What happened
As the aircraft approached its destination, the pilot performed a switch from the right fuel tank to the left fuel tank. Approximately five minutes following this switch, the engine suffered a total loss of power. While attempting a forced landing approach, the aircraft struck electric powerlines before colliding with the ground.
The investigation
An on-scene examination of the aircraft determined that there was no fuel remaining in any of the fuel tanks. Investigators found approximately 1/2 ounce of fuel in the fuel sump, but no fuel was present in the carburetor.
Upon inspection of the main fuel tank bladders, the outboard, top section of the left bladder was found to be folded over and collapsed. The pilot reported that the fuel gauges were non-functional. Further research into the fuel gauge sending units, which are positioned near the wing root, indicated that these units provide a reading of the left fuel tank volume level based on the fuel level rather than the actual quantity of fuel present.