On October 5, 1996, at 0930 central daylight time, a Cessna 172M, N172JF, was substantially damaged following a loss of control while on takeoff roll from a private airstrip near Tuttle, Oklahoma. The airplane, owned and operated by a private owner, was being operated under Tittle 14 CFR Part 91. The private pilot and the 3 passengers were not injured. Visual meteorological conditions prevailed for the local personal flight for which a flight plan was not filed. The flight departed from the Wiley Post Airport, near Bethany, Oklahoma, at approximately 0830. According to the pilot, the rented airplane had been "cruising at about 1,200 feet AGL in the local area for about an hour when the engine began to run rough." After circling the field, the pilot elected to execute a precautionary landing at the Thompson private airstrip near Tuttle, Oklahoma, where an ultralight fly-in was underway. The pilot added that while landing to the south, the airplane's spinner impacted a power line; however, he managed to land without further incident. After landing and clearing the 2,300 foot sod runway, the pilot checked the airplane for damage. He only found incidental damage to the propeller spinner. After inspecting the engine and completing a full engine runup, the pilot concluded that the rough running engine was "probably the result of carburetor icing" and he elected to depart the airstrip to the south and return to the Wiley Post Airport. The airstrip has a slight up slope when taking off to the south. The pilot stated that as the airplane approached rotation speed during the takeoff roll, the aircraft started to veer to the left and he was unable to maintain directional control "after applying full opposite rudder." Subsequently, the airplane veered off the left side of the runway impacting fence posts and trees. On the enclosed pilot/operator report, the pilot reported that the winds at the time of the accident were from 180 degrees at 12 knots. Examination of the airplane by the FAA inspector at the accident site revealed that the left main landing gear separated from the airframe, the left lift strut was bent and the outer portion of the left wing sustained structural damage. Post-recovery examination of the airframe by the operator and the FAA inspector confirmed flight control continuity to the rudder, elevators, ailerons. Additionally, no anomalies were found with the nose wheel steering mechanism or brake system. Witnesses at the airstrip provided the following information. The pilot attempted to take off with the wing flaps in the retracted (up) position. One witness stated that "in his opinion, the airplane assumed an exaggerated nose high attitude early during the takeoff roll and the pilot might have tried to pull the airplane off the ground prior to attaining flying speed." An ultralight pilot stated that the grass along the edges of the airstrip was "long enough to drag the wheel down." An estimate of the weight of the airplane at the time of the accident places the airplane within its limits. The person who last refueled the airplane stated that both fuel tanks had been topped off to within a 1.5 inches from the top of the filler neck.