On October 31, 2021, about 0937 central daylight time, a Cessna 150L airplane, N6713G, was substantially damaged when it was involved in an accident near Forrest City, Arkansas. The pilot was fatally injured, and the passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the passenger, there were no issues found with the airplane during the preflight inspection and the airplane was running well. When the airplane touched down on runway 36, the pilot pushed the yoke forward to lower the nose landing gear to the runway surface. After the nose landing gear touched down the airplane veered to the left and exited the runway surface. The pilot asked the passenger if he was on the rudder pedals, to which the passenger stated that he was not. The airplane struck a fence and came to rest upright. The passenger observed the pilot outside of the airplane near the right main landing gear. According to the passenger, the pilot never liked wearing his seat restraints. The passenger, seated in the left seat, was wearing the installed 3-point restraint system. The pilot, seated in the right seat, was not wearing the installed restraint system. He was ejected from the airplane and was fatally injured. Wheel mark impressions were visible in the grass beginning next to the runway. The main wheel marks continued through the grass for about 650 ft to the accident site. The grass area alongside the runway was about 120 ft wide between the runway and the airport perimeter fence. The wheel marks in the grass gradually curved to the left for about 100 ft before they began to curve back to the right and then nearly parallel to the airport perimeter fence. About 400 ft from the point where the airplane left the runway, the main wheel marks could be seen in the grass, but the nose wheel mark was no longer visible. A series of deep gouges in the grass were observed. The tail tie down hook was found packed with mud and grass. Flight control continuity was established from the ailerons to the control column. Elevator control continuity was established from the forward spar to the control surfaces. Examination of the airframe and engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation of the airplane. Examination of the main landing gear and associated brake assemblies did not reveal any pre-impact anomalies. Postaccident examination of the airplane revealed that the airplane was in poor mechanical condition. The aft elevator bellcrank was severely corroded and the bearing exhibited a rough or ratchet-type movement. An insect nest was observed inside the separated aileron piece. The rudder stop-bolts and associated hardware appeared to be the original size and were severely corroded. The elevator trim actuator chain remained engaged on the actuator sprocket. The chain appeared dry and corroded. There did not appear to be fresh grease on any chains, pulleys, or hinges. The airplane paint was faded and peeling. Bird feces covered the airframe and engine, and insect nests were found in the cabin, wings, and tail cone. All exposed hardware on the airplane was severely corroded. Neither the pilot logbooks nor the airplane maintenance records were available for review during the investigation. The pilot’s most recent FAA medical examination was on February 17, 1993. At that time, the pilot reported civil flight experience of 130 total hours. An autopsy of the pilot was performed by the Arkansas State Crime Laboratory Medical Examiner. According to the autopsy report, the cause of death was multiple injuries, and the manner of death was accident. The FAA Forensic Sciences laboratory performed toxicological testing of postmortem specimens from the pilot. This testing detected diphenhydramine at 269 ng/mL in heart blood. Diphenhydramine was also detected in urine. 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. It often carries a warning that it may impair performance of tasks like driving and operating heavy machinery. The FAA states that pilots should not fly within 60 hours of using diphenhydramine to allow time for it to be cleared from circulation.