On August 26, 2002, at 1855 eastern daylight time, a Cessna T210N, N4908C, was substantially damaged during a forced landing to a field in Glastonbury, Connecticut, following a partial loss of engine power. The certificated private pilot and the passenger were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight conducted under 14 CFR Part 91. In an initial interview, the pilot stated that the purpose of the flight was to practice instrument approaches at Hartford-Brainard Airport (HFD), Hartford, Connecticut. While performing the missed approach procedure of a second GPS Runway 02 approach, on a heading of 150 degrees, in a climb, about 2,000 feet, the pilot noticed a "decrease in power from the engine." He then declared an emergency, disengaged the autopilot, and performed a forced landing to a corn field. During the landing roll-out the nose gear separated, and the airplane nosed over. The pilot reported that in preparation for the emergency landing, he performed the items on the emergency checklist from memory. He "manipulated the throttle;" however, he did not observe a response from the engine. The pilot could not recall the indications from the engine instruments, manifold pressure gauge, or tachometer. He also could not comment on any specific sounds, or changes in sounds, coming from the engine. A witness on the ground observed the airplane flying at approximately 100 feet. He reported the engine was running and the wings were wobbling slightly. He had observed other aircraft flying low over this field in the past and so was unconcerned and diverted his attention. Less than ten seconds later, the witness heard the sounds of impact. The witness described the engine sound similar to an "old Ford Pinto" car engine. In a second interview, the pilot was questioned specifically about the operation of the autopilot during the accident flight. The pilot reported that he had been experiencing problems with the autopilot, and a replacement autopilot was installed for the accident flight to troubleshoot the problem. The pilot stated that during the flight, while the autopilot was engaged, the airplane "departed from its course" and "exaggerated its turns." Due to the autopilot causing the airplane to perform "erratically," the pilot disengaged it during the second approach. After the second approach, while performing the missed approach procedure, the pilot reengaged the autopilot, and the airplane initiated uncommanded turns and "sways". The pilot continued with the missed approach, and during the climb, the engine "died." As stated in his initial interview, the pilot reported that he then disengaged the autopilot and performed a forced landing to a field. The pilot added that the flight controls felt "heavy" during the descent, and their resistance to control inputs had increased. The pilot also recalled that he may have adjusted the electric trim to try to compensate for the resistance. After the accident, an examination of the airplane was conducted by a Federal Aviation Administration (FAA) inspector. According to the inspector, compression and valve train continuity were confirmed on the engine. The magnetos and ignition system were examined, and no deficiencies were noted. In addition, the airplane was fueled with 85 gallons of fuel prior to its departure; examination of the fuel system revealed no deficiencies and fuel was present in the fuel injection system. The induction and turbocharger systems were unobstructed; the turbocharger rotated freely. The elevator trim was observed in the full nose down position. Following the accident, the autopilot computer was removed and tested at an avionics repair station. The computer was tested for trim system runaway; all functions were found to work normally, in all positions, with no discrepancies. Examination of the airplane and engine logbooks revealed the last annual inspection was performed on February 20, 2002. Maintenance on the fuel system was performed just prior to the accident flight in order to check fuel pressure. Fuel pressure was adjusted to within specified limits. The maintenance facility performed a satisfactory run-up of the engine and returned the airplane to service. A test-run of the engine was conducted on November 6, 2002, under the supervision of an FAA inspector. The engine started immediately and ran without interruption at various power settings. No anomalies were noted.