On August 9, 1999, about 0850 eastern daylight time, a Cessna 150G, N3187X, registered to Advanced Flight Training, Inc., collided with terrain near Greeneville, Tennessee, while on a Title 14 CFR Part 91 personal flight. Instrument meteorological conditions prevailed at the time and a visual flight rules flight plan was filed. The aircraft received substantial damage and the private-rated pilot received minor injuries. The flight originated from Tri-Cities Regional Airport, Blountville, Tennessee, the same day, about 0815. The pilot stated that while en route from Blountville, to Collegedale, Tennessee, at 3,000 feet, he encountered weather and decided to return to Blountville. As he made a left turn back towards Blountville, he entered a cloud. He became disoriented and lost control of the aircraft. He began flying the aircraft by reference to the flight instruments and regained control. He climbed to 3,500 feet and made a left turn back toward Blountville, where he believed the weather was better. While in cruise flight, in the clouds, flying to the north, he encountered rising terrain and the aircraft collided with trees. The aircraft crashed through the trees and came to rest inverted. He exited the aircraft and called for assistance on a portable telephone. He reported he had no mechanical difficulties with the aircraft.