Piper PA-32-300 N841AD accident near Corona, California

Probable cause

The airplane’s partial loss of engine power during the landing for reasons that could not be determined based on the available evidence, which resulted in an off airport landing and subsequent fire.

NTSB analysis

The pilot reported that the engine lost partial power when he adjusted the engine power while entering the downwind leg of the traffic pattern. The engine did not respond, so he cycled the throttle several times with no change. Unable to maintain altitude, he initiated a forced landing onto a freeway, during which the airplane impacted a freeway barrier and a postaccident fire ensued that resulted in substantial damage. The pilot further reported that he did not believe he turned on the auxiliary fuel pump switch before the accident.

Examination of the airframe and engine revealed that the fuel supply line from the engine driven fuel pump to the fuel servo had a torsional twist near the engine driven fuel pump outlet port. The engine-driven fuel pump was removed and exhibited signatures consistent with a preexisting fuel leak at the case split, along with corrosion to the input drive seal area. The pump was tested utilizing a test bench, the fuel pump output pressure was found to be within manufacturer limits despite the preexisting leak and likely did not contribute to a loss of engine power. It could not be determined how much the kinked fuel line restricted the fuel flow to the fuel servo. Downloaded engine monitoring data showed that fuel flow was within the manufacturers specified limits, thus it’s likely that the twisted fuel line did not contribute to the loss of engine power. The loss of engine power could not be determined due to the available evidence.

Text from the NTSB. Open the NTSB docket for WPR22LA296 for the full record.