Flight History
While in cruise flight, the pilot reported that the engine began to run rough. In an attempt to rectify the roughness, the pilot adjusted both the mixture control and the power setting. Following these adjustments, the airplane began to lose airspeed.
Emergency Landing
Faced with decreasing airspeed, the pilot initiated an emergency landing. He flew to the nearest airport but determined there was insufficient altitude or engine power to maneuver the airplane for a landing into the wind. Consequently, the pilot executed a tailwind landing. During the landing roll, the airplane departed the departure end of the runway, entered a drainage ditch, and nosed over.
Post-Accident Examination
A post-accident examination of the engine revealed that the number four cylinder had experienced a pre-ignition/detonation event. Examination of the remaining cylinders showed light combustion deposits.