On September 19, 2024, about 0819 Pacific daylight time, a Cessna U206G, N6522Z, was substantially damaged when it was involved in an accident near West Sacramento, California. The pilot sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 other use work flight. According to the pilot, he was enroute from Sacramento Mather Airport (MHR), Sacramento, California, to Watts-Woodland Airport (O41), Woodland, California. Approximately 10 minutes into the flight, at 3,000 ft mean sea level (msl), the engine experienced an abrupt decrease in power and began to shake. The pilot noted that the cylinder no. 4 cylinder’s cylinder head temperature reading was no longer being displayed on the engine data management display, and all other cylinders were “cooling rapidly.” Immediately after the engine power loss, the airplane’s indicated airspeed decreased from 120 kts to 85 kts, and the pilot was unable to maintain altitude. The propeller continued to windmill, but the pilot was unsure how much power the engine was still producing, and he cycled the throttle control from full power to idle, and back to full power. While he cycled the throttle control to idle, and to full power, the shaking decreased, and increased. The pilot declared an emergency to the Northern California Terminal Radar Approach Control facility controller, and identified an open field approximately 2.5 miles northwest of Sacramento Executive Airport (SAC) that he initiated a forced landing to. During the landing roll, the airplane nosed over and came to rest inverted. Postaccident examination of the airplane revealed that both wings, fuselage, vertical stabilizer and rudder sustained substantial damage. The wreckage was recovered to a secure facility for further examination.