On August 7, 2009, about 1030 central daylight time, an amateur-built CH 701 experimental light sport aircraft, N75644, was substantially damaged during a forced landing near Murfreesboro, Tennessee. The certificated private pilot and the pilot-rated passenger were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight, which departed from Murfreesboro Municipal Airport (MBT), Murfreesboro, Tennessee, and was destined for Smyrna Airport (MQY), Smyrna, Tennessee. The flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to the pilot, he and his passenger had previously flown from his home base at MQY to MBT without incident. Later in the day, the pilot performed a preflight inspection and engine run-up for the return flight to MQY. About 15 minutes after departing MBT, and while flying approximately 1,000 feet above ground level, the engine "stopped." The pilot immediately established the airplane in a glide, and began looking for a suitable landing site. The pilot asked the passenger to attempt an engine restart, but the passenger was not successful. The pilot subsequently performed a forced landing to a pasture, during which the nose landing gear buckled, resulting in substantial damage to the airframe. An examination of the engine by a Federal Aviation Administration inspector revealed that the alternator drive gear had sheared off, and had become lodged in the accessory drive gears, jamming them. Additionally, the alternator drive gear retaining nut, which was found in the engine oil sump, did not have a cotter pin locking device installed. According to the FAA records, the experimental amateur-built airplane was certificated in 2008. The pilot stated that the airplane had accumulated 43 total hours of operation since that time. The airplane’s most recent condition inspection was completed on August 1, 2009, and the airplane had accumulated 3 hours of operation since that time. At the time of the accident, the engine had accumulated 46 total hours, and 43 hours since its last overhaul. According to the pilot, he held a private pilot certificate with a rating for airplane single-engine land. He reported 550 total hours of flight experience, 6 hours of which were in the accident airplane make and model. The 1153 recorded weather observation at MQY, located 11 nautical miles northwest of the accident site, included variable winds from 110 degrees at 5 knots, 6 statute miles visibility in haze, clear skies, temperature 31 degrees C, dew point 21 degrees C, and an altimeter setting of 30.18 inches of mercury.