What happened
During a flight in a Cessna 3-10R, registration VH-JQK, the crew experienced engine surging and observed fuel streaking from the main tanks. The engines recovered once the fuel selectors were switched from the auxiliary tanks back to the main tanks. The event occurred after the crew had operated on the main tanks for approximately 30 minutes before switching to the auxiliary tanks. While the engine consumption alone was not sufficient to deplete the auxiliary tanks, the transfer of unused fuel from the fuel pumps into the main tanks accelerated the depletion of the auxiliary supply. This process caused the main tanks to become full, with excess fuel venting overboard, while the auxiliary tanks eventually ran dry, resulting in fuel starvation.
The investigation
The investigation focused on fuel management practices and the accuracy of technical documentation. It was found that the crew did not establish the total fuel on board prior to departure, as the aircraft journey log was not updated. Furthermore, the crew failed to adhere to the operator's requirement to perform fuel quantity checks every 30 minutes, and neither the instructor nor the trainee could recall the fuel gauge readings during the flight.
Additionally, the investigation identified significant discrepancies in the operator's documentation. The operations manual contained inconsistent fuel flow rate data and lacked specific details regarding the fuel tank configuration for this particular aircraft variant. The fuel selector plaques on the aircraft also contained contradictory and incorrect information regarding auxiliary tank capacity.
Findings
- The instructor lacked familiarity with the specific fuel capacity of VH-JQK, incorrectly assuming the auxiliary tanks held significantly more fuel than the actual 140 L capacity.
- The trainee instructor relied on the instructor's previous experience with other Cessna 310 models rather than performing a proper familiarization with the current aircraft's fuel system.
- The operator's technical data sheets provided generic fuel flow rates that did not accurately reflect the requirements for the Cessna 310R variant.
- The pilots failed to follow established pre-flight and in-flight fuel management procedures, including the use of a fuel log and regular cross-checking of fuel quantities.