Accident Overview
The airplane made an emergency landing and subsequently collided with a berm located in a construction area. The incident occurred after a flight of approximately 1.5 hours.
Sequence of Events
During the descent, the pilot experienced a surging left engine and observed the left boost pump warning light flashing. The left engine continued to surge, and the warning light remained fully illuminated. The pilot chose not to feather the left propeller. He engaged both emergency fuel boost pumps and advanced the throttles and propellers for both engines. Despite these actions, the engines did not produce enough power to sustain flight.
Air traffic control identified two nearby airports: one 6 miles away and another 2 miles away. At an altitude of 4,000 feet above ground level, the pilot determined that he would not be able to reach either airport.
Manufacturer's Procedures
According to the manufacturer's published emergency procedures, once an inoperative engine has been identified and an unsuccessful engine restart attempt is made, the pilot should feather the propeller.
Post-Accident Findings
During recovery, personnel noted that the inboard fuel tanks were full of fuel. Both outboard fuel tanks were empty; however, fuel was found on the ground near one of the outboard fuel tanks. The operator stated that pilots are encouraged to burn out the fuel in the outboard tanks monthly during visual flight rules conditions.
A functional check of the continuous duty fuel boost pumps and emergency fuel boost pumps revealed no discrepancies. According to the pilot's operating handbook (POH), the continuous duty fuel boost pump warning lights illuminate when system pressure drops below 3 PSI or when the boost pumps have failed. Engaging the emergency fuel boost pumps provides steady fuel pressure.
The POH also describes that the fuel system has right and left fuel warning lights. These fuel flow warning lights illuminate to warn of an impending fuel flow interruption and are located beneath the fuel boost pump warning lights. If the fuel level near the tank outlet drops to a point where a fuel flow interruption and power loss could occur, a sensing probe illuminates the corresponding warning light.
Inspection of the fuel system confirmed that the system was intact and operated normally. The cross feed valves were operated, and fuel was observed to flow to each engine from the opposite wing fuel tank. No mechanical anomalies were noted.