Accident Summary
The pilot planned a 4-hour flight using a fuel consumption rate of 8 gallons per hour, carrying enough fuel for 5 hours. Midway, the flight descended from the planned 8,000 feet to 6,000 feet at the pilot's request. Slight vectoring occurred for weather avoidance. Near the destination, the pilot noted the fuel gauges indicated empty but elected to continue after seeing the city lights. While being vectored onto final approach for a localizer approach, the engine experienced a total loss of power due to fuel exhaustion. During the forced landing to a highway, the airplane collided with unmarked power lines and a vehicle. The right rear seat passenger was ejected during the impact sequence.
Investigation Findings
Ground examination revealed a 2-foot by 2-foot fuel stain under the left wing fuel tank, and 8 ounces of fuel were drained from the right wing tank. The carburetor exhibited worn material on the float needle valve, float adjustment out of limits, and an improperly adjusted economizer jet. The right rear seat cable assembly had a separated swaged fitting, which was not located; corrosion and wear were absent, and the cable strands showed tensile overstress failure.
Aircraft logbooks indicated the carburetor was last overhauled in 1967 and installed in January 1968. The engine was overhauled in 1976, but the carburetor had not been overhauled since 1967. A non-mandatory service bulletin requires carburetor overhaul every 10 years or when the engine is overhauled, whichever occurs first.