On July 11, 2003, at 1845 central daylight time, an amateur-built Spiker Rotorway 162F helicopter, N444T, sustained minor damage when it rolled over on its left side during an engine run-up at Creve Coeur Airport, St. Louis, Missouri. The pilot was not injured. Visual meteorological conditions prevailed during the engine run-up. The student pilot reported he was performing an engine run-up to check the engine and drive train. The pilot stated, "After run-up with collective throttle at about 100% the aircraft became airborne." The pilot reported he "immediately" lowered the collective to the full down position, but the helicopter was already beginning a roll to the left. The helicopter rotated onto its left side and came to a stop. The pilot remarked, "It is this pilot's opinion that the aircraft experienced a dynamic roll over condition." The pilot reported he did not intend to become airborne. The pilot reported no mechanical malfunctions or defects prior to the accident.