This whole Fungal Growth in Fuel thing.

[Ganyeka]

Firstly, I am not a Pilot. I am a lawyer. That alone may be grounds on which to hang, draw and quarter me. I do have 2 close friends who are Pilots, both with Virgin Blue. I don't know if that helps.

The reason for me posting on this forum is slightly obscure. I have a client who is, amongst other things, an inventor. He is very intelligent, but, how do I say this delicately, he's "unconventional". He recently posted as Fungal Bob in your Tech Forum about fungal growth in fuel and was roundly criticised. I believe his intentions to have been honourable. He isn't trolling or spamming for commercial benefit. He has connected some dots and become concerned by the inferences he has drawn. He does have existing technology that is relevant to fuels and specifically to microbial contamination, hence his interest. He is one of these guys who genuinely wants to help.

I'm trying to get my head around the issue and thought I might humbly seek the views of this Forum's members.

I cannot technically assess the merits of the various arguments but a few things seem clear. At the risk of over-simplification, microbial contamination and fungal growth in aircraft fuel seems well recognized. It's effects are known to be problematic for engines and other parts due to corrosion, blocked filters (and one therefore assumes fuel delivery), wing electrics and structural elements etc. Whilst there seems to be maintenance routines for detection and correction and various additives to combat this microbial contamination, it seems clear that it does, nonetheless, routinely cause both minor and serious safety concerns.

It also seems clear that these procedures for detection, correction, repair and prevention are challenging and frequently expensive. And, as with all of these types of systems and procedures, if they aren't followed properly, or something goes wrong whilst performing them such that they are imperfectly performed, the consequences can be severe.

Any issues so far? I'm just trying to lay some groundwork and establish what my understanding of the situation is.

So if this issue really is as potentially serious as it seems to be, isn't an alternative solution that is basically 100% effective, cheap and essentially permanent something people would be interested in?

I'm just asking. And I am asking genuinely, not as a prelude to a product flog etc. I am just trying to understand the dynamics of the problem and the politics etc surrounding how it is currently handled.

Cheers and Thanks, in anticipation.

[vapilot2004]

Nothing to add of substance

I've always been amazed at how something as noxious as jet fuel & kerosene can still manage to support life.

[piggybank]

There are lab checks that can be done and are done to check bulk fuel installations for fungus.

Good care of the tanks of fuel, i.e. ensuring water drain checks are done on a daily basis. Here at my location we fill from tank-tainers containing 20 thousand litres that have been at sea. The fungus and quality lab checks are done on receipt of a new container, before going into bulk storage.

Boron compound treatments have been successful in the past in treating bulk fuel and affected aircraft fuel tanks and for prevention of fungus development.

However, some engine manufacturers have limits of how much boron from these compounds can be tolerated by the turbines of their particular engine during its working life.

[MountainBear]

My problem with the original post is when it uses words like "serious" and "severe". There is no context for evaluation.

If a wing falls off a plane that is a serious and severe problem. Fungi growth in fuel, eh, not so much.

[matkat]

As a maintence engineer I can tell you that regular checks are carried for fungal growth, not only that a chemical (bibor) is also regularly added to the tanks to kill it.

[Meccano]

The microbes can cause damage to the tank Mountainbear. It seems they not only can survive in kerosene - but they also 'eat' aluminium. I know of one B732 back in the early 80's that had to be scrapped because of it (African company).

[Los Endos]

As far as I'm aware many commercial fuels contain additives such as Prist which prevents fungal growth and lowers the temperature at which crystilline icing occurs. If not already present in the fuel it can be added at the point of delivery.

[piggybank]

https://www.corrdefense.org/Academia...try/06T025.pdf

The above link seems to cover the subject of fuel tanks with fungal activity in the fuel, and as far as I know the fungus only developes at a fuel water interface so you have the one of the ingredients for corrosion right there.

[MountainBear]

The microbes can cause damage to the tank Mountainbear.

Since you seemed to have missed my point entirely let me try again.

Link a single accident report anywhere in the world where fungi in the fuel supply--either directly or indirectly--lead to a loss of life.

I know of none. It seems hyperbole to claim that this is a "serious" or "severe" problem from a safety perspective. Even if you want to argue that, left untreated, it would become a safety issue that only speaks to the fact that present methods seem to be taking care of the safety aspect nicely, thank you very much.

None of this should be read to disparage the inventors knowledge. It may be the case that there are real cost saving involved by adopting his product. That amounts to a claim that product X is better than product Y. I don't know enough to judge that claim.

What I do know is that given all the real issues in flight safety--CRM, automation, exploding Rolls Royce engines--attacks by the mutant fungi from outer space are low on the list.

[Ganyeka]

Flight Safety Australia had an article in the September/October 2005 edition called "Attack of the Funghi" which states that the funghi causes the formation of a "gooey matt" which can "cause blocking of the engine fuel feed system". This is unlikely if good maintenance is being performed (a big "if" in many operations and parts of the world), but the article goes on to state that the real problem is "corrosion to the wing structure". This corrosion happens in a number of ways that the article details, such as:

1. reducing the surface tension of the water so that it spreads into small gaps more effectively;
2. acid byproducts reacting with the chromate in primer paint turning it into a passive form so it will no longer sacrifice itself to protect the aluminium;
3. increasing the electrical condictivity of the water allowing electrons to flow more easily, accelerating the oxidation process;
4. directly attacking aluminium.

The article was written by an aeronauical engineer. I would consider this to be "severe".

The rest of the article, about detection and treatment, seems to highlight the risks if vigorous maintenace and correction procedures are not undertaken, and the cost of things like cleaning the tanks. Not to mention the environmental impacts of all of these additives and fuel tank cleaning etc.

And here's the thing from my point of view - it's the Jurrasic Park Principal (don't try to look it up, I made it up) - ie - When human generated complex systems require human delivered complex maintenance, it's a question of WHEN not IF something goes pear-shaped. Therefore, anything that simplifies the maintenance and improves the outcomes reduces risk. And when we're talking about aircraft, we're talking about lives. The risk, specifically, is death. Potentially lots of death.

Problem is there seems to be a lot of vested interests in justifying the status quo and lots of businesses built around airplane fuel additives and such who want to push the line that everything works just fine. So who is going to take a proper, objective look at these issues and consider ALL of the alternatives?

Anyway, now I feel like a conspiracy nut, but with even the mainstream media picking up stories about fuel problems grounding planes and causing issues, it makes me wonder if there isn't a bigger issue here.

[27mm]

IIRC, the RAF had this problem on its Herc fleet some years back; the fungi in question, I believe, was called Cladiosporium Resinae.

[JW411]

Several BAe146s have had to be scrapped because of fungal "rot". The damage was so bad that they were beyond economical repair.

The undersurfaces of the wings of those that were repaired were not a pretty sight either - patches everywhere!

[foxy2600]

Fuel Quality

Most good airlines subscribe to the IATA fuel quality programme. If the inspections are done correctly, the fuel supplied 'at the pump' could not support CR as the filtering (C Filter) won't allow microbes through and the filter/separators won't allow water through. The problem lies with aircraft stored for any length of time or extended parking. As one contributor said - poor maintenance. Warm moist hi-humidity climates don't help, which it is more prevalent in the tropics. Biobor and regular water drains help. Purging /draining the fuel system doesn't, as the seals and sealant dry up.
Why does it eat untreated aluminium? It grows on the interface of water and JetA1 and then 'clings' to the tank interior as the levels fluctuate. It's kind of plant form which means Carbon in - Oxygen out. Water enriched with oxygen loves untreated aluminium.
Not the same but just as weird is the bottom of a plastic (fibreglass) boat. keep it in the water for three or more years and the gel coat starts to get 'eaten' - so I guess the all plastic aircraft won't be any better either

[Grogmonster]

Tell us about the solution

Ganyeka,

I would love to know how your friend can solve this fungus issue. Please tell us?

Groggy

[protectthehornet]

in airline ops it seems that you burn fuel so quickly, on a daily basis there isn't much of a problem...in the US all of our fuel has the additive sometimes known as PRIST.

now, if you got fuel without prist, and it sat in the tank for months at at time you might have a problem...but airliners don't sit (in regular service mind you), they fly, they burn fuel and the fuel is replaced later on.

[Agaricus bisporus]

Ganyeka, I rather think the "problem" already has a solution. "Biobor" is a well known and readily available biocide that is used to combat the growth, any new product will only be a competitor to an already established market leader. (Prist is an anti ice additive, not a biocide)
If operators can't or won't be bothered to keep fuel tanks water free then they are unlikely to bother buying Biobor or any other product, so you won't win there.
It is not a thing I've ever encountered in 25 years flying from equator to almost the arctic circle, so I don't lose too much sleep over it.

the bottom of a plastic (fibreglass) boat. keep it in the water for three or more years and the gel coat starts to get 'eaten'

It does? As a plastic boat owner that's news to me! What happens to gelcoat at three years immersion? All gelcoat? Please tell more.

[411A]

"Biobor" is a well known and readily available biocide that is used to combat the growth, any new product will only be a competitor to an already established market leader.

Indeed so.
The first jet airplane (business jet, anyway) to have these difficulties was the Lockheed JetStar, but fuel additives solved the problems.

I think the original posters friend has a solution looking for a problem...that has been solved already.
IE: a financial dead-end.

[SNS3Guppy]

Ganyeka,

Fuel contamination is always a serious issue. Microbial contamination in fuel is a problem not only in aircraft, but in storage and transport systems, as well Delivery from both storage and transfer systems (trucks, underground delivery and so forth) have filters to prevent passing on contaminates.

Microbes in aircraft fuel cells thrive where water is found. Algae and bacteria becomes a problem if the fuel sits and has water available in the fuel (jet fuel suspends water better than other fuels such as gasoline). In aircraft that are constantly on the go, constantly burning their fuel supply and receiving new fuel, it's seldom an issue at all.

Where fuel contamination does take place from organic developments, the corrosion issues are localized to the algae, and are usually not a problem. You mentioned in your original post issues with corrosion of wing electrical components, and so forth. These have nothing to do with the formation of algae and other contaminants in fuel.

I'm a career aviator. I'm also a career mechanic (engineer, to some here). I've worked extensively inside fuel cells, installing fuel cells, repairing fuel cells, etc. I've been a director of maintenance twice. I've been an inspector in repair stations, a line inspector, and filled other maintenance line, floor, and supervisory duties over the past few decades. Fuel contamination, while most certainly a serious issue, is rarely a problematic issue in that it seldom is seen and seldom rears it's head. It's just not an issue as I've seen it over the years, especially for aircraft that are properly maintained and frequently flown. For aircraft that will be stored for a time it can be an issue, but there are numerous considerations to make that determination, and more importantly, it's something that can be addressed.

Another poster mentioned biobor, which is a "shock treatment" for an existing problem in a fuel cell or system. It's also available for ongoing treatment. The most commonly used treatment is the inclusion of fuel additives such as "Prist" in fuel. These are primarily used to affect the freezing temperature of fuel, but they also serve other functions. Often these additives have or include chemicals which offer antimicrobial properties. They tend to inhibit the growth of microbes.

This corrosion happens in a number of ways that the article details, such as:

1. reducing the surface tension of the water so that it spreads into small gaps more effectively;
2. acid byproducts reacting with the chromate in primer paint turning it into a passive form so it will no longer sacrifice itself to protect the aluminium;
3. increasing the electrical condictivity of the water allowing electrons to flow more easily, accelerating the oxidation process;
4. directly attacking aluminium.

The article was written by an aeronauical engineer. I would consider this to be "severe".

While I'd agree that from your perspective this sounds like a terrible thing, it's not.

Corrosion in aircraft comes from a number of courses, including within the metal itself. Galvanic, intergranular, fretting, electrolytical, and numerous other forms of corrosion occur, to say nothing of fatigue, and other factors which are prime concerns to maintenance personnel. You appear to be envisioning a problem in which microbes are on the verge of causing a wing to fall off. This isn't the case.

Pitting on surfaces, and spots of corrosion in faying (overlapping) surfaces can certainly occur. What we're not seeing out there are hoardes of microbes gnawing their way through wings and the wholesale need for replacing wings and aircraft structures due to microbial infestation. It's just not happening.

The wrong soap used on the outside of an aircraft can cause or accelerate corrosion on an airframe. Paint sometimes sustains corrosion. Corrosion is an ongoing process which does not end, and which is a constant battle (albeit a relatively minor one, in the grand scope of things), with which maintenance personnel must deal. Sometimes addressing corrosion means light surface removal of the corrosion, other times it involves repairs of varying degrees. Often it's little more than prevention, which is nearly always the case with fuel tank contamination by microbes. One tests the fuel, deterines the problem, makes a visual inspection where necessary, treats the fuel, flushes the tanks if absolutely necessary, changes and inspects filters, and moves on. We're talking about routine maintenance issues here...not drama, and not a "severe problem." A routine problem.

[foxy2600]

Off Thread - Boat thing

My boat's over 30 years old now. When she's out of the water the hull gets pressure washed and re-waxed. It's all discoloured and shows signs of pitting, just like the older exterior uPVC panels on my house. All the day-fishers I talk to say algae is the cause - I live in ignorance I guess could be an old wives tale but clean her every 3 years or so regardless.

Found this:
Blister Repair Methods

Sure this thread should now be in Tech Log

[foxy2600]

Is someone watching me ??

Must be a moderator reading my mind