Cessna 172RG N751DW accident near Chandeleur Island, Louisiana

Probable cause

A fatigue failure of the engine oil pressure line, which resulted in the loss of engine oil during the flight and subsequent damage to the nose landing gear support structure during the precautionary landing.

NTSB analysis

The pilot reported that about an hour and twenty minutes into the flight he smelled smoke and noticed that the oil pressure was decreasing. He diverted for a precautionary landing. By that time, the oil pressure had dropped to zero and the cabin was filling with smoke. He landed on a beach, and the nose landing gear dug into the sand and collapsed. The landing gear well structure sustained substantial damage during the precautionary landing.

A postaccident examination determined that the oil pressure line from the engine to the firewall fitting had fractured due to fatigue. The line was bent about 360° near mid-span, and the line was fractured within the bent segment.

Airplane maintenance records revealed that the engine was overhauled and reinstalled on the airframe about a month before the accident. The mechanic noted that the oil line was inspected and reinstalled after the overhaul. The airplane had accumulated 119 hours since the engine overhaul.

Text from the NTSB. Open the NTSB docket for CEN24LA211 for the full record.