On June 26, 1997, at 1845 mountain daylight time, a RANS S-12 Airaile ultralight, N2117X, collided with the ground in an uncontrolled descent following initial climb during takeoff. The private pilot received serious injuries and the aircraft sustained substantial damage. Visual meteorological conditions prevailed for this local flight which originated approximately one minute prior to the accident. No flight plan was filed. According to the owner, this was the pilot's first solo flight in this aircraft and according to the pilot he had spent approximately 6 hours of dual flying with the owner. According to the pilot, his engine run up was normal and he became airborne at 30 to 40 miles per hour (mph). He said it is normal for this aircraft to climb steeply but he was unable to get the nose down following takeoff even though he applied full nose down elevator. Also, according to his account, the aircraft pulled to the right and as the speed decreased the right pulling tendency increased in magnitude. The pilot stated the aircraft pitched to a vertical nose down attitude somewhere between 50 and 100 feet above the ground and descended to a vertical impact. He also said he is 30 to 40 pounds lighter than the person who normally flies this aircraft solo. Following the accident, examination of the aircraft by this investigator provided evidence that the right lift strut support cable was detached at the upper fitting. The pin was present and the pin mounting showed no evidence of damage or distortion. Examination also provided evidence that control continuity was present and that the elevator trim was found in the neutral position. The fuselage was crushed up and back and both wings exhibited upward deformation with crushing in a upward direction toward the tip. A witness, who is a certified flight instructor, provided information that following takeoff, the nose of the aircraft continued to rise and it appeared to him like the aircraft stalled and rolled right after the stall. He said the nose went down to the vertical and the aircraft remained in that attitude until impact. He also said the elevator appeared to be deflected to the full nose down position prior to the stall. The owner of the aircraft could not provide specific performance or weight and balance information but stated the center of gravity tended to be "somewhat" forward with lighter weight in the cockpit.