Flight Details
The airplane departed on a cross-country flight and landed after 54 minutes. Without refueling, it departed for the return trip. 1 hour and 2 minutes into the return flight, the pilot reported a rough running engine and a loss of power. The airplane subsequently impacted a four-lane interstate highway.
Fuel Consumption and Preflight
On a standard day, the airplane would consume 9.1 gallons per hour at 63 percent power and 6,500 feet, or 12.3 gallons per hour at 75 percent power. Witnesses reported that the day before the accident, the aircraft had 7.5 gallons in the left tank and 15 gallons in the right tank. The airplane was then flown for 1.3 hours. After that flight, the airplane was not serviced until just before the accident flight, when 13.2 gallons of fuel was added. The pilot's operating handbook requires the pilot to visually check the fuel quantity for both tanks during the preflight inspection.
Wreckage Examination
Examination of the wreckage revealed no preimpact failures or malfunctions. Additionally, examination of the engine revealed evidence consistent with fuel starvation.