On April 13, 2023, about 1330 central daylight time, a Junior Ace airplane, N5545, was substantially damaged when it was involved in an accident near Mammoth Springs, Arkansas. The pilot sustained fatal injuries. The airplane was operated as Title 14 Code of Federal Regulations Part 91 personal flight. The flight originated from the owner/pilot’s private airstrip in Ash Flat, Arkansas. The airstrip was about 16 miles from the accident location. Witnesses near the accident site reported that they observed the airplane circle over a rock quarry near Mammoth Springs. One witness observed the airplane dive into the quarry on its final pass and collide with a vertical rock wall. The accident site was in a rock quarry. Examination of the accident site showed that the airplane collided with the 75-ft rock wall. Impact marks showed that the airplane impacted the wall about 20 ft below the top of the wall. See Figure 1. Figure 1. Accident Site The damage to the airplane was consistent with a high-energy impact. Examinations of the airframe and engine did not reveal any preimpact mechanical anomalies that would have precluded normal operations. The Arkansas State Crime Laboratory, Little Rock, Arkansas, performed the pilot’s autopsy. According to the pilot’s autopsy report, his cause of death was multiple injuries, and his manner of death was suicide. Toxicological testing by the Federal Aviation Administration (FAA) Forensic Sciences Laboratory, Oklahoma City, Oklahoma, detected ethanol at 0.048g/dl, along with n-propanol, in cavity blood. Neither ethanol nor n-propanol was detected in vitreous fluid. Ethanol is the intoxicating alcohol in beer, wine, and liquor, and, if consumed, can impair judgment, psychomotor performance, cognition, and vigilance. Alcohol consumption is not the only possible source of ethanol in postmortem specimens. Ethanol may sometimes be produced by microbes in a person’s body after death, potentially elevating ethanol levels in some postmortem specimens but not others. Vitreous fluid is generally the specimen type best protected against postmortem microbial ethanol production. N-propanol can be produced by microbes in a person’s body after death. Detection of n-propanol in a postmortem specimen is potentially indicative of postmortem microbial activity in the specimen but does not necessarily mean that microbial activity produced ethanol.