After flying to the resort, the pilot landed the helicopter and picked up a photographer for local area photography. He reported that the initial runs were flown at 500 feet above ground level. During some of these runs the wind changed in direction from north to east and was about 10 knots in speed. The pilot noticed on some occasions, when the wind was a tailwind, it caused control difficulties. On one pass, at about 200 feet above the ground and travelling forward at about 30 knots, the helicopter was again affected by a tailwind. The pilot was unable to prevent it yawing to the right. The rotor rpm decayed, collective was lowered, and the aircraft was flared at about 100 feet but the sink rate could not be arrested. The helicopter struck the ground at a high rate of descent but remained upright. Evaluation of the flight indicates that the pilot was flying very slowly with a tailwind. He lost directional control and insufficient power was available to sustain rotor rpm. The pilot later flared the aircraft too high too enable a landing at a safe rate of descent.