What happened
The pilot reported that he was operating under Visual Flight Rules (VFR) but had "gotten into IFR conditions." Although instructed to maintain VFR at all times, the pilot continued his own navigation and changed radio frequencies. Shortly after, the pilot issued a mayday call, after which all radio communications were lost.
Ground witnesses observed the aircraft's engine backfiring and sputtering. The PA-32RT-300 was seen at a low altitude in a left bank when the left wing struck a tree; discolored foliage was noted near the impact site.
The investigation
Examination of the wreckage showed that the left fuel tank had been breached and contained no fuel. The right fuel tank was not breached, and less than 1/2 gallon of fuel was drained from it. Investigators found the fuel selector set to the "right" tank and the electric fuel pump switch in the OFF position.
The aircraft's last known fueling occurred on 8/26 with 50 gallons of fuel. Based on Hobbs meter readings, the aircraft had flown a total of 6.1 hours from departure until the crash. At a fuel burn rate of 18 gallons per hour at 75 percent power, approximately 110 gallons of fuel were consumed during the 6.1-hour period. Calculations indicated that approximately 48 gallons of fuel should have remained at the time of impact, while the total usable fuel capacity for the two tanks was 94 gallons (47 gallons per tank).