What happened
A pilot and a certified flight instructor (CFI) were conducting a training flight when the aircraft's engine lost power on three separate occasions. During the first two instances of power loss, the pilot successfully restored engine power by switching fuel tanks. However, following the third occurrence of power loss, the pilot was unable to restart the engine.
Prior to takeoff, the pilot performed a visual inspection of the fuel and estimated that approximately 30 gallons of fuel were available in the tanks. Both the pilot and the CFI reported that the aircraft's fuel gauges indicated adequate fuel levels throughout the flight. The total duration of the flight was approximately 45 minutes.
The investigation
An examination of the aircraft following the crash revealed that the fuel tanks were empty.