As questions about fuel monitors continue to circle the industry, the International Air Transport Association (IATA) has provided some answers. IATA is currently responsible for a number of initiatives in the fuel arena with groups currently focusing on jet fuel joint specification — trying to harmonize the A1 (Europe) and A (U.S.) specs — fuel quality, microbiological contamination, and fuel efficiency. As a part of these fuel-focused initiatives, the IATA Fuel Filter Monitor Task Force has come out with a report that says that super absorbent polymer (SAP), a water absorbing media, is not a problem after all. While there is still concern about trace amounts of SAP migrating from the filter monitors, it is minor compared to other debris found on blocked engine fuel filters. According to one industry source, a lack of Federal Aviation Administration (FAA) and European Aviation Safety Agency (EASA) regulation has led to industry concerns over quality and cleanliness procedures.
“Both EASA and FAA indicated that fuel is to be free of contamination,” says an industry source close to the study who also works as an engineer with a major U.S. airline. “Now, there is not such a thing [as] fuel free of contamination.”
This is the beginning of the rub for the industry source, because the engine manufacturers, which control what fuel their engines will burn, have specifications for quality and cleanliness, but the regulations are not reflecting that. What is happening in the meantime is that the fuel moving from the refinery to the airport and into the aircraft wing does not have any regulation either, the source says.
| Contaminants identified on engine filters |
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| • Aluminium • Calcium • Chlorine* • Copper • Iron oxides • Salts •Silicates |
•Sulphurous Material Sulphides Sulphite Sulphates •White cloth fibers |
One of the biggest factors in the U.S. and around the world is the lack of fuel quality regulatory oversight throughout the fuel supply chain, according to the source close to the study.
What is happening in the meantime is that the fuel moving from the refinery to the airports does not have any regulatory oversight except at the supply to the aircraft wing, which is currently required to be free of contamination, the industry source says.
The pipelines are so old and dirty that the fuel inspected at the refinery is not necessarily in the same condition when it is delivered to the airplane, says the source. Oil companies do, however, have checks and quality assurance procedures within the company.
An industry source who supplies fuel filter monitors to FBOs sees it a different way. “I would disagree with [the lack of pipeline regulation],” he says. “There has been a lot of speculation; I know there are a lot of people working on different testing procedures and different processes, but generally speaking, the quality control requirements of a branded FBO are pretty tight.”
The regulation discrepancy regarding fuel contamination comes from the technological transition from the “white bucket test” to the use of fuel filter monitors. “Free from contamination,” — as stated in EASA Part M Subpart C AMC M.A.301 – 1-C and FAA FAR 121 and 135 — has a different interpretation in a naked-eye test compared to a fuel filter monitor reading, due to a 40 micron difference.
According to the task force source, the human eye can see up to 40 microns, so anything under 40 microns passes the “white bucket test” because it isn’t visible. It is visible, however, under a microscope.
“This regulation was written years ago when the only test available was the white bucket test,” says the IATA source. “Because we’re [now] using very accurate devices to measure if the fuel is clean or not, we identify some things that previously would have never been identified.”
e API/IP filter performance standards are much tighter, finer than one micron,” says Jim Gammon, president of Gammon Technical Products. “What makes up the dirt found on aircraft filters is being investigated.”
According to Gammon, it is possible that both fine dirt (through the filters) and coarse dirt (dust from opening the wings for service and the tank vents) are accumulating into larger particles inside the wing itself. He says the airport-based filters should not be passing dirt large enough to plug aircraft filters.
FLAWED SYSTEM
“The SAP problem, if we can identify it as a problem, from the airline’s point of view, was addressed because we get some fuel filter bypass indications,” says the IATA source.
In an effort to ensure that aircraft are not getting this fuel filter bypass, fuel filter inspection removal intervals have been reduced to a fraction of the filter’s original shelf life. “This basically [means] we are losing a lot of money because we are burning the [total] yield,” the IATA source says.
According to the executive summary from the IATA Fuel Filter Monitor Task Force’s report, “the oil companies and filter manufacturers had advised all operators about the need to tighten operational checks on filter monitors including the daily monitoring of filter monitor differential pressure, flow rate, and water drainage of filter vessels, as well as maximum service life reduction of filter monitor elements from three years to one year.”
To this point, reducing the life of fuel filters has had a negative effect on businesses, especially due to a lack of facts. “The difficult thing for me is to tell the customer why they need to change filters a lot more than they had to in the past,” says a supplier of fuel filter monitors to FBOs.
[Customers] call and they want to know the answers and all I can tell them is what I know from regulatory guidance and the fuel filter people. My customers are caught up in the confusion of what, exactly, they need to do, and therefore, they look to me and others in the industry to give them guidance — not only in what they should do, but why they have to do that.”
Explains the IATA source, “[The task force] did identify some minor traces of SAP in our filters, and this is the reason that we took all of these actions with the fuel filter interval replacement; but on the other hand the airplanes are not producing this stuff; this is coming from the refinery to the airplane wing.”
Fuel filter bypass solely by SAP found in the filter has yet to be reported in the industry, the IATA source says. It is a combination of both debris and the SAP, but he asks, where is the debris coming from? The pipelines? The lack of filtering to clean the fuel?
“This is not a new issue; it’s 28 years old,” the IATA source says. “Previous activities were lacking due to no business plan, no money, and the [regulators] left it up to the industry to take action… The industry needs a regulatory authority to say, ‘I want you to find the solution to this.’” He states that such action will force major oil companies and other parties involved to develop a business plan to ensure fuel quality cleanliness.
According to the task force report, there is evidence of SAP found on aircraft filters. Because the material occurs in low concentration, the SAP that was observed acted like a small amount of particulate dirt contamination, and thus did not contribute to filter plugging (relative to other identified contaminants).
PLAN OF ACTION
According to the IATA source there is only one step that needs to be taken. “FAA has to establish a committee in order for the regulation to be changed,” he says. “Instead of saying ‘free of contamination,’ [the regulation should] state ‘in accordance with the engine manufacturers’ fuel specification, quality, and cleanliness.’ That would be more appropriate wording in both EASA and FAR.”
The new standard, as stated in the task force’s report, should “adopt [a] new definition for fuel quality in aviation regulation and airport fuel handling standards.”
“We don’t think it is a high risk [situation], because of the minute traces [of SAP] showing up in the fluid,” says FAA spokesperson Les Dorr. “[FAA] does plan to revise [FSAW 06-04A] to our inspectors and explain that there is something else going on here where the trace amounts are showing, but its not a high-risk amount showing up.” Dorr indicates that FAA doesn’t have a specific timeframe for the new bulletin.
As a result of this possible change, the engine manufacturers would get involved and provide the effects any leakage of SAP may have on individual engines, as well as information regarding acceptable levels of SAP.
A GLOBAL ISSUE
A copy of the IATA Fuel Filter Monitor Task Force’s report has been sent to FAA, EASA, and aviation authorities in Canada, Australia, and others around the world. “This is an international issue,” the IATA source says. “The regulations need to change to reflect the fact that there is no fuel free of contamination. There is always something there. There will be some water, there will be some debris, and it could be within the engine manufacturers’ allowable limits.”
A copy of the IATA Fuel Filter Monitor Task Force’s report is available directly from the International Air Transport Association.
