Accident Overview
A student pilot and a flight instructor were involved in an accident during a night cross-country flight when the airplane experienced a loss of engine power. The aircraft subsequently collided with an automobile during a forced landing on a freeway.
Flight Details
The student pilot had recently purchased the airplane and was returning it to her home airport with the flight instructor. During a cruise descent, the engine began to lose power. The student pilot activated the electric fuel pump, but it had no effect. She then transferred control of the airplane to the instructor and began operating the hand pump. The engine speed increased while she pumped but decreased when she stopped. The instructor instructed her to switch through all fuel tanks, but this did not resolve the issue. The engine produced power only while the hand pump was operated, and even then, it ran at a low RPM.
Forced Landing and Collision
As the airplane lost altitude and descended to between 1,000 and 2,000 feet above a freeway, the student pilot could no longer continue pumping due to physical fatigue. They decided to execute a forced landing on the freeway. Turning onto final approach at about 300 to 400 feet, they flashed the landing light at 10 to 15 feet above ground level to warn drivers. Within 2 to 3 feet of landing, the student pilot noticed a car to the left of the airplane. The left wing struck the lower part of the car, causing the airplane to cartwheel and come to rest inverted.
Post-Accident Observations
After exiting the airplane, the student pilot observed fuel leaking from both wings. First responders reported an 8-foot-diameter puddle of fuel beneath the wreckage.
Investigation Findings
Examination of the engine revealed no preimpact anomalies that would have precluded normal operation. The engine-driven fuel pump functioned when tested with an electric drill. However, the electric fuel boost pump did not rotate. Inspection of the pump found that the roll pin inside had sheared into two pieces, with one piece lodged in the vanes and preventing rotation. The technician who disassembled the pump noted that such damage typically occurs when the pump has been run dry.
Fuel System Considerations
The student pilot stated that at the last fuel stop, she had used the electric fuel pump as a primer, during which the fuel pressure rose to 9 psi. She did not use the pump again until the accident. The underlying reason for the apparent failure of the engine-driven pump and other fuel system components to deliver sufficient fuel to the carburetor could not be determined.