On September 27, 1998, at 0925 mountain daylight time, a Cessna T-50, N6HS, registered to and operated by the pilot as a 14 CFR Part 91 personal flight, experienced a loss of engine power and subsequent forced landing shortly after takeoff from the Missoula International Airport, Missoula, Montana. During the landing roll in a field, the airplane collided with a fence. Visual meteorological conditions prevailed at the time and a visual flight rules flight plan was filed. The airplane was substantially damaged and the airline transport pilot and his passenger were not injured. The flight was en route to Coeur d'Alene, Idaho. In a written statement, the pilot reported that shortly after takeoff, the right engine lost power. The pilot stated that he was unable to maintain altitude and continued straight ahead, and landed the airplane in a pasture. During the landing roll, the airplane collided with a fence before coming to rest. The pilot stated that after the accident, fuel was observed running from the right engine drain valve. Witnesses reported that fuel was observed flowing from the right engine lower nacelle as the pilot was starting the engines in preparation for taxi and departure. One witness approached the aircraft and told the pilot of this situation. The pilot disregarded this information and proceeded to start the right engine and taxi to the runway. After the accident, fire department personnel observed fuel flowing from the right engine. One fireman reported that he opened the access panel and found that the gascolator quick drain was locked in the open position. The fireman turned the mechanism 90 degrees and the drain sprang shut. The fuel flow then stopped. After the aircraft was moved to the airport, a Federal Aviation Administration Inspector from the Helena, Montana, Flight Standards District Office inspected the gascolator quick drain. The inspector found that the mechanism operated with no mechanical failures or malfunctions noted.