A Piper Chieftain took off with an unsecured fuel cap, and the pilot had to conduct a single-engine landing in Meekatharra, Western Australia, after the right engine was starved of fuel, an ATSB investigation report details.
On 5 June 2025, the Shine Aviation-operated, twin-engined Chieftain was being used for a multi-leg passenger flight, planned from Geraldton to Carnarvon, then Meekatharra, before a return to Geraldton.
After an uneventful flight to Carnarvon, the aircraft was refuelled to full capacity by a local supplier, who replaced the fuel caps on all four tanks after the refuelling was completed. The aircraft then took off with the pilot and two passengers on board.
During the instrument approach to Meekatharra, the pilot observed the right low fuel flow warning light illuminate.
Soon afterwards, the right boost pump inoperative warning light illuminated, and the right engine commenced surging, with associated aircraft yaw.
The pilot performed engine failure checks and feathered the propeller. They abandoned the planned circling approach to Meekatharra’s runway 27, and instead accepted a 5 kt tailwind to conduct a straight-in approach to runway 09, landing without further incident.
An ATSB investigation concluded the aircraft’s right engine was starved after fuel siphoned out of the right inboard fuel tank.
“The pilot recalled they visually inspected all fuel caps after refuelling in Carnarvon, but they did not physically inspect them, as required by the pilot’s operating handbook and company procedures,” ATSB Director of Transport Safety Stuart Macleod said.
“The aircraft then took off with the right inboard fuel cap incorrectly secured, which led to fuel siphoning overboard in flight, draining the tank.”
Mr Macleod noted the illumination of the right low fuel flow warning light was due to the low quantity of fuel in the inboard fuel tank, but that the tank’s quantity gauge still incorrectly showed fuel remaining, because the fuel siphoning had collapsed the fuel cell within the wing.
“This overreading of the fuel tank quantity led the pilot to believe they had sufficient fuel for the right engine,” Mr Macleod said.
“But they were unaware that a fuel starvation event was already in progress.
“The pilot was also unaware of the actions to be taken on illumination of the low fuel flow warning light, and therefore did not switch tanks or crossfeed as required by the pilot’s operating handbook, which in this case would have maintained the flow of fuel to the right engine.”
The investigation identified the operator’s training for Chieftain pilots did not specifically highlight the low fuel flow warning in the pilot’s operating handbook, or address the actions required by the pilot on the illumination of the low fuel warning light.
“Not recalling, or being unaware of, the cautions, warnings and limitations detailed in the pilot’s operating handbook can allow system issues to go unnoticed until they escalate, sometimes during a critical phase of flight,” Mr Macleod said.
“An awareness and understanding of these details can enable pilots to identify and respond to any problems that may arise, prior to them escalating further.”
Mr Macleod said operators also play an important role to ensure their pilots achieve competency requirements.
“This includes ensuring pilots receive comprehensive training that develops and reinforces aircraft specific system knowledge.”
Since the occurrence, Shine Aviation has taken several steps to address this safety issue, including revising its training programs and examination processes.
In addition, following a repeat incorrect cap fitment in October 2025, the operator also elected to replace the fuel cap as a precaution, with no further incidents reported.
“An unsecured or incorrectly installed fuel cap can result in significant fuel loss in flight, potentially leading to an abnormal or emergency situation,” Mr Macleod concluded.
“Checks of fuel system security including fuel caps should be conducted by the pilot during pre-flight, turnarounds and after refuelling to ensure correct fitment.”
Read the final report: Fuel starvation involving Piper PA-31, VH-PGO, 28 km west of Meekatharra Airport, Western Australia, on 5 June 2025