On June 22, 1996, a Cessna 170A (registration N9230A) was involved in an aviation accident near Southside, AL. Investigators recorded the probable cause as: Rupture of the oil line from the engine to the oil cooler, resulting in loss of engine oil and subsequent engine seizure. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot reported a drop in oil pressure and a loud noise, followed by total engine power loss. The forced landing with a tailwind resulted in a long touchdown, runway overrun, and aircraft nose-over. Investigation found a ruptured oil line caused engine oil loss and seizure.
Incident Summary
During cruise flight at an altitude of 2,000 feet, the pilot observed a sudden drop in oil pressure accompanied by a sound reminiscent of a connecting rod coming loose. Immediately thereafter, the engine experienced a total loss of power. The pilot executed a forced landing to a private airstrip. The approach was steep and high to clear a nearby house, and the aircraft landed with a tailwind. The airplane touched down beyond the intended landing point, overran the end of the runway, and nosed over.
Mechanical Examination
Post-accident examination of the aircraft revealed that the oil line connecting the engine to the oil cooler had ruptured. This failure led to a complete loss of engine oil, which in turn caused the engine to seize. The ruptured oil line was identified as the direct cause of the engine power loss.
Probable cause
Rupture of the oil line from the engine to the oil cooler, resulting in loss of engine oil and subsequent engine seizure.