HISTORY OF FLIGHTOn March 11, 2017, about 1030, Pacific standard time, a Challenger II light-sport airplane, N2621T, landed on the runway safety area (RSA) near the approach end of runway 10 and subsequently impacted a vehicle at the Oakdale Municipal Airport (O27), Oakdale, California. The commercial pilot was fatally injured and the airplane sustained substantial damage. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed near the airport and no flight plan was filed for the local flight. According to the airport caretaker, the pilot left his hangar door open, departed from runway 10 and entered the left traffic pattern. He stated that he heard the airplane on the downwind leg and that he did not see the airplane on the final approach or landing but heard an explosion. He subsequently responded to the accident site where a postimpact fire had ensued. A second witness, who was outside her house when she heard the airplane overhead, stated that she is often outside and hears airplanes pass over her house, which is below the downwind leg of the traffic pattern. She said that the accident airplane sounded different, which was what brought it to her attention. She did not witness the accident sequence. A third witness, who was at his residence, where he lived for over 50 years, stated that he heard an airplane performing several takeoffs and landings. During the last landing, he heard the airplane's wheels contact the ground, the engine advanced to full power, and then an explosion. Subsequently, he saw fire at the accident site, about 800 ft south of his location. He said that the engine sounded normal during the flight. Examination of the accident site revealed that the airplane touched down left of the approach end of the runway in the runway safety area (RSA), and left 200-ft-long tire tracks in the dirt and gravel. The tracks veered left toward the visual approach slope indicator, where the left turn increased. The tracks continued toward the taxiway into a grassy area in front of the pilot's hangar. The two tracks, the right larger than the left, continued 20 ft into low vegetation and then another 30 ft and ended near the pilot's truck. The airplane came to rest along the truck's left side. The airplane and truck sustained impact and fire damage. See figure 1 for an aerial view of the accident site. Figure 1. Aerial View of the Accident Site PERSONNEL INFORMATIONThe 78-year-old pilot held a commercial pilot and flight instructor certificates, with airplane single-engine land airplane ratings. His most recent Federal Aviation Administration (FAA) second-class airman medical certificate was issued on June 29, 2013, with the limitation that he must wear corrective lenses. Although his medical certificate was expired, it was not required when flying the accident airplane. The pilot reported on the medical certificate application that he had accumulated 1,800 hours of flight time, 8 hours of which were in the last 6 months. The pilot's last logbook entry, on November 30, 2016 showed that he had accumulated 1,977.2 total hours of flight time. The pilot had his check-out flight in the accident airplane on September 28, 2016, and had three more flights in the accident airplane the following November, which totaled 6 hours. AIRCRAFT INFORMATIONThe two-seat, high-wing, tricycle-gear airplane, serial number CH2-0199-CW-1838 was manufactured in 1999. It was powered by a 50-horsepower Rotax 582 Model 99 engine. The airplane was also equipped with a three-bladed fixed-pitch propeller. METEOROLOGICAL INFORMATIONAt 0953, Modesto Municipal Airport, Modesto, California, located 11 miles southwest of the accident site, reported wind 90° at 4 knots, visibility hazy, clear sky, temperature 17°C, dew point 14°C, and an altimeter setting 30.16 inches of mercury. AIRPORT INFORMATIONThe two-seat, high-wing, tricycle-gear airplane, serial number CH2-0199-CW-1838 was manufactured in 1999. It was powered by a 50-horsepower Rotax 582 Model 99 engine. The airplane was also equipped with a three-bladed fixed-pitch propeller. WRECKAGE AND IMPACT INFORMATIONThe examination of the wreckage revealed that the wings and cabin area were substantially damaged by postimpact fire. The left wing had separated from the airplane and was mostly consumed by post-impact fire; only the inboard trailing edge structural tubing and inboard section of the flaperon remained. The right wing remained attached to the airplane and exhibited thermal damage. The empennage remained intact, and flight control continuity was established through an elevator control tube and rudder control cables that were separated near the cabin area. The fuel tank had separated and was found near the main wreckage partially consumed by fire. The engine was found loose from its mount near the pilot seat and exhibited excessive thermal damage to the cylinder head and attached accessories. The propeller drive belt exhibited thermal damage, and belt remnants remained on both drive gears. Two propeller blades were found about a hundred ft from the main wreckage and propeller strike damage was found near the engine mount. The engine and its components revealed no mechanical anomalies. Seat belt hardware was found, and the buckles were found unfastened. MEDICAL AND PATHOLOGICAL INFORMATIONThe Stanislaus County Sheriff's Office, Modesto, California, conducted an autopsy on the pilot. The pilot's cause of death was reported as "flash-fire burn with acute soot and smoke inhalation." The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology on specimens from the pilot. The tests were negative for carbon monoxide, cyanide and volatiles. The testing detected 13.6 ug/ml of acetaminophen (also known as Tylenol) in urine, which is a nonimpairing pain reliever.