On July 5, 2004, at 1500 Pacific daylight time, a Robinson R-22 Mariner, N856HA, registered to and operated by Hillsboro Aviation as a 14 CFR Part 91 instructional flight, experienced a hard landing followed by a rollover at the Portland-Hillsboro Airport, Hillsboro, Oregon. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local instructional flight. The helicopter was substantially damaged and the certified flight instructor was not injured, while the commercial pilot (student) received minor injuries. In a written statement, the flight instructor reported that they were in the process of practicing "maximum performance takeoff abort - backwards." The student was on the controls during the maximum performance takeoff phase to an altitude of about 150 feet above ground level, and the instructor took over the controls to demonstrate the abort procedures. The instructor took the controls just prior to call for the abort. When the abort phase began, the instructor applied aft cyclic and slightly lowered the collective. The helicopter had been in a tail low attitude and started to descend into "settling with power." The instructor applied forward cyclic and lowered the collective, however the helicopter did not have sufficient altitude to level out or gain airspeed to recover before impacting the ground on the right side skid. The helicopter pivoted around about 180 degrees then rolled over onto its left side.