Two pilots were attempting to reposition the vintage, experimental-exhibition category helicopter into a hangar to protect it from hail damage before a severe cold front arrived. The pilots initially attempted to land the helicopter on a movable skid, but because the skid was too close to a building (given the wind conditions), the pilots landed the helicopter before one of the pilots disembarked and moved the skid. The accident pilot then took off in the helicopter and flew in a roughly circular pattern to approach the skid for landing. During the flight the helicopter “developed a severe shake,” so the pilot decided to immediately land the helicopter on the grass below. During the landing, the helicopter’s tail rotor struck the ground, substantially damaging it and its mount/drive system. The pilot reported that there were no preimpact mechanical malfunctions or failures of the helicopter that would have precluded normal operation. He further described that at the time of the accident the wind velocity was about 30 knots, and “I wish it had not been so windy, with the wind whipping around the building. If the skid had been in an area of clear air, it would have been fine.”