CEN21FA327

The pilot departed on a personal flight, and the wreckage was located about 20 nautical miles from the departure airport by the property owner. There were no witnesses to the accident. Recorded data showed that, after maneuvering over the area of the accident site for about 6 minutes, the airplane entered a near-vertical descent. The airplane impacted terrain and was destroyed. The wreckage was consistent with a wings-level, near-vertical impact. Postaccident examination revealed no mechanical anomalies that would have precluded normal operation. Toxicology testing of the pilot identified ethanol. The large discrepancy among the ethanol levels in muscle, heart, and liver indicates that at least some of the detected ethanol was likely from sources other than consumption. Notably, the severity of injury made postmortem microbial ethanol production more likely, and the detectable n-propanol and n-butanol in muscle and heart indicate likely postmortem microbial activity in these tissues (although such activity does not always produce ethanol). Although at least some of the detected ethanol was likely from sources other than consumption, the available ethanol results are insufficient to exclude the possibility that consumed ethanol may have exerted impairing effects on the pilot, particularly given that diphenhydramine was also detected. Like ethanol, diphenhydramine may exert impairing sedative effects, and such effects may combine with those of ethanol. There is insufficient medical and operational evidence to determine whether ethanol or diphenhydramine caused impairment that contributed to the accident.

Download of data from the pilot’s watch indicated that he was maneuvering the airplane near the accident site for about 6 minutes before the airplane entered a steep descent over the accident site. On July 18, 2021, about 2040 central daylight time, a Luscombe 8F, N2054B, was destroyed when it was involved in an accident near Comstock, Texas. The commercial pilot sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The airplane departed from Del Rio International Airport (DRT), Del Rio, Texas, about 2015. The wreckage was found by a landowner while he was checking the field’s fence; he did not hear or see the accident. There were no known witnesses to the accident. The pilot’s most recent third-class Federal Aviation Administration medical certificate was issued on December 27, 2006. At that time, he reported no medication use and no active medical conditions. The Webb County Medical Examiner's Office, Laredo, Texas, performed the pilot’s autopsy. According to the autopsy report, the cause of death was multiple traumatic injuries, and the manner of death was accident. The autopsy was limited by the severity of injuries, with no major heart or brain structures described. Within this limitation, the autopsy did not identify significant natural disease. Toxicological testing at the FAA Forensic Sciences Laboratory detected ethanol in muscle at 0.182 g/dL, in heart at 0.065 g/dL, and in liver at 0.034 g/dL. Ethanol testing in brain was inconclusive. N propanol and n-butanol were detected in muscle and heart. Diphenhydramine was detected in muscle and liver. Ethanol is the intoxicating alcohol in beer, wine, and liquor. It can impair judgment, psychomotor performance, cognition, and vigilance. FAA regulation imposes strict limits on flying after consuming ethanol. This includes a prohibition on acting as a crewmember of a civil aircraft while having a blood ethanol level of 0.04 g/dL or greater. Ethanol can also be produced by microbes in a person’s body tissues after death. N-propanol and n-butanol are other alcohols that can be produced by microbes in a person’s body tissues after death. Diphenhydramine is a sedating antihistamine available over the counter in multiple cold and allergy products as well as sleep aids. Diphenhydramine can cause drowsiness and cognitive and psychomotor impairment. It typically carries a warning to be cautious with tasks like driving and operating machinery, and to avoid use with alcohol, which can increase its sedative effects. The FAA states that pilots should not fly within 60 hours of using diphenhydramine, to allow time for it to be eliminated from circulation. The pilot was a United States Air Force pilot. He accumulated a total military flight experience of 2,084 hours, and his total civilian flight time was 717 hours as of his most recent logbook entry, dated September 2, 2018. The wreckage was located about 20 miles north-northwest of DRT. Theairplane came to rest inverted on a magnetic heading of 202o. The propeller, located several feet forward of the nose, exhibited chordwise scratching consistent with rotation. The propeller hub was split in half, consistent with impact damage. Ground scarring was limited to the areas under the propeller and the airframe. There was no ground scarring across the field. The airplane exhibited substantial damage to the fuselage, wings, and empennage. The crush damage to the nose and both wings was consistent with a wings-level, nearly vertical impact angle. All control surfaces were located with the fuselage at the accident site. Both wing flaps were retracted. Postaccident examination of the airplane confirmed continuity each of the flight control surfaces to the cockpit controls. All separations in the control system were consistent with overstress due to impact forces. The engine crankcase was broken open. The internal engine components did not exhibit failure. The tachometer gauge needle was deformed along the tachometer face. The tachometer indicated about 2,600 rpm.