On September 11, 2004, at 1025 central daylight time, N49RT, an experimental Wood Thorpe T-18 tail wheel equipped airplane, registered to and operated by a private pilot, collided with a tree following a loss of directional control during landing at Olive Branch Airport, Olive Branch, Mississippi. The personal flight was conducted under Title 14 CFR Part 91, and visual flight rules. Visual meteorological conditions prevailed at the time of the accident and no flight plan was filed. The private pilot and pilot-rated passenger were not injured and the airplane sustained substantial damage. The flight originated at Olive Branch Airport, on September 11, 2004, at 0915. According to the pilot, he had purchased the airplane the same day of the accident and was flying with the previous owner for purposes of familiarization of operations of the airplane. He stated that several take-offs and landings were completed successfully. He stated that on the accident landing, he landed the airplane on the runway centerline and the airplane suddenly veered to the left of the runway centerline, and then veered right "uncontrollably" and departed the runway surface, traveled down an embankment, the right wing collided with a tree, and the airplane came to rest in a ditch. According to the pilot-rated passenger, the pilot had performed three or four landings. The passenger stated that on the accident landing, "a normal three-point landing was accomplished" by the pilot. He stated the airplane veered to the left side of the runway and "appeared to lift-up." He stated the airplane then veered to the right side of the runway, departed the runway surface, traveled down an embankment, turned right 180 degrees, and came to rest in a ditch at the bottom of the embankment. He stated that he then shut off electrical equipment and engine power. Examination of the wreckage site revealed tire skid marks that began 1600 feet from the threshold of runway 36 and extended to the left side of the runway. At 2000 feet from the threshold, the tire marks departed the left side of the runway surface into the grass for approximately 20 feet before turning back toward the runway surface. Tire skid marks were observed from the grass, heading right (east) across the runway surface, and then departed the right side of runway 36 at 2200 feet from the threshold. The airplane came to rest in a ditch on a southerly heading abeam 2500 feet from the runway 36 threshold. Examination of the wreckage revealed that the right wing spar was bent, the left main gear was twisted aft, and the empennage was crushed. Both of the propeller blades were bent aft.