On September 9, 2001, about 2000 Alaska daylight time, a wheel-equipped Rans S-7, an experimental, homebuilt airplane, N4012H, sustained substantial damage during takeoff from the Birchwood Airport, Chugiak, Alaska. The airplane was being operated as a visual flight rules (VFR) personal flight under Title 14, CFR Part 91, when the accident occurred. The solo student pilot sustained serious injuries. Visual meteorological conditions prevailed. During a telephone conversation with the National Transportation Safety Board investigator-in-charge on September 25, the pilot reported that the accident airplane had recently been rebuilt following a previous accident in 1996. The pilot stated that he intended to perform a few "high-speed taxi runs" on runway 19L, and that he was not intending to fly the airplane. He said that during the first taxi run, the nose of the airplane "felt heavy." He returned to the airplane's parking area, added about 60 pounds of ballast weight to the rear seat area, and taxied back to the threshold of runway 19L in preparation for a second taxi run. During the second taxi run, he said the airplane inadvertently became airborne, veered to the right, and climbed to about 150 feet above the runway surface. The pilot said that he applied full left rudder in an attempt to correct the turn, and at the same time reduced engine power in an attempt to land on runway 19R. The pilot said that all he could remember was that the airplane became inverted just before striking the ground. A witness reported that upon departure the accident airplane climbed very steeply to about 150 feet above the ground, with a very nose high attitude. He added that the airplane appeared to be "flying sideways when the left wing stalled, and the nose just dropped." He said the airplane descended almost straight down, before colliding with the ground in a very nose low attitude. He added that after impact, the airplane nosed over. The airplane sustained substantial damage to the wings, fuselage, and empennage. A Federal Aviation Administration (FAA) airworthiness inspector from the Anchorage Flight Standards District Office, traveled to the accident scene on September 10, and examined the airplane. The inspector reported that there were no preaccident mechanical anomalies noted with the airplane. He confirmed that control continuity was established. The accident pilot from the 1996 accident involving the same airplane (ANC96LA147) reported to the National Transportation Safety Board investigator-in-charge that the airplane was difficult to control at low speeds, and touchy on the controls. The pilot did not submit a Pilot/Operator report (NTSB form 6120.1/20).