On July 13, 1999, at 0913 central daylight time, a Hughes OH-6A, N911EP, sustained substantial damage during an autorotational landing to the surface. The pilot and check pilot reported no injuries. The public use flight was operating under provisions of 14 CFR Part 91 in visual meteorological conditions. No flight plan was on file. The local flight departed at 0830. The flight was for the purpose of the pilot-in-command receiving a check ride from a check pilot (flight instructor). In a verbal statement given to a Federal Aviation Administration inspector, the check pilot said that the pilot had been practicing various landings including autorotational landings to a hover. He said that on the seventh landing he told the pilot to "demonstrate a full touchdown." He said the helicopter touched down hard and the main rotor blade contacted and cut through the tail boom. A post accident examination failed to reveal any pre-existent mechanical anomalies.