On May 25, 2005, about 1345 central daylight time, a Temco GC-1B, N3875K, piloted by a private pilot, was substantially damaged during takeoff roll when the pilot's seat moved aft causing the pilot to lose of control. The airplane was departing from runway 36 (4,001 feet by 75 feet, asphalt) at Morris Municipal Airport (C09), Morris, Illinois, at the time. The local personal flight was being conducted under 14 CFR Part 91 without a flight plan. Visual meteorological conditions prevailed. The pilot reported no injuries. In his written statement, the pilot reported that he departed Joliet Regional Airport (JOT), Joliet, Illinois, and executed several full stop landings there prior to leaving the traffic pattern for C09. He landed at C09 and taxied back for takeoff. He stated that during the takeoff roll, approximately 55 miles-per-hour (mph), the pilot seat slid "all the way back on [the] seat rail." He reported that he was restrained by the seat belt and shoulder harness and unable to reach the flight or engine controls. The pilot reported the airplane yawed to the left, departing the runway pavement and striking a runway light. He stated the airplane subsequently came back onto the runway before a side load on the main landing gear caused it to collapse. A post-accident inspection of the seat tracks and seat locking components revealed no anomalies. The seat tracks did not appear worn or distorted. The pilot seat locked properly in each position when operated after the accident. Federal Aviation Administration (FAA) records indicated that the original seats and seat tracks were replaced with Cessna 150 components in August 1988. A Major Repair and Alteration statement (FAA Form 337) detailing the alteration was on file with the FAA. FAA Airworthiness Directive (AD) 87-20-03 R2, applicable to Cessna 150 series aircraft, became effective on September 24, 1990. The AD required inspection of the seat tracks and seat locking mechanism components. Worn components and assemblies were required to be replaced. Although the AD addressed issues with the same seat components installed on the accident airplane, because the AD was issued against the Cessna 150 series aircraft it was not applicable to the Temco GC-1B accident aircraft.