On July 17, 2004, at approximately 1900 mountain daylight time, a Mooney M20C, N6773U, operated by EPM AV Corp., was substantially damaged following a loss of engine power when it impacted terrain during a forced landing to a sand bar near the Escalante River, approximately 15 nautical miles east of Escalante, Utah. The private pilot and passenger were not injured. Visual meteorological conditions prevailed at the time of the accident. The local personal flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The flight originated at Escalante, at approximately 1835. The pilot stated that approximately 25 minutes into the flight, the engine began to run rough and shake "violently." A few moments later, blue smoke came out of the engine cowling and filled the cabin. The pilot shut down the engine, and attempted a forced landing on an exposed sand bar adjacent to the Escalante River. When the airplane impacted the sand bar, the nose landing gear and both main landing gear assemblies collapsed, substantially damaging the airplane's firewall and both wings. According to the pilot, an engine examination revealed that the brass quick-drain fitting that was installed in the engine's oil pan, became unscrewed and fell out. The quick-drain fitting was not secured with safety wire.