The pilot reported that during the landing approach to a ridgeline airstrip, he deployed full wing flaps and descended to the touchdown point. About 15 ft above ground level, the airplane encountered a sink that he failed to recognize and arrest. The pilot further remarked that the approach speed was also a little too slow for the unstable air which likely increased the rate of descent. The airplane touched down hard, short of the touchdown point, and nosed over, coming to rest inverted. The left wing and empennage were substantially damaged.

The pilot reported no mechanical anomalies with the airplane that would have precluded normal operation.