On October 18, 2003, about 1230 central daylight time, an experimental amateur-built Oostdik M-18-X, N53TW, collided with trees while taking off to the south on a private airstrip (1,600 foot long, grass) in Pana, Illinois. The private pilot was seriously injured. The airplane was substantially damaged. The 14 CFR Part 91 personal flight was operating in visual meteorological conditions without a flight plan. The flight was originating at the time of the accident with an intended destination of Taylorville, Illinois. The pilot stated he began his takeoff roll and lifted off about 50 miles per hour. The pilot stated that during initial climb he noticed his brother standing by a nearby hangar. The pilot "waved" to his brother, and only remembers hearing tree limbs hitting the airplane before the airplane impacted the terrain.