Cessna R182 N7392X accident near Hesperia, California

Probable cause

The separation of the end baffle cone inside the muffler, which blocked airflow through the engine after takeoff and resulted in a loss of engine power and an off-airport landing into obstacles.

NTSB analysis

The airplane's engine stopped making sufficient power to maintain a climb, so the pilot decided to turn back toward the airport. However, after he flew into a valley, he realized that the airplane would not make it back to the airport. After seeing power lines along the airplane's flightpath, he turned the airplane toward an open field. The airplane subsequently hit the ground hard and then hit a tree, which separated the right wing from the airframe. During the postaccident engine examination, the muffler was disassembled. One internal baffle cone was found separated from the end plate and was blocking the opening of the muffler. Upon shaking the muffler, the baffle cone was free to move around within the muffler assembly. The other baffle cone had a hole eroded in its center. Internal engine failures can cause partial or complete engine power loss by restricting the flow of the exhaust gases. If pieces of the internal baffling break loose and partially or totally block the flow of exhaust gases, an engine failure can occur. It is likely the exhaust gas was partially or totally blocked by the separated baffle cone during the flight, which resulted in a loss of engine power.

Text from the NTSB. Open the NTSB docket for WPR11LA311 for the full record.