On April 14, 1997, approximately 1415 Pacific daylight time, a Piper PA-24-260, N8645P, was substantially damaged in a forced landing attempt following a loss of engine power east of Sequim, Washington. The private pilot-in-command, who owned the aircraft, received minor injuries. A second pilot, who was a certificated flight instructor, was seriously injured. No flight plan had been filed for the 14 CFR 91 flight, which was bound for Port Angeles, Washington from Bremerton, Washington. The flight originated at Mulino, Oregon (approximately 22 nautical miles south of Portland), with an intermediate stop at Bremerton. The aircraft's fuel system consists of a main (28 gallons usable) and auxiliary (15 gallons usable) tank in each wing, for a total usable fuel capacity of 86 gallons. The pilot reported to an FAA inspector assigned to the accident that he took off from Mulino with 13 to 14 gallons in each wing, and flew from Mulino to Bremerton (a straight-line distance of approximately 137 nautical miles) at approximately 1,500 feet altitude on the left tanks. According to the PA-24-260 owner's manual, at an altitude of 2,000 feet and 65% power the aircraft cruises at a true airspeed of approximately 166 MPH (144 knots) with a fuel burn rate of approximately 12.6 to 14.4 gallons per hour. Calculation of estimated fuel remaining in the left wing tanks upon arrival at Bremerton, based on the above parameters of distance, true airspeed, and burn rate with zero wind, yielded approximately 1.1 to 3.6 gallons (5 to 17 minutes of fuel remaining in the left wing tanks at the above burn rates.) The pilot serviced the aircraft's right wing tanks with 28.3 gallons of fuel at Bremerton. Based on this fuel servicing, the reported fuel of 13 to 14 gallons in the right tank on departure from Mulino, and flight from Mulino to Bremerton on left tanks, the right wing tanks upon departure from Bremerton were approximately full. The pilot reported that he took off from Bremerton with a left tank selected, and that approximately 10 minutes later, after switching to the right tank, the engine "missed" and "sputtered", running "off and on for several minutes." The pilot stated that he activated the aircraft's electric fuel pump, and that he tried all tanks but the engine subsequently failed. The pilot stated that he then relinquished control of the aircraft to the instructor, who attempted the forced landing. Information from the FAA indicated that the forced landing attempt was onto a road, but the aircraft contacted trees prior to touchdown. The accident site was approximately 35 nautical miles from Bremerton and 23 nautical miles from Port Angeles. On-site examination revealed that the accident aircraft's left wing tanks were empty and its right wing tanks were full, although the aircraft's fuel selector valve was positioned to "right main." Fuel samples taken from the accident aircraft and from the fuel tanks at Bremerton revealed no visual evidence of impurities or contamination. Review of fueling system inspection records furnished by the Port of Bremerton indicated that required checks of the fueling system at the airport had been performed, and that test samples taken of the airport fuel supply on the date of the accident had been clear. FAA investigators reported that preliminary on-site examination revealed no evidence of mechanical discrepancies with the engine, and that they were able to rotate the engine by hand. A post-accident test run of the aircraft's Lycoming IO-540-D4A5 engine was conducted at the facilities of Rotor-Technics, Renton, Washington, on April 25, 1997. Investigators from the NTSB, FAA, The New Piper Aircraft, and Textron Lycoming participated in this examination. During this examination, a fuel supply containing fuel drained from the accident aircraft's right wing tanks was connected to the right main tank feed line (the selected tank at the accident site.) In this configuration, investigators were able to successfully start and run the accident aircraft's engine. The engine was responsive to throttle changes. The aircraft's electric fuel pump activated properly when switched on. Investigators were also able to verify proper flow continuity from each of the four fuel tank feed lines (left aux, left main, right main, and right aux) through the fuel selector valve to the engine. The pilot stated on his NTSB accident report that his last FAA medical examination was in April 1995, but the last medical examination on file with the FAA was in 1981. The pilot did not furnish a copy of his FAA medical certificate with his report, as he had been requested by the NTSB investigator-in-charge (IIC) to do.