What happened
Multiple instances of white contaminants were discovered within fuel drums and refueling system filters. These incidents involved drums produced by a single manufacturer. The material found in the filters and drums shared characteristics with similar contamination events recorded in 2015.
The investigation
Testing of the white material revealed it to be sealant from the lids or bases of the drums. Laboratory experiments conducted by the ATSB showed that Jet A1 fuel causes the sealant to degrade. The manufacturer of the sealant noted that the material is not intended for contact with solvents like Jet A1 and must stay within the drum seams to function correctly.
Researchers found that when the sealant is submerged in fuel, vibrations cause it to break down into fine particles. This process explains why larger fragments were trapped by coarse 'rock catcher' filters, while much smaller particles passed through to accumulate on micronic pre-filters. The investigation also considered that transport on uneven roads could cause drums to deform, creating gaps in the seams that allow sealant to escape.
Findings
- The primary cause of the contamination is the breakdown of drum sealant due to exposure to Jet A1 fuel.
- Vibrations during transit likely facilitate the release of sealant particles from the drum seams.
- There is no evidence that the sealant dissolves into the fuel or alters its chemical properties.
- To date, there have been zero reports of this contaminant reaching an aircraft engine or affecting aircraft performance.
- In all documented cases, standard fuel filtration systems successfully intercepted the particles.
- While extremely small particles could theoretically bypass micronic filters and reach aircraft tanks, they are expected to be in quantities too small to impact engine operation, provided that regulatory filtration practices are maintained.