The pilot was conducting a cross-country flight in an Ercoupe 415 when the engine lost oil pressure. Shortly after, the engine lost power and seized.
The pilot then made a forced landing on a beach near Saint Martin Island, Michigan.
Examination of the engine revealed that the No. 1 connecting rod bearing had failed and that the camshaft had seized and was broken. The camshaft seizure was consistent with a loss of oil pressure due to the No. 1 connecting rod bearing failure.
Probable cause: The failure of a connecting rod bearing, which resulted in a loss of engine power.
NTSB Identification: CEN15LA346
This July 2015 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.