On July 17, 1998, about 1000 eastern daylight time, an experimental kit-built Velocity RG, N96HV, registered to a private individual, operating as a 14 CFR Part 91 personal flight, crashed short of Sebastian Municipal Airport, Sebastian, Florida. Visual meteorological conditions prevailed and no flight plan was filed. The airplane received substantial damage and the private-rated pilot sustained serious injuries. The flight originated about one hour before the accident from Valkaria Airport, Valkaria, Florida. According to the pilot's statement, when he tried to reduce power for descent and landing at Valkaria, he experienced a stuck or disconnected throttle. He decided to land at nearby Sebastian Airport because the kit manufacturer was based there. Entering the landing pattern at Sebastian, he was positioned too high and fast for runway 13, but still in good position to enter a downwind to a left base leg for landing on runway 22. He was, however, more familiar with the characteristics of the constant speed propeller, and once he shut his engine off with his mixture control, he did not realize that the three bladed fixed pitch propeller would, "cause that much drag". When he realized he'd shut his engine off prematurely and tried to extend his glide, the pusher powered/canard configured airplane stalled and entered a "pitch-buck" condition. Initial impact was with a narrow road bed extending into a swamp, followed by about a 75-foot slide into the swamp. The airplane came to rest upright in about 2 feet of water. Subsequent examination of the engine by factory personnel revealed that a castellated nut securing the cockpit throttle cable linkage to a threaded connection on the fuel metering shaft of the fuel servo had backed off due to a missing cotter pin. This allowed the linkage to disconnect and resultant loss of cockpit engine power control.