HISTORY OF FLIGHTOn April 4, 2024, about 1633 central daylight time, a Davis DA-3 airplane, N88DT, was destroyed when it was involved in an accident near Antlers, Oklahoma. The pilot and two passengers were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. A witness reported having a brief conversation with the pilot between 1530 and 1600 at the Stan Stamper Municipal Airport (HHW), Hugo, Oklahoma. Afterward, the pilot departed in the accident airplane. The airplane seemed to perform normally, and nothing seemed out of the ordinary. A second witness observed the airplane arriving at the Antlers Municipal Airport (80F) between 1600 and 1630. Two men met the pilot, and they all boarded the airplane. The pilot subsequently departed toward the south. The takeoff seemed to be routine and there were no obvious anomalies with respect to the airplane. At 1633, local authorities received a report of an explosion. Upon arriving at the site, first responders observed the crashed airplane with an active fire. There were no known witnesses to the accident itself, and no ADS-B data related to the accident flight was located. The airplane came to rest adjacent to a large tree about 1.4 miles south-southwest of 80F. Multiple smaller trees and low brush were also present at the site. A post-impact fire consumed portions of the fuselage and charred the large tree. Low brush was burned over a large area surrounding the airplane. PERSONNEL INFORMATIONThe pilot’s logbook was not available for review. He reported 112 hours total flight experience at the time of his most recent medical certificate application in January 2022. He was issued a third-class airman medical certificate without limitations at that time. That medical certificate expired on January 31, 2024, and no subsequent medical certificate applications were on file. The pilot did not hold a valid medical certificate or BasicMed certification at the time of the accident. AIRCRAFT INFORMATIONThe previous owner of the airplane reported that the airplane’s handling qualities were excellent, noting that it was difficult to aerodynamically stall under normal conditions. The previous owner checked out the accident pilot when he bought the airplane and commented that he was “very good at low-speed maneuvering.” During that checkout flight, the pilot inadvertently turned off the fuel valve with his foot while they were on the ground. The previous owner reported that the airplane was comparable to a Cessna 150 but with better handling qualities. The airplane was placarded for 1,200 lbs maximum gross weight. The previous owner recommended not putting a third person in the airplane because it was underpowered. Maintenance records for the airplane were not available for review. AIRPORT INFORMATIONThe previous owner of the airplane reported that the airplane’s handling qualities were excellent, noting that it was difficult to aerodynamically stall under normal conditions. The previous owner checked out the accident pilot when he bought the airplane and commented that he was “very good at low-speed maneuvering.” During that checkout flight, the pilot inadvertently turned off the fuel valve with his foot while they were on the ground. The previous owner reported that the airplane was comparable to a Cessna 150 but with better handling qualities. The airplane was placarded for 1,200 lbs maximum gross weight. The previous owner recommended not putting a third person in the airplane because it was underpowered. Maintenance records for the airplane were not available for review. WRECKAGE AND IMPACT INFORMATIONThe airplane exhibited impact and postimpact fire damage. The forward section of the fuselage and portions of both wings were consumed. Both wings were separated near the wing roots and rested adjacent to the fuselage. The fracture surfaces appeared consistent with overstress. The flight controls remained attached to the airframe, and control continuity was confirmed from each control surface to the cockpit area. The engine was separated from the airframe and rested inverted on the ground near the fuselage. It exhibited localized impact damage. The entire engine was discolored, and an area of the accessory case was consumed, consistent with the postimpact fire. An on-scene examination, which included borescope examination of the cylinders, did not identify any anomalies consistent with a preimpact failure or malfunction; however, the examination was limited by the extent of the fire damage. The propeller shaft extension from the propeller to the engine was intact, and the bolts were secure and safety wire was properly installed. The propeller was not observed; however, the retaining plates and propeller attachment bolts appeared to be intact and undamaged. MEDICAL AND PATHOLOGICAL INFORMATIONThe Office of the Chief Medical Examiner in Tulsa, Oklahoma, performed an autopsy of the pilot. The cause of death was attributed to multiple blunt force injuries sustained in the accident. The autopsy noted the presence of coronary artery disease including approximately 60-70% narrowing of the right coronary artery and 10-20% narrowing of the left anterior descending coronary artery by plaque. Visual examination of the heart did not identify other significant disease. Toxicology testing was performed at the FAA Forensic Sciences Laboratory. Diphenhydramine was detected in heart blood and in liver tissue; however, no specific levels were reported. Norchlorcyclizine was detected at a low level in heart blood and at 53 ng/g in liver tissue. Diphenhydramine is a sedating antihistamine medication widely available over the counter in multiple sleep aids and cold and allergy products. Diphenhydramine can cause cognitive and psychomotor slowing and drowsiness, and often carries a warning about driving and operating machinery. Diphenhydramine has significant potential for postmortem redistribution. Norchlorcyclizine is a metabolite of the antihistamine medications chlorcyclizine, hydroxyzine, and meclizine, and may be an impurity in some formulations of the antihistamine medication cetirizine. Although those medications may have sedating or impairing effects, none of those medications were detected in this case. Norchlorcyclizine itself has not been established to have impairing effects.