On January 10, 2004, about 1425 eastern standard time, a Piper PA-24-260, N1XF, was substantially damaged during a forced landing, following a total loss of engine power while on approach to Bradford Regional Airport (BFD), Bradford, Pennsylvania. The two certificated flight instructors and a passenger were not injured. Visual meteorological conditions prevailed for the flight that departed Syracuse Hancock International Airport (SYR), Syracuse, New York. An instrument flight rules flight plan was filed for the personal flight conducted under 14 CFR Part 91. The pilot-in-command (PIC) in the left seat stated that he planned to practice some instrument approaches at SYR, with the pilot in the right seat acting as a safety pilot. Prior to departing BFD, the main fuel tanks were "topped off." The PIC further stated that the airplane had a supplemental type certificate for two fuel selectors; one for each wing. Each fuel selector could be positioned to "Main," "Aux," "Tip," or "Off." The flight departed BFD about 1200, with both fuel selectors positioned to "Main," and flew uneventfully to the SYR area. The PIC completed several instrument approaches, and began a return to BFD about 1330. Approaching the BFD area, the flight was cleared to descend from 6,000 feet to 4,000 feet, and the PIC intended on flying the VOR RWY 14 approach. During that time, while both fuel selectors remained positioned to "Main," the engine "hiccupped." About 6-7 miles northeast of the BFD VOR, while descending, the engine experienced several minor power surges, and then lost all power. The PIC established a proper glide speed, and the safety pilot initially suggested a right base leg for runway 32. However, the PIC chose runway 23 because it was a straight-in approach from his position. During the glide, the PIC completed the emergency checklist items, which included verification that the electric fuel pump was on, and cycling the fuel selectors through all tanks. The PIC was unable to restart the engine, and continued the glide toward runway 23. The PIC maintained glide speed, and initially thought he would reach the runway, but the airplane impacted small trees about 2,500 to 3,000 feet prior to the runway. The PIC added that there were no suitable fields near the airport. Examination of the engine by a Federal Aviation Administration (FAA) inspector did not reveal any pre-impact mechanical malfunctions. The inspector observed fuel in all fuel tanks, and fuel was present from the selector valve, to the fuel servo, to the flow divider. When power was applied to the electric fuel pump, it operated continuously. The inspector noted that the right fuel selector handle was difficult to move, with some debris lodged in it. He also observed that the throttle idle adjustment bushing was missing. However, the inspector could not determine if the bushing separated during flight, or during the forced landing. Subsequently, a flow test of the fuel servo and flow divider was conducted at the manufacturer's facility, under the supervision of another FAA inspector. Except for the number six port on the flow divider, which flowed 8 percent lower than the minimum allowed value, the units tested within limits.