NTSB Factual Report

On September 16, 2002, at 0147 central daylight time a Smith Aerostar 601P twin-engine airplane, N90652, was substantially damaged during a forced landing following a dual loss of engine power near Piedmont, Oklahoma. The airplane was registered to Aviation Flight Specialists, LLC., of Wilmington, Delaware, and was being operated by the pilot. The instrument-rated commercial pilot and his one passenger were not injured. Night visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed for the 14 Code of Federal Regulations Part 91 business flight. The cross-country flight originated from Cambridge Municipal Airport, Cambridge, Ohio, at 2147 (2247edt), and was destined for Sundance Airpark Airport, Oklahoma City, Oklahoma.

According to the pilot, who had accumulated a total of 798 hours in the Aerostar, both wing fuel tanks and the fuselage fuel tank were topped prior to departure from Cambridge. The airplane departed and was cleared direct to Oklahoma City. The pilot reported that the 807 nautical mile flight was as expected, with no significant course deviations or unexpected changes in weather conditions, including winds aloft. The pilot reported that he approached Wiley Post Airport and set up for a visual approach to land on runway 17. The airplane was at 700 feet agl turning from the downwind leg to base leg when both engines lost power. During the ensuing forced landing to a field, the airplane collided with a fence and came to rest upright.

An FAA inspector, who examined the airplane, reported that the forward pressure bulkhead on the right side of the airplane was damaged, the six propeller blades (3 on each engine) were bent aft 90 degrees, and the empennage was wrinkled. The left and right wing fuel tanks did not contain any fuel and the fuselage fuel tank contained a "small" amount of fuel. The airplane recovery crew reported that they applied power to the cockpit prior to manipulating the wreckage and observed that the fuel quantity indicators for both wing fuel tanks indicated "zero" and the fuel quantity indicator for the fuselage fuel tank indicated 12, which is in the caution range. The FAA inspector reported that the fuel line fittings near the lower right side of the center fuel tank exhibited "small signs of fuel leaks." The left fuel boost pump, located at the lower left side of the fuselage fuel tank, was the source of the fuel leak. The fuel leak was observed at the fuel pump to bladder tank flange. Fuel stains were found on fuel lines in the flange area and around the aft fuselage area.

A review of the airframe and engine logbooks revealed that the airplane's last annual inspection was completed on July 17, 2002, at a total time of 2,315.0 hours. There were no entries pertaining to the left fuel boost pump, or relating to a fuel leak. At the time of the accident, the airplane had accumulated a total of 2,430.1 hours.

According to the aircraft's pilot's operating manual, the capacity of the fuel system is 173.5 gallons, of which 165.5 are usable. Each wet wing type fuel tank has a capacity of 65 gallons, of which 62 gallons is useable. The fuselage fuel tank has a capacity of 43.5 gallons, of which 41.5 is usable. A caution statement in the manual reads: "The fuselage tank unusable fuel is the only fuel available throughout the complete aircraft maneuvering envelope and, consequently, sufficient fuel must be available in the fuselage tank for takeoff, climb, maneuvering, descent and landing phases of flight." Another caution statement in the manual reads: "The low fuel warning light first illuminates continuously when 12 gallons of fuel remains in the fuselage fuel tank."

NTSB Probable Cause

A fuel leak at the left boost pump to bladder tank flange, which resulted in fuel exhaustion and the subsequent loss of power to both engines.