On December 11, 2005, approximately 1450 Pacific standard time, a Hitchens EDI 90FT (Wheeler Express), N900EH, contacted the terrain after a loss of control while on VFR final approach to Chehalis-Centralia Airport, Chehalis, Washington. The commercial pilot, who was the sole occupant, received serious injuries, and the aircraft, which was owned by Charles B. Hitchens, of Lewisville, Texas, was substantially damaged. The 14 CFR Part 91 personal pleasure flight, which departed Olympia Regional Airport, Olympia, Washington, about 1330, was being operated in visual meteorological conditions. No flight plan had been filed. There was no report of an ELT activation. According to pilots at or near the Chehalis airport, the pilot of N900EH transmitted on the common traffic advisory frequency (CTAF) to advise those in the area that he was inbound on a VFR GPS straight-in approach to runway 16 at Chehalis. At no time did he mention anything about having a problem with either the aircraft or himself. When the aircraft was about one-half mile north of the approach end of Runway 16, a number of witnesses who were near or on the airport heard what sounded to them like an aircraft's engine increasing to a very high rpm. When they looked in the direction from which the sound came, they saw N900EH approximately 250 to 500 feet above the ground, and descending in a right bank of nearly 90 degrees. Within a few seconds, it disappeared behind a row of trees, and all the witnesses concluded that it must have impacted the terrain. None of the witnesses saw the aircraft prior to the time it was already established in the steep bank, and they all reported that the engine did not sound like it was missing, backfiring, or running rough. When the investigative team arrived on the scene, which was located in a soft, damp, level, agricultural field, it was determined that the initial ground contact point, which was co-located with the aircraft's right wing tip, was about eighteen inches wide and four feet long, and only three inches deep at its deepest part (see photo #1). From that point to where the wreckage came to rest was a distance of about 320 feet. Along the entire wreckage track, there were numerous small pieces of metal and composite material, and except for a section of the engine cowling, there were no significant portions of the aircraft structure. The primary structure, to include the fuselage, both wings (which had separated from the fuselage), the empennage, and the engine section, all had come to rest at the very end of the wreckage track. It was noted that although some portion of the aircraft produced ground scars along the vast majority of the wreckage track, almost all of the scars were long and narrow, and all were very shallow (less than two inches deep). It was also noted that there was no clear ground impact damage to the engine, and although all three propeller blades were bent aft at a point about one-third from their root, there was no damage whatsoever to the propeller spinner (see photo #2). The fuselage and empennage were also essentially undamaged from a point just aft of the aft passenger seats. And although the wing carry-through section, which was still attached to the right wing, had torn away from the fuselage, there was no clear indication of ground impact damage to the area around where these two structures are attached to each other. The only two areas that showed clear damage from ground impact were the outboard two feet of the right wing, and a majority of the leading edge of the left wing (which had torn loose from the carry-through spar). A post-accident inspection of the aircraft and engine by an FAA Airworthiness inspector from the Seattle Flight Standards District Office (FSDO), as well as a follow-up inspection of the flight control system by the NTSB IIC, did not reveal any evidence of either an engine malfunction or any pre-impact anomaly in the aircraft's engine, structure or flight control system. An interview with the pilot approximately two and one-half months after the accident revealed that, due to the extent of his injuries, he did not remember anything about the accident sequence, nor did he remember being on the approach to the airport.