On January 29, 2001, at 1630 mountain standard time, a S.N.I.A.S. SE 3130 Alouette II, N31330, registered to and operated by J.H. Jet as a 14 CFR Part 91 pleasure flight, rolled over on the ramp at Reed Memorial airport, Driggs, Idaho. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local flight. The helicopter was substantially damaged and the airline transport pilot and his two passengers were not injured. The flight originated from Driggs about one hour and 30 minutes prior to the accident. During a telephone interview and subsequent written statement, the pilot reported that the local sightseeing flight was uneventful. When they returned to the airport, the pilot entered into a hover over the departure end of runway 21 to hover taxi to the ramp. The pilot stated that the helicopter touched down on the ramp and he lowered the collective to unload the main rotor blades. At this point the cyclic control started shaking "very violently" in his hand along with the helicopter starting to move forward and aft. The pilot thought that it might be ground resonance and lifted the helicopter back off to about a three to six foot hover. The conditions worsened as the helicopter began to oscillate and could not be stabilized. The pilot raised the hover to about 10 to 12 feet, and lowered the collective thinking that it might reduce the movement. When that did not help, the pilot turned the helicopter about 90 degrees to verify the location of a fuel truck. When the truck was located, the pilot then turned the helicopter back to the right and prepared to touchdown, cautioning his passengers that the helicopter might roll after touchdown. During the landing, the right rear skid contacted the ground first and the helicopter tipped forward to the right and started to roll. The helicopter rolled over to the right and came to rest on its right side. After the accident, the main rotor dampers were removed from the helicopter. The mechanic from Teton Aviation Center, Driggs, Idaho, performing the inspection reported that, "Functional checks of the dampers showed normal operation. Disassembled dampers and inspected, found no obvious damage or hidden damage that would cause abnormal function."