Two pilots experienced engine surging and declared a mayday after inadvertently exhausting the aircraft's auxiliary tanks, an Australian Transport Safety Bureau investigation notes.
On 18 August 2022, an instructor and trainee instructor were operating a Cessna 310R during a training flight from Redcliffe Aerodrome, Queensland when the engines started surging alternatively.
The instructor declared a MAYDAY and began tracking for a forced landing at Sunshine Coast Airport, but during troubleshooting on descent, the crew switched from the auxiliary to the main fuel tanks, and the engine issues were rectified. The crew then conducted an uneventful landing.
An ATSB investigation found the auxiliary tanks had been exhausted, resulting in fuel starvation and engine surging.
"The pilots did not establish the amount of fuel on board prior to the flight, or manage the fuel state throughout the flight," ATSB Director Transport Safety Dr Stuart Godley said.
"Both pilots were unaware of the fuel system configuration of the Cessna 310R, believing the aircraft was fitted with larger auxiliary tanks than was the case."
The incident aircraft had a 140L usable fuel auxiliary tank capacity, but the instructor assumed it had the same 238L capacity as other Cessna 310 aircraft they had flown.
"The ATSB also found the operator had inconsistent and incomplete technical documentation for the aircraft, and the aircraft's fuel selector plaques contained contradictory and incorrect information about the capacity of the auxiliary tanks, and in different units," Mr Godley added.
Since the incident, the operator - Aircraft Australia - has implemented a new fuel log specific for the Cessna 310R.
Additionally, an internal memo has been distributed outlining the changes to the data sheet for the Cessna 310R to ensure all pilots and students are aware of the fuel configuration of the aircraft.
The operator has also requested fuel selector plaque replacements, to ensure the correct labels are installed.
Dr Godley welcomed the safety actions taken by the operator, but emphasised the incident's relevance to all pilots.
"Accidents involving fuel mismanagement are an ongoing aviation safety concern, and are a reminder of the importance of monitoring fuel levels prior to, and during flight," he said.
A selection of fuel management related incidents, and their safety lessons, have been previously published by the ATSB in the publication Avoidable Accidents No. 5.
Dr Godley also noted methods for cross-checking fuel on board before flight are published by the Civil Aviation Safety Authority in its Advisory Circular AC 91-13v1.1.
You can find here the ATSB's report: AO-2022-040 Fuel starvation event involving Cessna 310, VH-JQK, near Sunshine Coast Airport, Queensland, on 18 August 2022
