On February 7, 1996, at 0345 eastern standard time a PA-32-RT-300, N2200J, made a forced landing at Tri-City Regional Airport, Blountville, Tennessee, after a portion of the engine cowling departed the airplane and struck the right horizontal stabilizer. The dual training flight was operated under the provisions of Title 14 CFR Part 91, and instrument flight rules. An instrument flight plan was active and visual meteorological conditions prevailed. The airplane was enroute to Charlottesville, Virginia, and was approximately 35 miles southwest of Holston Mountain VOR at the time of the accident. The instrument rated certified flight instructor and his student were not injured, and the airplane was substantially damaged. The instrument instruction flight had departed Birmingham, Alabama about 0115 the same day. Both pilots agreed that during the preflight inspection the engine cowling was not opened, the cowling looked normal, and no fasteners were missing. According to the flight instructor, the airplane was above a cloud layer in visual meteorological conditions, at 9000 feet when approximately 1/2 of the engine cowling departed the airplane. Full up elevator was needed to maintain level flight. The flight instructor noted that the elevator trim was reacting opposite it's normal direction. They diverted to Tri-City Regional Airport. The morning following the accident the flight instructor found pieces of the engine cowling lying next to the airplane. The airplane maintenance records revealed that the airplane passed a 100 hour inspection on October 6, 1995, and had accumulated 51 hours since this inspection. A discrepancy report was filed on October 26, 1995 for a drip of oil on the head (left cowling). This discrepancy was resolved on October 27, 1995. The FAA Air Safety Representative that examined the airplane stated that the cowling had become lodged in the elevator and dislodged upon touchdown. All of the pieces of the cowling were recovered except for the left cowl pin. He stated that both of the left cowl latches were attached, and in the latched position. The FAA Coordinator stated that there are no maintenance or difficulty reports on this airplane's cowling, and that the cowl pin did not fail. The manufacturer had no record of a similar previous failure in the same make and model airplane.