On January 27, 2002, about 1330 mountain standard time, a Richard S. Anderson, Rotorway Exec 162F, N30545, encountered a gust of wind while hovering in ground effect. The pilot lost control of his helicopter; it contacted the ground and rolled over. The accident occurred at a private residence about 12 miles north of Willcox, Arizona. The experimental helicopter was substantially damaged, and the student helicopter pilot received a minor injury. The solo instructional flight was performed under 14 CFR Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. The flight was initiated about 1325. The pilot reported to the National Transportation Safety Board investigator during a February 6, 2002, interview, that he held a private pilot certificate with a single engine land rating. At the time of the accident, he was in training to obtain a rotorcraft rating and was practicing for his certification check ride. The pilot had about 175 hours of experience flying airplanes, and 70 hours of rotorcraft flying experience. On January 4, 2002, the pilot's flight instructor had authorized him to practice solo flying in the accident helicopter in wind conditions not exceeding 10 mph. The pilot further reported that, during the accident flight, he had been hovering in ground effect in the prevailing 10 mph wind when an estimated 20 mph wind gust was suddenly encountered from his right side. The pilot stated that when he attempted to move the cycle control to the right to stabilize the helicopter, his right hand contacted his right thigh, which was against the installed right side collective control. This momentarily restricted his available range of cycle movement. The helicopter then drifted left, impacted the ground, and rolled over.