What happened
During the flight, the pilot identified a fuel imbalance, noting that a higher volume of fuel remained in the left main tanks compared to the right. As the flight progressed, the fuel in the right main tanks was exhausted, resulting in the loss of power to both engines. Consequently, the pilot was forced to perform a forced landing.
The investigation
Subsequent troubleshooting of the aircraft's fuel system revealed that the left fuel selector valve had not actually been seated in its proper detent. Because of this, both engines had been drawing exclusively from the right main tanks. Investigation into the valve mechanism showed that the O-rings within the fuel valve had deteriorated significantly. This deterioration caused the internal spool valve to provide tactile feedback that felt as though it was in its correct detent, even when it was not properly positioned.