19991210044399A

(-23) PIC reported that he departed flg for his destination phx. After he had entered phx class b airspace at about 4000 MSL he experienced a power surge in the left engine and continued nonstop in spite of his attempt to correct the problem. He declared a mayday and made an emergency gear up landing in construction area west of Scottsdale airport. (.4)the airplane collided with a berm in a construction area after making an emergency landing. Following a flight of about 1.5 hours and after starting a descent, the pilot felt the left engine surge, and saw the left boost pump warning light flashing. The left engine continued to surge and the boost pump light remained fully illuminated. He chose not to feather the left propeller. He engaged both emergency fuel boost pumps and advanced the throttles and propellers for both engines. In this configuration the engines did not produce enough power to sustain flight. ATC identified two nearby airports for the pilot; one airport was 6 miles away and the other was 2 miles away. At 4,000 feet AGL, the pilot felt he would not make either airport. According to the manufacturer's published emergency procedures, once an ino perative engine has been identified and an unsuccessful engine restart attempt is made, the pilot should feather the propeller. During the recovery, personnel noted that the inboard fuel tanks were full of fuel. Both outboard tanks were empty; however, fuel was found on the ground by one of the outboard fuel tanks. According to the operator, once a month the pilot's are encouraged to burn out the fuel in the outboard fuel tanks in VFR conditions. Following the accident, a functional check was conducted of the continuous duty fuel boost pumps and emergency fuel boost pumps. No discrepancies were noted. According to the pilot's operating handbook (POH), the continuous duty fuel boost pump warning lights will illuminate when pressure to the system drops below 3 PSI or the boost pumps have failed. Engagement of the emergency fuel boost pumps provides steady fuel pressure. The POH further reports that the fuel system has right and left fuel warning lights. The fuel flow warning lights illuminate to warn the pilot of an impending fuel flow interruption. These lights are located underneath 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 will illuminate its corresponding warning light. An inspection of the fuel system revealed 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 side wing fuel tank. No mechanical anomalies were noted.