On November 18, 2001, an Ercoupe (eng & Research Corp.) 415-C (registration N99236) operated by William K. Johnson was involved in an aviation accident near Southern Pines, NC. Investigators recorded the probable cause as: The dislodging of the front crankshaft oil seal for undetermined reasons resulting in loss of engine oil, loss of engine power, and collision with a tree and then the ground during a forced landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot lost engine oil pressure and temperature before an emergency landing on a golf course after the engine lost power. Postcrash inspection found no oil in the tank and a dislodged front crankshaft seal.
Accident Sequence
The pilot reported adding 1.2 quarts of oil to fill the engine oil tank before departing on a short test flight over his home airport. After the test flight, no evidence of engine oil leakage was observed. At 1250, he departed Parkton for Southern Pines. Approximately 10 miles from Southern Pines Airport, the engine began to run rough. The pilot continued toward the airport as the engine oil temperature rose and oil pressure dropped. The engine then lost power, preventing the pilot from reaching the airport. During a forced landing on a golf course, the left wing struck a tree, and the airplane descended and impacted the ground.
Postcrash Examination
A Federal Aviation Administration (FAA) inspector examined the airplane after the accident. The propeller showed damage consistent with very slow rotational speed at ground impact. Oil spray was noted on the engine cowling and the bottom side of the engine. The engine oil tank contained no oil.
Engine Examination
The engine was examined by an FAA inspector at an engine overhaul facility. The front crankshaft seal was found dislodged, which allowed oil to escape from the engine at a substantial rate when the engine oil system was pressurized. No obstructions were found in the engine case vent system that would have caused over-pressurization of the engine case. The reason for the dislodged crankshaft seal was not determined.