Casualties unknown

Engine failure forces river delta landing after connecting rod fracture (N75941)

Larsen Bay, AK, US

On June 25, 1984, a Cessna 207A (registration N75941) was involved in an aviation accident near Larsen Bay, AK. Investigators recorded the probable cause as: Mechanical failure of the number two connecting rod (part number 633403), which punctured the engine crankcase and caused oil pressure loss. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

A twin-engine aircraft experienced an in-flight engine shutdown due to mechanical failure, resulting in a forced landing on a river delta where the nose gear collapsed.

What happened

Approximately twelve minutes after takeoff, while the aircraft was climbing through an altitude of 2300 feet mean sea level, the number two engine began to shake violently. Oil subsequently covered the windshield as oil pressure was lost. The pilot then executed a forced landing in an area characterized by tall grass on a river delta. During the touchdown, the nose gear collapsed and the propeller sustained damage.

The investigation

A post-accident examination of the aircraft revealed that the number two connecting rod, part number 633403, had failed. This mechanical failure punctured a hole in the engine crankcase, leading to the loss of oil pressure and subsequent engine shutdown.

Findings

The investigation identified mechanical failure of the number two connecting rod as the primary factor. The fracture caused a breach in the crankcase, resulting in total oil loss and the inability to maintain engine operation.

Probable cause

Mechanical failure of the number two connecting rod (part number 633403), which punctured the engine crankcase and caused oil pressure loss.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X39776. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.