On September 28, 1999, about 1122 eastern daylight time, a Grumman American AA-1B, N9908L, registered to a private owner, operated as a 14 CFR Part 91 personal flight, made a hard landing at Dunnellon, Florida. Visual meteorological conditions prevailed at the time, and no flight plan was filed. The airplane was substantially damaged and the private-rated pilot received serious injuries. The flight originated from Crystal River, Florida, the same day, about 1100. The pilot stated that during his landing attempt he experienced a series of bounces. The pilot further stated that his recovery attempts were unsuccessful, and the aircraft incurrred substantial structural damage. The FAA inspector who conducted a postcrash examination of the airplane stated that he found no evidence of any precrash mechanical malfunction.