Event
The airplane was damaged during a forced landing in a muddy field following a loss of engine power. The pilot reported that while in cruise flight at 23,000 feet mean sea level, he heard a "medium loud pop" about one hour into the flight and noted an immediate drop in manifold pressure to approximately 15 inches. The pilot stated he believed the turbocharger had failed and expected engine power to return when descending below 10,000 feet; however, engine power never recovered. He elected to execute a forced landing to a muddy pasture.
Examination
Two safety inspectors from the Federal Aviation Administration (FAA) performed an on-scene examination of the airplane and engine. The pilot landed in a muddy pasture, and the airplane sustained substantial damage to the fuselage, engine firewall, and landing gear. Examination of the engine, accessories, and fuel system revealed no mechanical deficiencies. When the airplane was recovered, approximately 90 gallons of blue-colored aviation fuel was drained from both wing tanks and their respective collector/sump tanks, which are located at the root of each wing. Approximately one quart of water was drained from both the left and right wing collector/sump tanks, each with a capacity of one U.S. gallon.
Engine Test
The engine was test-run on the airframe using the airplane's existing fuel system. Due to cool outside air temperature, the engine required priming to start. Once started, it was operated through various power settings and ran continuously without interruption. The magnetos functioned normally, and all engine gauge readings were normal. No mechanical deficiencies were noted that could have contributed to the loss of power.
Pilot Statement
The pilot stated that he conducted a preflight inspection of the airplane, which included draining both collector/sump tanks, and that no water was detected in the fuel at that time.