Maintenance Error
During maintenance on the fuel selector and manual fuel pump, a sealant identified as 'Fuelube' was used in place of the proper lubricant for the O-ring seals. This substitution was not detected before the aircraft returned to service.
Flight Event
Approximately 10 operational hours after the application of 'Fuelube', the pilot experienced binding in the fuel selector when attempting to switch fuel tanks. The pilot reported being unable to feel the detent position during the tank change. The maneuver was attempted during a cross-country flight.
Engine Failure and Forced Landing
As a result of the binding issue, the engine failed due to fuel starvation. The pilot executed a forced landing to an open field that was strewn with rocks. Upon touchdown, the aircraft sustained substantial damage.
Investigation Findings
The investigation determined that the incorrect material—'Fuelube' sealant instead of the specified lubricant—had been applied to the O-ring seals. This led to the binding of the fuel selector mechanism, which prevented proper fuel tank selection and resulted in fuel starvation.