On July 4, 2007, about 1015 mountain standard time, a Rajhamsa XAIR, N521F, veered off the runway during landing at the Flying J Ranch Airport, Pima, Arizona. The experimental airplane impacted a dry wash bed and sustained substantial damage with a bent fuselage. The airplane was owned and operated by the pilot. The student sport pilot was seriously injured. Visual meteorological conditions prevailed at the time of the solo instructional flight, and no flight plan had been filed. The flight was performed under the provisions of 14 CFR Part 91, and it originated from Wilcox, Arizona, about 0900. The pilot's son reported to the National Transportation Safety Board investigator that he was waiting for his father to arrive at the airport, and he witnessed his father's approach to runway 18. The son reported that the approach appeared normal. The son stated that he believed his father encountered a gust of wind during landing, and thereafter, he lost control of the airplane. The airport's owner reported that his privately owned, public-use, airport's runway was 45 feet wide and 2,950 feet long. The dirt surface was in good condition. The owner stated that the accident airplane appeared to have touched down on the center of the runway, about 500 feet upwind of the threshold. Thereafter, the airplane veered left, exited the left side of the runway, and went into a dry wash bed. At the time, a light breeze was blowing from the east about 15 miles per hour. As of August 4, 2007, the National Transportation Safety Board has not received the "Pilot/Operator Aircraft Accident Report," form number 6120.1/2. The pilot's flight hours listed in this report are estimates.