American Champion Aircraft 8KCAB accident near Marengo, Wisconsin, October 23, 2021

The NTSB's narrative final · quoted from the NTSB record

The pilot and passenger were conducting a personal flight. The pilot’s sister-in-law received a phone call from the pilot about 5 minutes before the accident, during which the pilot told her to wait outside because he intended to fly over her house. The airplane then overflew her position multiple times at a low altitude before she saw the airplane “doing a loop” shortly before it descended into terrain. Another witness saw the airplane flying “pretty low” about 200 - 400 ft above the ground. The witness stated that the airplane dove toward the ground while flying to the west before it “went back up going upside down” while flying to the south. The airplane then descended and crashed in a residential yard while flying north. Based on video footage, the pilot completed several low passes and steep turns while flying near his sister-in-law’s house; there was no video evidence that the pilot attempted an aerobatic loop maneuver. Further review of on-board video footage indicated the airplane’s bank angle exceeded 80° left-wing-down, and the stall warning horn was audible in the seconds before the accident. Another video, captured by the pilot’s sister-in-law on the ground, showed the airplane in a steep nose-down descent in the moments before the accident. Based on the available information, it is likely that the pilot did not maintain adequate airspeed during a steep turn, which resulted in the airplane exceeding its critical angle of attack and an inadvertent aerodynamic stall at a low altitude. The low altitude at which the aerodynamic stall occurred likely prevented a successful recovery. Postaccident examination of the airplane and engine revealed no evidence of a preexisting mechanical malfunction or failure that would have prevented normal operation of the airplane. Although the pilot’s autopsy revealed he had acute myocarditis, likely due to COVID-19, there was no evidence of impairment based on the on-board video footage. Additionally, toxicological testing did not reveal any impairing substances.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.