Beech 35 N5474D accident near Santa Ynez, California

Probable cause

The pilot’s mismanagement of fuel, which resulted in fuel starvation and a total loss of engine power.

NTSB analysis

As the pilot entered the vicinity to the destination airport, he switched the fuel selector from the right main tank (which was indicating close to empty) to the left main tank (indicating slightly less than half full). As he manipulated the selector handle, the engine experienced a total loss of power. Concerned that the fuel selector was malfunctioning, the pilot placed the selector back on the right tank and attempted to troubleshoot the failure. Despite his efforts, the pilot was unable to retore the engine power and made on off-airport landing into a fence.

A postaccident examination of the engine and fuel system revealed no preimpact mechanical malfunctions or failures that would have precluded normal operation.

The airplane had been modified with a fuel-injected engine. The fuel system was designed for excess fuel at the engine-driven fuel pump to be routed back to the left main wing tank. At normal operating power, about 8-10 gph would be returned to the left tank (as opposed to the carbureted equipped airplane, which would return about 3 gph). The pilot used all the fuel from the right-wing tank and the excess fuel was being ported to the left main tank. The pilot starved the engine for fuel while on the right tank selection and that likely resulted in air entering the fuel system. When the pilot switched to the left main tank, he was either too late or did not allow enough time for the air to purge with the electric fuel pump activated. As a result of this fuel mismanagement, the engine was unable to receive adequate fuel to restart.

Text from the NTSB. Open the NTSB docket for WPR21LA075 for the full record.