On August 23, 2009, about 1737 Pacific daylight time, an Antares U.S. MA-34R 912 Ranger weight shift control airplane, N2356W, struck two parked airplanes following startup at the Reid Hillview Airport (RHV), San Jose, California. The owner/pilot operated the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The sport pilot instructor, the sole occupant of the airplane, was seriously injured; the airplane sustained substantial damage to the wings and fuselage. Visual meteorological conditions prevailed, and no flight plan had been filed for the cross-country personal flight. The intended destination was South County Airport of Santa Clara County (E16), San Martin, California. The student pilot reported that he had just completed an hour-long lesson in the airplane with the sport pilot instructor, who was going to return to his home airport. The student was standing about 10 feet behind the airplane when the instructor strapped into the front seat, put his helmet on, and yelled “clear.” The student was not able to see the position of the engine controls. Upon engine start, it immediately went to what the student thought was full or close to full power. The airplane lurched forward and to the right; the right wingtip clipped a sign, and the wing cables snagged on a parked Zlin airplane (N800NA). It hit with enough force to pull the Zlin out of its tiedown, and turn it 90 degrees. The accident airplane then swerved to the left and lifted up onto its rear wheels; its underside then struck the tail of a parked Citabria airplane (N1806G). The student estimated that the total time from engine start to coming to rest was just a few seconds. The instructor was unconscious and hanging upside down. The student and others removed the pilot from the airplane; the pilot regained consciousness within about a minute, but sustained serious injuries. A Federal Aviation Administration inspector examined the airplane. He determined that the dual control foot-operated throttle cables were intact and functioning normally. Both carburetors had become dislodged. The inspector cycled the carburetor control and observed that the right carburetor would hang up in the wide open position, but return to idle with minimal pressure. He noted some resistance in the left carburetor throttle control near the wide open position. He could not determine if these anomalies existed prior to the accident, or if impact damage affected these findings. He was able to establish control continuity.