On August 24, 2005, at 1330 eastern daylight time, an Ercoupe 415-D, N99746, was substantially damaged during a forced landing, following a total loss of engine power near Sandy Lake, Pennsylvania. The certificated private pilot was seriously injured, and the passenger sustained minor injuries. Visual meteorological conditions prevailed for the flight that departed Rostraver Airport (FWQ), Monongahela, Pennsylvania, about 1230; destined for Port Meadville Airport (GKJ), Meadville, Pennsylvania. No flight plan was filed for the personal flight conducted under 14 CFR Part 91. Prior to departing Monongahela, the pilot added 6.99 gallons of 100LL aviation gasoline to the airplane. Sandy Lake was approximately 70 miles north of Monongahela, and Port Meadville was about 15 miles north of Sandy Lake. A witness, near the accident site, observed the accident airplane and heard engine noise. She then heard no engine noise, and observed the airplane glide into trees. The airplane subsequently came to rest in a 60-foot-tall tree. The passenger reported to emergency personnel that, "the fuel pump quit." The airplane was manufactured in 1946. Examination of the wreckage by a Federal Aviation Administration (FAA) inspector revealed that the airplane was equipped with a 6-gallon fuselage fuel tank (also called a header tank), a 9-gallon right wing fuel tank, and a 9-gallon left wing fuel tank. The right wing fuel tank was compromised, and fuel stains were present on the right wing. In addition, emergency personnel observed fuel leaking from the right wing when they responded to the scene. The left wing fuel tank was also compromised, and leaking fuel. The fuel cap was absent from the fuselage fuel tank. The FAA inspector could not confirm if the cap was ejected during the impact, and he did not recover the fuel cap. On October 18, 2005, a re-examination of the wreckage was conducted under the supervision of a Safety Board investigator. Some residual fuel was observed in the fuselage fuel tank and gascolator. A sample of fuel was recovered from the gascolator. The fuel was bright, clear, and consistent and color and odor with 100LL aviation gasoline. When water-finding paste was inserted in the fuel sample, the paste remained its original color, indicating that no water was present in the sample. Some sediment was noted at the bottom of the sample. The engine driven fuel pump was removed from the engine for examination. When the pump was actuated by hand, it was noted that there was no movement or continuity to its mechanical linkage that connected into the engine. The propeller had bent rearward during the impact sequence. The bent propeller was removed and reinstalled inverted, so that it would not strike the airframe. The inoperative pump was re-attached to the engine to prevent oil leakage, and 5 gallons of gasoline was added to the fuselage tank. The fuel valve was positioned to the open position, and the engine was primed twice. When the starter was engaged, the engine started on the first attempt without hesitation, and ran continuously at idle power for 15 - 30 seconds. The engine was then shut down using the magneto key switch. The process was repeated two additional times with the engine running continuously at idle and partial power. Due to vibration, the engine was not run to maximum power. Review of a flight manual for an Ercoupe 415-D revealed that a fuel gauge was incorporated into the fuselage fuel tank cap. Fuel flowed from the wing tanks, via the engine driven fuel pump, to the fuselage tank. Once in the fuselage tank, fuel was gravity fed into the engine. Further review of the manual revealed, "In case of fuel pump failure, the engine will continue to function until the six gallon fuselage tank is drained." The aircraft logbooks were not recovered, and the date of the last maintenance inspection was unknown. The most recent entry in the pilot's logbook was dated June 4, 2005. According to the logbook, the pilot had accumulated a total flight experience of approximately 835 hours; of which, about 20 hours were in the accident airplane.