On February 27, 2000, an Ercoupe (eng & Research Corp.) 415-C (registration N99590) was involved in an aviation accident near San Bernardino, CA. Investigators recorded the probable cause as: The failure of the number 1 engine cylinder exhaust valve at the valve neck, which resulted in total loss of engine power. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A vintage airplane experienced total power loss during cruise flight due to a failed exhaust valve, resulting in an off-airport landing and fence collision.
The aircraft was operating in cruise flight when the engine began to run roughly. Shortly thereafter, the engine lost power totally. The pilot executed an off-airport landing and collided with a fence.
A postaccident examination of the engine revealed that the number 1 engine cylinder exhaust valve had failed at the valve neck.
The failure of the number 1 engine cylinder exhaust valve at the valve neck, which resulted in total loss of engine power.