Cessna 150A N7032X accident near Santa Monica, California

Probable cause

A failure of the No. 1 piston connecting rod bearing journal due to oil starvation for reasons that could not be determined, which resulted in a complete loss of engine power.

NTSB analysis

During taxi to the runup area, the pilot noticed what he described as a reluctance of the airplane to move, and that its performance seemed sluggish. The pilot subsequently canceled the departure request and taxied to the hangar to troubleshoot the anomaly. While troubleshooting the anomaly, which included adding air to the tires, the pilot performed a magneto check and a carburetor heat check and observed the engine RPM decrease within normal limits. After the second preflight runup, he considered the airplane to be airworthy, taxied onto runway 21, and departed to the southwest. After making a right turn to the northwest along the beach and climbing to about 1,025 ft above ground level (agl), the engine lost power, and the pilot made a 180° left turn to return to the airport.

Unable to make the runway, the pilot made a forced landing to the southeast and attempted to land on the beach. However, the main landing gear contacted the shallow waves, and the airplane nosed over on the shoreline.

Postaccident examination of the airplane’s engine revealed an oil starvation event that occurred at the No. 1 piston connecting rod bearing journal. The No.1 connecting rod separated into 5 identifiable pieces that were recovered from the crankcase. The Nos. 2, 3, and 4 crankshaft connecting rod bearings and journals showed various stages of thermal damage and discoloration. The reason for the oil starvation could not be determined.

While it is likely that the sluggish performance experienced by the pilot during taxi was the beginning of the engine failure, the loss of engine power resulted in a forced landing and subsequent nose over along the shoreline.

Text from the NTSB. Open the NTSB docket for WPR23FA073 for the full record.