On November 21, 2004, about 1530 eastern standard time, an unregistered amateur built Sky Raider airplane, was substantially damaged when it impacted terrain, while maneuvering near a private airstrip in Rappahannock Academy, Virginia. The uncertificated pilot sustained serious injuries. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight conducted under 14 CFR Part 91. The pilot reported that he had not accumulated any flight time. He purchased the airplane about 2 years prior to the accident, and had practiced taxiing the airplane for about 20 hours. He intended to receive some flight instruction at a later date. On the day of the accident, the pilot was practicing taxiing the airplane, when it inadvertently became airborne. The pilot then elected to practice some approaches to the 1,400 foot-long, turf runway. He had been flying for about 10 to 15 minutes, and was in a right turn at an altitude of about 150 feet, when the airplane "stalled." The airplane pitched down and impacted the ground. Examination of the airplane by a Federal Aviation Administration inspector did not reveal any pre-impact malfunctions. Rotational damaged was noted on the propeller, and flight control continuity was verified to all primary control surfaces. Winds reported at an airport located about 11 miles northwest of the accident site, about the time of the accident were calm.