"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."
An Eurofly Airbus A320-200, registration I-EEZG performing flight GJ-1844 from Milan/Bergamo Al Serio (Italy) to Sharm el Sheikh (Egypt) with 179 passengers and 6 crew, diverted to Rome Fiumicino (Italy) after the crew received "fuel filter clogged" indications for both engines. The airplane landed safely on runway 16R about one hour after departure from Milan/Bergamo.
Jet-fuel fungus was found to be the culprit after the US Federal Aviation Authority, for example, issued a bulletin recently to principal maintenance inspectors describing how a major carrier had several incidents in which as many as four take-offs were aborted on one aircraft. Responding to these incidents, along with filter clog warnings, laboratory evaluations were made of the filters.
The cause in each case was determined to be fuel filter fouling caused by microbial contamination. Using microbe-testing kits, an inspection of 27 aircraft in the carrier's fleet resulted in similar instances of fuel contamination.
In February 2004, the CAA received notification that some aircraft were experiencing fuel filter bypass indications on medium-large transport aircraft using Jet A1 fuel. Subsequent inspections found that the filters contained a black sludge/film. Inspection of other aircraft found similar results to varying degrees.
Analysis of the fuel tank samples indicated that the microbiological (fungi and bacteria) contamination was very slight. One sample showed a 'very heavy' concentration of yeast.
A further fuel tank sample was independently tested and found to contain copper, sodium and iron.
Note: The December 2003 fuel filter blockages indicated that there was a high concentration of carbon in the fuel samples. The February 2004 samples do not have similar indications.
Aviation fuel additives are compounds added to the fuel in very small quantities, usually measurable only in parts per million, to provide special or improved qualities. The quantity to be added and approval for its use in various grades of fuel is strictly controlled by the appropriate specifications.
n the U.S., sulfur content of highway diesel fuel will go from 500 ppm S (wt/wt) to 15 ppm S (wt/wt) by mid 2006. The average sulfur content of gasoline will be limited to 30 ppm S (wt/wt) beginning early 2006. Off-road, marine, and locomotive diesel fuel will contain 500 ppm S (wt/wt) to approximately 3000 ppm S (wt/wt). Jet fuel will also contain several-thousand-ppm sulfur for the near future.
As mentioned above, surveys show that the sulfur content of most fuels is well below specified limits. All of the surveys show that about 90% of fuels have sulfur content less than 0.1%. Figure 7-36 shows the historical trends for the U.S. and UK surveys. In the UK, average sulfur level has remained relatively constant since 1988 (Rickard and Fulker, 1997); in the United States, however, the average sulfur content in the NIPER survey has been increasing. This trend conflicts with reports (Hadaller and Momenthy, 1993) based on projections of increased hydro-treatment to reduce sulfur in gasoline and diesel fuel. However, changes in gasoline production have not significantly affected jet fuel because there is very little overlap in the boiling range.
The impact of the trend to use low-sulfur diesel fuels is not clear. Many refineries worldwide do not have the hydro-treating capability to make low-sulfur fuels. The API/NPRA survey for 1996 reported that 46% of the jet fuel blendstock in the United States was straight-run material that was not hydro-treated (API/NPRA, 1997). For many of these refineries with limited hydro-treating capability, the most economical approach may be to shift blending stocks with higher sulfur content to jet fuel, saving streams with lower sulfur for diesel fuel.
Environmental advocates also point to links between high-sulfur jet fuel combustion and local air pollution, while others claim "excessive" cirrus cloud formation (linked to global warming) might be caused in part by jet-engine sulfate particles. These issues might prompt some jet-fuel sellers to tout "green" ultra-low-sulfur jet fuels.
Metal de-activators suppress the catalytic effect which some metals, particularly copper, have on fuel oxidation.
Originally posted by gerktron01
well, since i work at an airport, i think this is completely bogus. the jet fuel we sell is Jet A. it is pre-mixed with prist, an anti icing agent. and when i refuel the plane, there are only 2 wing tanks and a center tank on CRJs. if they get chemicals every time they land, i would know about it. i see the fuel from when it gets off the semi trailer, to when we put it in the fueling truck to when its sent into the plane via single point or over wing nozzles.
just my $.02
[edit on 24-3-2009 by gerktron01]
Consequently, a NOTAM was issued on 23 February 2004 advising aircraft operators to monitor Jet A-1 aircraft fuel filters with extra vigilance.
29th October 2005, 16:58
Recently we've had a high speed abort because of the FILTER BYPASS light illuminating during T/O. (734)
Of course the Captain was called by the boss for a coffee no biscuits meeting.
Besides that, your thoughts would be appreciated on the following:
is it right to say that if the fuel is really contaminated, the first thing to be clogged will be the booster pumps filter?
That illumination of the Filter Bypass light alone is virtually impossible?
We've had several false cautions last year with this problem, and it always was a faulty indication.
How the dirt in the fuel could block the filter in the MEC without accumulating first at the booster pumps filters?
Originally posted by Phage
reply to post by doctordoom
Did you even read the replies to what you linked? Once again, the filters are doing their jobs.
You claim contaminated fuel has something to do with "chemtrails" how can that be if the contaminants never make it to the engines?
[edit on 3/24/2009 by Phage]
I have been an A&P technician on Jet Transport category aircraft for 30 years.
I have never seen a dual failure on any redundant system . (i.e # 2 FMS fails and #2 or #3 fail at same time?)
FAEDC has been used on many many Airplanes and Helicopters for many years. The redundancy built in to these precludes such a failure. I have been an A&P technician on Jet Transport category aircraft for 30 years. I have never seen a dual failure on any redundant system . (i.e # 2 FMS fails and #2 or #3 fail at same time?)
The magic word again is China. The subject of the dead Boeing777 is showing early signs of fuel contamination as to primarily fuel/water ingestion. The flight originated in China.
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.
Filters frequently encounter unknown contaminants or harsh operating conditions, resulting in filter failure. The SwRI aviation filtration facility can simulate a wide range of conditions to duplicate the problem and determine the causes of the difficulty. SwRI staff can also visit the site to assess conditions that may contribute to filter or component failure.
Originally posted by Phage
reply to post by doctordoom
It is now confirmed that you have no idea what you are talking about.
Fuel System Icing Inhibitor (FSII) is an additive to aviation fuels that prevents the formation of ice in fuel lines.
Chemically, FSII is an almost pure (99.9%) ethylene glycol monomethyl ether (EGMME, 2-methoxy ethanol, APISOLVE 76, CAS number [109-86-4]), or glycol monomethyl ether]] since 1994
2-Methoxyethanol is used as a solvent for many different purposes such as varnishes, dyes, and resins. It is also used as an additive jet deicing solutions.
2-Methoxyethanol is toxic to the bone marrow and testicles. Workers exposed to high levels are at risk for granulocytopenia, macrocytic anemia, oligospermia, and azoospermia.