On December 7, 1993, a Wonder VAN'S ACFT RV-6 (registration N443MW) was involved in an aviation accident near Ridgeland, SC. Investigators recorded the probable cause as: IMPROPER INSTALLATION OF THE MAGNETOS BY MAINTENANCE PERSONNEL, WHICH ALLOWED THE RIGHT MAGNETO TO COME LOOSE, OIL TO ESCAPE FROM THE ENGINE, AND SUBSEQUENT OIL STARVATION. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot performed an emergency landing in a cotton field after the engine seized due to a magneto separation. During the landing roll, soft dirt caused the airplane to nose over.
Incident Overview
The pilot of a single-engine airplane experienced engine trouble during descent. A slight engine vibration was noted before descent began. During the descent, the electronic tachometer for the right magneto indicated zero, and blue smoke entered the cockpit. Oil subsequently covered portions of the windscreen, and the engine seized. The pilot executed an emergency landing in a cotton field approximately seven miles west of the intended destination airport.
Landing and Post-Accident Examination
During the landing roll, the airplane encountered an area of soft dirt and nosed over. Post-accident examination of the engine revealed that the right magneto had separated from the crankcase, creating a large hole through which oil could escape. The left magneto was also found to be in the early stages of separation from the engine. The magnetos had been installed 16 hours before the accident by a certified repair station.