During the approach for an attempted forced landing into a clearing near Poulsbo, Wash., the Ercoupe 415C hit trees and then collided with the ground in a nose-down attitude.
The pilot sustained serious injuries during the accident but was able to call 911 on his cell phone. He subsequently died from complications related to his injuries about two weeks later.
Post-accident examination revealed that the engine oil filler cap had not been secured. The oil filler neck and cap were intact and undamaged.
Due to the engine’s design, the engine oil filler cap was located at a low point on the engine. Failure to secure the cap would have resulted in a rapid expulsion of engine oil and a subsequent engine seizure.
An engine examination found damage consistent with oil exhaustion and engine seizure, and the aft section of the engine compartment was coated with oil, which extended out of the cowling and onto the airplane’s belly.
The pilot was operating without a valid medical certificate. The FAA had denied his medical application three years before the accident due to a diagnosis of myelodysplastic syndrome. Although no evidence was found indicating that this medical condition was a factor in the accident, it likely contributed to the pilot’s death because it hindered his recovery from otherwise nonlife-threatening injuries.
The NTSB determined the probable cause as the pilot’s failure to confirm that the engine oil filler cap was secured before flight, which resulted in oil exhaustion and a subsequent total loss of engine power during cruise flight.
NTSB Identification: WPR14LA100
This January 2014 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.