On August 18, 1998, at 1700 central daylight time, an Aero Commander S2R agricultural airplane, N1731S, registered to a private individual and operated by Rebel Flyers, Inc., of Bulverde, Texas, was substantially damaged during takeoff from the Beeville Municipal Airport near Beeville, Texas. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations (CFR) Part 91 positioning flight. The airline transport rated pilot, sole occupant of the airplane, was seriously injured. The flight was originating at the time of the accident with a destination of Victoria, Texas. Witnesses reported to the FAA inspector that during takeoff from runway 18, the airplane lifted off the runway after rolling for about 1,000 feet. It appeared that the airplane was about 4 to 5 feet above the runway when the right wing dipped downward and then leveled. The airplane's nose pitched up and the airplane veered to the right. The right wing dipped again, and the airplane turned right, nosed down and impacted the ground. According to a witness the engine was running; however, the propeller "sounded as though it was not producing full power." The owner reported in the Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2, that the airplane's run-up was "normal." The owner further reported that during takeoff, the airplane lifted off the runway after a ground roll of about 800 feet. The right wing appeared to drop slightly, then the airplane suddenly went "straight up with both tops of wings showing and began [a] sharp right turn." The airplane's altitude was not more than 75-100 feet agl. The owner stated that the "aircraft was checked thoroughly" prior to the flight since it had not flown in two weeks. The owner indicated on the Form 6120.1/2 that there was no "Mechanical Malfunction Failure." An examination of the airplane by the FAA inspector revealed that the throttle, mixture, and propeller controls were found in the "back position." Further examination revealed that the fuselage was twisted. Both wings, the firewall and engine were damaged.