On August 22, 1993, about 1230 CDT, an experimental homebuilt Wells Pitts S-2-S airplane, N10T, registered and piloted by commercially certificated, Charles S. Wells of Springfield, Illinois, was performing aerobatic maneuvers during an air show at Bloomington-Normal Airport, Bloomington, Illinois. While attempting a recovery from a maneuver the aircraft descended into the terrain. The aircraft was destroyed and the pilot sustained fatal injuries. This flight was operating under a waiver to 14 CFR 91. No flight plan was filed and visual meteorological conditions prevailed at the time of the occurrence. The flight originated from Bloomington, Illinois. Witnesses reported that N10T exited a lomcevak into an inverted flat spin "...too low for possibility of recovery." The aircraft impacted the terrain nose down at approximately 45 degrees. Toxicological testing found no carbon monoxide, cyanide, volatiles or drugs. An autopsy revealed no pre-existing abnormalities which would have inhibited the pilot's normal flying ability. The autopsy was performed at McLean County Coroner's Office, Bloomington, Illinois. Post-accident investigation of the aircraft found no evidence of pre-impact mechanical malfunction.