20020906023989A

.19) On September 6, 2002, at 1345 eastern daylight time, a Cessna 172S, n 827SP, registered to skystead, inc., and operated by the student pilot collide 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 sustained substantial damage. The flight originated from naples municipal airport in naples, Florida, at 1200. According to the student pilot, she took off from runway 09. Approximately 300 feet above ground level, the airplane pitched up. The student pilot pushed the yoke forward and adjusted the trim but the airplanes nose was up and the airplane was descending. The engine was running and the airplane was going about 65 knots. The airplane impacted the ground and the nose wheel plowed through dirt before coming to a stop. She shut down the airplane and waited for the local sheriff's department helicopter to arrive. Examination of the airplane found the trim tab in the full nose down ppsition. The airplane has been recovered for further examination. (-23) student plt departed naples FL (apf) on a VFR student xc trng flt destined for immokolee FL (imm) for the purpose of to & ldg practice. Nearing imm, student observed rain in the area and elected to perform a full stop ldg and wait for the wx to improve. While at imm, she chked wx for imm and apf. After about a 10 minute down time on the grnd at imm, she decided the wx was conducive for a safe return flt to apf. After becoming airborne, the plt observed more wx in the direction of her indended route of flt toward apf. The plt elected to return to imm for a ldg in ordr to wait for wx improvmnt. After again chking wx,she decided to depart once again for apf. During her preflt chk of the acft, the plt foundthe plt's seat belt was jammed, and asked FBO persnl to fix her seat belt after this was completed, she took off again for the return trip to apf. The plt stated the surface winds at the time of take off was 100 degs at 10 knts, therefore she took off from rwy 9. She said that wxd was not a factor in this accident, and that the air was smooth. As she passed through approx 300 ft, she noticed that she was pulling back against the control yoke which was attempting to pull forward, contrary to her control input. She said that at no time was the acft attempting to roll, or chg direction, only that the acft was descending straight ahead. At approx 500 feet, this anormaly with the yoke continued and the acft was de scending, so the plt declared an emerg on the txpdr and radio. She stated that she finally "quit fighting, because she knew she was going down." She said she closed the throttle and performed a forced ldg in a marshy area. During the forced ldg sequence in the muck, the nose ldg gear collapsed. After the acft came to rest in a nose down attitude, the plt continued her attempts to establish radio contact miami center on 121.5 to advise that she had crashed off the rwy at imm. The plt claimed that she had observed the a/p run through the preflt chks when electrical power was applied to the acft prepatory to flt, even though the curcut breaker (c/b) had been pulled. An insp of the acft at imm by FAA persnl, including an FAA avionics insp, members of the acft and eng mfgr, revealed no evidence of any preimpact failure or malfunction of the acft or any of its components. The curcuit breaker for the a/p was found in the "in" position, thereby allowing power to the a/p. although the prop was bent on impact a test run of the engine was performed on the acft and 2125 static RPM was developed while the acft was stationery, in spite of the bent propeller. The fuel system was checked for quanity, and the tanks were determined to be nearly full. The fuel was examined for comtainates and none was found. Flight control and trim tab functions were checked, and were observed to operate normally. The acft recovery team had disconnected the aileron flt control cables an electrical wiring in the wings in preparation for the acft to be transported back to apf, thereby rendering the aileron servos inoperative. The a/p was otherwise test functioned and it was determined to be operating normally. The a/p c/b was pulled, power was interuppted to the a/p when the c/b was pushed in, or reset, power was restored to the a/p and a/p operation was observed. The operation of the c/b and a/p was repeatedly checked in excess of 10 times, and no evidence of any malfunction of the c/b or the a/p was discerned. The plt's CFI stated that this student had required approx 50 hours of trng before he was able to solo her. The plt stated that her CFI had cautioned her not to use the auto plt (a/p) at her stage of trng, that she had enought to do without the addtnl burden of operating the a/p. she stated that her CFI had told her to keep the a/p curcuit breaker pulled so the a/p would not operate. Based on the plt's stmts, the evidence, the stmts of the owner of the acft and the plt's CFI, and the post crash testing of the various components, itis the conclusion that the pilot unknowingly engaged the a/p, and failed to notice the c/b was engaged on the a/p prior to take off. The uncommanded operation of the a/p produced counter control input by the plt that lead to bewilderment in the cockpit at a critical phase of flt, immediately after take off. Operator has revised trng to include more instruction on a/p, expecially procedures to cope with inadvertant a/p engagement. Addntl info may be obtained from NTSB acc rept #ATL02LA166.