On May 7, 2010, about 1511 eastern daylight time, an experimental amateur-built Swezey/Molinar Vans RV-10, N110TD, was destroyed during an explosion after landing at Ridgeland Airport (3J1), Ridgeland, South Carolina. The certificated private pilot and passenger were seriously injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight, which was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to the pilot, earlier in the day he fueled the airplane with automotive fuel which contained 10 percent alcohol, flew to Athens/Ben Epps Airport (AHN), Athens, Georgia, picked up his passenger and then departed from AHN about 1400. The flight was flown at an altitude of 9,500 feet above mean sea level and everything "seemed normal." While the airplane was on short final, "about 200 feet from the runway," he had a "brief whiff" of an odor similar to "a gas smell." Upon landing, the passenger asked if they should open the door and the pilot stated "wait [un]til we clear the runway." The airplane back taxied on the runway a short distance and then exited the runway on the taxiway adjacent to the ramp area. As the airplane exited the runway, an explosion caused the windows and door to be blown out. He stated that it was similar to a "vapor fire" in that there was an intense flash of heat and fire; however, it did not last long. The occupants exited the airplane. The pilot returned to the airplane, utilized the on board hand held fire extinguisher, and extinguished the fire on the floor of the cabin. As he was walking away from the airplane towards his passenger, the airplane "exploded" a second time and was engulfed in flames. According to the co-owner of the airplane, it was inspected on January 2, 2010, and the "tunnel" for the fuel line was inspected and free of debris. He stated that normally they use "93 octane auto fuel;" however, they can use 100 LL aviation fuel. He further stated that he had flown the airplane about 2 or 3 weeks prior to the accident and did not detect any odors. Examination of the airplane by a Federal Aviation Administration (FAA) aviation safety inspector revealed that the airplane was completely consumed by fire. Only a small portion of the tail section and the engine area forward of the firewall had not been consumed by fire. The pilot held a private pilot certificate with a rating for airplane single-engine land and a repair man experimental aircraft builder certificate with inspection certificate for the accident airplane. The pilot's most recent FAA third-class medical certificate was issued in April 2009. He reported approximately 300 total hours of flight experience and approximately 135 total hours of flight experience in the accident airplane. He further reported that his logbook was in the airplane at the time of the accident. According to FAA records, the airplane was manufactured and issued a special airworthiness certificate in 2008. The airplane was equipped with a Chevrolet 2006 LS-2 engine and a Vesta 3B78 propeller. The pilot reported to the Safety Board investigator that prior to the accident flight, the airplane had accrued 150 total hours time in service. The 1456 recorded weather at Beaufort Marine Corp Air Station (NBC), Beaufort, South Carolina, located 14 nautical miles to the east of the accident location, included winds from 140 degrees at 5 knots, visibility 7 miles, few clouds at 6,000 feet above ground level, temperature 32 degrees C, dew point 16 degrees C, and the altimeter setting was 29.98 inches of mercury. According to documentation provided by the kit manufacturer, the airplane was designed to have an IO-540 Lycoming engine. Section 37, "Fuel System" provides a note that states in part "all fuel lines created in this section are made from ATO-035X3/8," which are soft aluminum tubing. The documentation further provides guidance to the builder on flaring the ends of the fuel line in order to connect the associated parts. A photograph provided by the FAA revealed that the fuel pump had automotive type rubber hoses and quick clamps to attach the hoses to right angle fittings. According to documentation provided by the kit manufacturer, the fuel selector valve, fuel pump, and fuel lines were located in the center of the fuselage between the seats, forward of the main spar carry through. The flap motor and actuator was also located in the center of the fuselage but aft of the main spar carry through near the aft passenger seats, approximately 20 inches from the fuel selector valve. The pilot reported that he normally "raises the flaps after clearing the runway;" however, could not recall if he had raised the flaps just prior to the first explosion.