The pilot departed on runway 18 in a special light sport airplane, with his grandson onboard. The turf runway was 2,313-feet-long by 50-feet- wide, and sloped down toward the middle, with sandy, soft soil. The recorded wind at an airport located 9 miles west of the accident airport, about the time of the accident, was from 150 degrees at 4 knots. The airplane weighed about 1,250 pounds at the time of departure; less than the maximum gross weight of 1,320 pounds. A witness stated that the pilot attempted to rotate and climb, but did not lower the airplane’s pitch attitude to gain airspeed in ground effect. The airplane contacted the ground once, about 1,600 feet, and again about 2,500 feet from the point of initial takeoff. According to the witness, the pilot continued his takeoff roll and wallowed in ground effect. The right wing of the airplane impacted a tree, approximately 15 feet above ground level and the airplane came to rest inverted. A postcrash fire subsequently consumed the airplane. The pilot also reported that the engine was operating properly and that there were no preimpact mechanical failures or malfunctions. When asked how this accident could have been prevented, the pilot stated that he should have aborted the takeoff when he initially touched down on the soft soil.