The student helicopter pilot reported that he hovered to the parking pad and landed with the nose of the helicopter facing north. The skid placement on the parking pad was incorrect, and the instructor directed the student to reposition the helicopter about 3ft to the left. The student brought the helicopter to a hover and repositioned the helicopter 3ft to the left. However, before the student established a descent and landed, the helicopter encountered a tailwind gust. The nose pitched down, the rotor rpm decreased, and the helicopter traveled about 75ft forward. The skids contacted the ground hard, and the helicopter came to an abrupt stop, upright and facing downslope. The main rotor blades struck the tail rotor drive shaft and the tailboom. The tail rotor gear box and the tail rotor separated from the helicopter. The helicopter sustained substantial damage to the tail rotor drive system, the tailboom, and the main rotor blades. The airport's Meteorological Aerodrome Report, about the time of the accident, reported that the wind was from 180° at 15 knots, and the cloud layer was broken at 800ft. The predominant wind about 30 minutes prior to the accident was from 170° at 13 knots. One-hour prior, the wind was from 160 at 09 knots. The pilot reported that there were no mechanical malfunctions or failures with the helicopter that would have precluded normal operation.