Accident Overview
Approximately two hours after departing on an aerial pipeline patrol flight, the pilot activated the fuel transfer pump to move fuel from the auxiliary baggage fuel tank to the airplane's right wing fuel tank. The pilot noted that this was his standard routine and estimated the transfer would take about two hours.
Engine Sputter and Forced Landing
Almost four hours after departure, the engine "sputtered." The pilot rocked the wings and observed that the fuel transfer pump appeared to be off. He then reactivated the pump, and the fuel transfer light illuminated. However, the airplane was too low to wait for fuel to reach the wing tank and then the engine. The pilot decided to perform a forced landing to a field.
Collision and Damage
During the forced landing, the airplane collided with several tree branches before impacting the ground and flipping onto its back. The accident resulted in substantial damage to the right wing, aft fuselage, and top of the vertical stabilizer.
Pilot's Observations
The pilot reported that after initially starting the fuel transfer, the transfer pump apparently turned off without his notice. He believed that enhancing the cockpit indication of pump status could prevent such occurrences.
Recommendations
In the NTSB pilot/operator aircraft accident/incident report form, the pilot recommended moving the auxiliary fuel gauge and indicator light to the instrument panel, or installing a fuel flow meter on the instrument panel, to aid in noticing whether the fuel transfer pump is on or fuel is actually transferring from the auxiliary tank.