blades striking the ground first. The pilot stated that he descended slowly down to the trailer platform, positioning the left skid as close to the left rail as possible. He further stated that upon touch down, the helicopter slid about 1 inch to the right, but the left skid looked square to the left rail. As he lowered the collective, he felt the helicopter drifting to the right skid and applied power and left lateral cyclic to arrest the drift. Subsequently, the craft banked sharply to the left and the rotor blades struck the ground. As the helicopter rolled to the left, the tail boom was severed. According to the pilot, this was the first time that he had landed on a trailer. A FAA inspector reported that the width of the trailer was about 4 inches wider than the helicopter's landing skids.