What happened
On December 9, 2016, during a pre-flight inspection at the Białystok airport (EPBK), the crew of a Cessna 152 discovered that the aircraft's fuel was contaminated with a greasy substance. The contamination was identified through the analysis of fuel samples taken from the aircraft's fuel tanks during the draining process.
Upon discovery, the refueling process from the tanker truck was immediately halted. An inspection of the tanker and its associated documentation was subsequently conducted to identify the source of the impurity.
The investigation
The investigation, conducted by the operator, focused on the refueling infrastructure and the fuel supply chain. The examination of the tanker's delivery system revealed that one of the metal filters located within the tanker's discharge line was contaminated. Further inspection of this specific component showed that the filter mesh had been breached, allowing foreign matter to enter the fuel stream.
Findings
- The primary cause of the incident was the damaged and contaminated metal filter within the fuel delivery tanker, which allowed a greasy substance to pass into the aircraft's fuel tanks.