Aviation's Hidden Threat

Casual fuel contamination undermines the safety of aircraft and passengers

Noncompliance with our industry’s standards brings tremendous risk.

It is due to incidents like the following that ATA-103 was modified to require grade dedicated equipment and therefore should be a fuel supplier’s policy:

The QC training team was onsite at a dealer’s location when a transport truck arrived to deliver a load of jet fuel.

They took the opportunity to use the delivery as a training exercise. During the visual inspection of the fuel they saw a brown scum lining the bucket. Multiple samples were drawn after wiping the bucket clean but the scum returned every time. They asked the delivery truck driver about the previous load. He indicated it was jet fuel. They asked what was on before that and again he indicated jet fuel.

Then they asked about the previous load to that and the driver admitted hauling biodiesel which contains FAME (fatty acid methyl esters). Further investigation revealed that the truck had hauled biodiesel, and then two separate loads of jet fuel from the suppler that does not require grade dedicated equipment to one of their branded FBOs that did not inspect the fuel before it was delivered. They refused the delivery before it was put into our FBO’s tank. The FAA and aircraft engine manufacturers take FAME contamination very seriously.



Even the automotive industry is concerned about “casual” contamination. In a study released in September by the Battelle Memorial Institute sponsored by the Petroleum Equipment Institute (PEI), carry-over contamination of ethanol from transport trucks was sighted as a possible link in the severe and rapid corrosion caused by microbial growth that has been observed in systems storing and dispensing ultra-low sulfur diesel (ULSD) since 2007. (We’ll post a link to the study in our online version of this feature.)

Untrained drivers are not aware of the risks associated with hauling aviation fuel. They don’t know what they don’t know. Clean trucks, residual fluids from previous loads and clean hoses are not a concern to them. Some drivers believe that all aviation fuel is the same and therefore it is OK to mix avgas and jet fuel.

Wilcoxson related another incident when a driver attempted to make a delivery, and he noticed that the driver was having a very difficult time wrestling with the delivery hose he was going to use.

“I grabbed the hose from the driver and it felt very heavy,” relates Wilcoxson. “So I took the cap off the end and discovered the hose was full of automatic transmission fluid. It scares me to death to think of what could have happened if we had not discovered his mistake.”

Wilcoxson knows that even the best of aviation fuel filters on tanks farms, refuelers and aircraft will not stop chemical contaminants.

We wonder if several different cases we have seen might somehow be related to “casual” contamination of fuel from the residue of previous loads when suppliers do not use grade dedicated delivery equipment. These include corrosion in aircraft wing tanks, gross amounts of microscopic particles in aircraft fuel filters and clear evidence of the effects of microbial growth.

I also wonder about aircraft operators who may have had to complete an engine hot section overhaul hundreds of hours before it was due caused by deposits in the engine. I know from experience that chemical contamination of aviation fuel can cause deposits in the hot section leading to cracking of components. One of our helicopter customers experienced this and determined the root cause was that his suppler had used delivery trucks that had previously hauled lube oils.



Training drivers of the important differences in handling aviation fuel takes time and resources, as does confirming that the individual driver is actually trained and that the trucks are grade dedicated before the load is dispatched.

We Recommend

  • Company


  • Article

    The Responsibility of Q.C.

    The Responsibility of Q.C. From the refinery to preflight, fuel must be continually monitored By Vern Triebel, Quality Control Director, Phillips 66 Aviation October 2000...

  • Article

    A Concern With Biodiesel

    Fuel quality control veteran outlines issues related to transport of emerging fuels

  • Article

    Emphasis on Fuel Quality

    Emphasis on Fuel Quality Oil industry veteran walks through the fuel delivery, handling process By Fred Barnes, Manager of Aviation, Product Engineering, Chevron Products Company...