On September 6, 2002, at 1345 eastern daylight time, a Cessna 172S, N827SP, registered to Skystead, Inc., and operated by a student pilot, collided with the ground shortly after takeoff from the Immokalee Airport in Immokalee, Florida The instructional flight was operated under the provisions of Title 14 CFR Part 91, and visual flight rules. Visual meteorological conditions prevailed and no flight plan was filed for the local training flight. The student pilot was not injured, and the airplane was substantially damaged. The training flight originated from Naples Municipal Airport in Naples, Florida, at 1200. According to the student pilot, she departed from runway 09, and at 300 feet above ground level she began "fighting with the yoke" of the airplane. The pilot stated that she adjusted the trim, but the "nose was up and the airplane was coming down". The engine was running and the airspeed was at 65 knots. The pilot decided to "quit fighting" because she knew the airplane was "going down". She squawked 7700 on the transponder, and prepared for a precautionary landing by closing the throttle. The student pilot selected a field in front of her, approximately two miles northeast of the departure end of runway 09. The airplane landed hard, with the nose wheel impacting the ground first, and slid across a wet pasture coming to rest in a pond. The pilot stated that the autopilot circuit breaker had been pulled prior to flight and the autopilot was disengaged. She also stated that she had observed the autopilot run through the preflight checks when electrical power was applied to the aircraft prior to departure. According to the student pilot, she had been instructed during her flight training to pull the circuit breaker prior to each solo flight and not to operate the autopilot at this stage of her training. The autopilot circuit breaker is located on the left side of the instrument panel, to the left of the control yoke and several inches above the landing light ON/OFF switch. Examination of the airplane revealed all of the circuit breakers were in the "IN" position. The nose landing gear collapsed aft and to the left, and the engine firewall was damage. The upper and left engine cowling were pulled away from the fuselage, and the left engine cowling was damaged. The elevator trim was found in a nose up position instead of the checklist specified takeoff position which is clearly marked on the elevator trim wheel. The propeller blades were bent moderately aft and the blade tips were slightly discolored. Although the engine was exposed to water, it was successfully started and idle was smooth at 650 rpm. The engine was successfully run up to approximately 2125 rpm. The autopilot computer installed on the airplane was a Bendix/King KC 140 Flight Control Computer, P/N 065-00176-7702. A series of tests were conducted to verify operation of the autopilot computer, autopilot circuit breaker, autopilot disconnect switch on the yoke, and the trim switch. The autopilot and its components operated normally during these tests. In a separate written statement, the student pilot stated that she "should have realized that it wasn't possible for the autopilot to be disengaged and still work". The operator has revised training to include more instruction on the use of the autopilot and procedures to handle inadvertent autopilot engagement.