What happened
The pilot landed at a field site to collect two passengers. Following this landing, the pilot drained the fuel from the left tank for future storage. According to the operator, this is a standard procedure, and as a consequence, their aircraft are typically operated with the fuel selector valve set to the right fuel tank position.
During the return flight, approximately five minutes before reaching the destination, the engine stopped producing power. The pilot subsequently landed the unspecified aircraft, which resulted in a nose-over. The passengers noted that the return flight was characterized by turbulence and that the pilot did not perform a fuel tank dip prior to departure.
The investigation
An examination of the fuel levels following the accident revealed that the right fuel tank contained 7.3 gallons of usable fuel, while the left fuel tank contained 3.1 gallons of usable fuel. Following the incident, the engine was started and found to be operating normally.