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Jhogan0101 02-13-20 06:42 PM

Filtering Fuel?
I was thinking about filtering fuel with this product while refueling.

Does anyone have experience with it? Does anyone else filter fuel use a different product?

JimC 02-14-20 12:20 PM

I think you're solving a problem that doesn't exist, as well as significantly adding to the fire hazard of refueling. The safety of refueling depends on a metal fuel nozzle touching a metal tank filler ring to help prevent static buildup and discharge.

Jhogan0101 02-14-20 12:25 PM

Jim, i have a grounding strap. How do you know the fuel you are putting into your tanks is free of water and contaminants? Julian

patrolpilot 02-15-20 09:59 AM

If you need or think you need a funnel like that, I'd find a different fuel source. Personally, I only buy from reputable FBO's and that does not rule out self-serve fuel.

One tip I've always held on to as a professional pilot is that if you cannot read the manufacturer's printing on the fuel hose, don't use the source as that is a primary indication that the fuel system is not being maintained over the long run. Hoses have a life, just like filters.

Jhogan0101 02-15-20 10:07 AM

Can a reputable FBO get a fuel delivery that has water or contaminants in it? I agree the chances are very low, but i think it is possible. As i fly to different places with the funnel, ill document and post the results.

n86121 02-15-20 11:07 AM

As an airport owner in the USA
In USA anyways, the AVGAS supply chain is tightly controlled from source to airplane.

Obviously the stuff is manufactured in magical places, then stored regionally in huge large distribution tanks.

Then the fuel trucks carrying avfuel only carry avfuel, nothing else.
So nothing else gets mixed in during transport.
And they are periodically internally washed.
So the trucks are clean.

Our airport fuel tanks then have water detection starting 0.1 inches from the bottom of the tank. And the actual fuel takeoff is about 4 inches from the bottom.*
All remotely monitored and alarmed.

Each of our fuel dispensers then has its own $2,000 filter and housing at the connection to the hose. In addition to catching any solids, the filters are similar to VERY EXPENSIVE baby diapers: Like water filters used on boats they capture water. Should they get saturated by water they will block fuel flow before letting any water through. The dispenser will get slower and slower and then stop, but no water gets through. The housing also has sump drains IF water gets trapped. In many years I have never seen any. The fancy-schmancy filter housing also have sight gauges: If any water occurs it drools down to the bottom of the housing and the little white ball floating in blue fuel goes ..white.

Fueling out of a metal drum in the 3rd world probably a little different.


As most know, the more likely water hazard is condensation in un-filled tanks.

Also, blocked through-wing drains can allow the little 'swimming pools' around each fuel filler to fill with water, which can then drain past the caps.

I always carry 2ft pipe cleaners and drool a bit of fuel when refueling, to make sure the drains are clear. if not, out comes the pipe cleaner until they drool.

And then we have sumps.


You can now see why we don't handle autogas. Neither the supply chain nor the product are controlled, and the airport would be in the liability chain.


*I think auto gas station tanks also have about a 4 inch takeoff from the bottom of their tanks, below which accumulates all sorts of terrible things. Those terrible things get stirred each time a tanker refuels the tanks, which can take a while to settle back down into the abyss. Which is also why I try to avoid refueling cars if a gas station's are or have been recently refilled.


Possibly the original source of ethanol craziness - In the 3rd world gas stations, they quickly realized they could intentionally add water, reducing their cost per gallon, until cars quit. And they could blame the fuel. I am 99% sure someone said, "Hey, thats a great idea!" And then the environmental movement went "Ooo, ethanol is more natural!" And then the industry said, "Cool, higher price per gallon and less energy per $ = higher margin. EXCELLENTO!"

But I digress.

Jhogan0101 02-15-20 11:30 AM

Great info Dave. With that said, im a big fan of “trust but verify”

JimC 02-17-20 08:39 AM


Originally Posted by Jhogan0101 (Post 24425)
Jim, i have a grounding strap. How do you know the fuel you are putting into your tanks is free of water and contaminants? Julian

I'll flip it around:

What evidence do you have that contaminants in FBO fuel are causing problems in GA aircraft?

Jhogan0101 02-17-20 08:59 AM

Last year i flew cross country from SLC. Stopped to refuel in Nebraska, just before taKe off roll the rear engine quit for some unknown reason. The take off was aborted, rear engine was restarted and all was fine. There are many things that could have caused this.
I have to admit im a bit of a nerd when it comes to reading ntsb accident reports. The ones where fuel/engine issues were involved that were inconclusive, i cant help but wonder that maybe there was a problem with the fuel. It most likely wasn't but who knows.
As i fly i will document fuel quality and update this post.

patrolpilot 02-17-20 09:22 AM

1 Attachment(s)

Originally Posted by JimC (Post 24445)
What evidence do you have that contaminants in FBO fuel are causing problems in GA aircraft?

Fuel contamination in the US is not an issue.

I'm going through a CFII refresher, working on a ME add on, and NTSB accident statistics were presented for a decade ending in 2016 (the latest available as settling all causes takes about two years). The attached images are those relating to fuel. The black bar are fatal accidents.

There were two General Aviation accidents related to fuel contamination in that decade and I'm willing to bet that the fuel was not delivered that way. It is possible the contamination came after the fact from extreme condensation within the fuel tanks or an external source like rain or melting snow.

You are 15 times more likely to come up short with planning the fuel for a flight, I'd say especially with a 337 because of the inability to see into the tanks. Same with mismanaging the fuel load, there have been a number of these in pre-"G" Skymasters.

I think my recommendation of avoiding fuel contamination is the best bet. If you cannot see the lettering on a fuel hose, don't use it. If you need it, have the FBO provide a clean bucket and buy a gallon to run the "Clear & Bright" test yourself. That gallon will reveal any contaminants.

Aviation, these types of things, have always been self-policing, at least in this country. I don't have a problem letting the FBO know that they have sloppy practices.

patrolpilot 02-17-20 09:48 AM

I will add that if contaminates ended up in my fuel tanks, I sure would buy that funnel to drain the fuel through.

Brings up another thought. If you ever need 55 gallon poly barrels, go to an AG airplane operator. They always have too many of them. Here, they will give you a truck load of them. They even gave me two, 250-gallon square tanks that have the external tubing frames.

n86121 02-23-20 09:50 AM

I am a private citizen not bound by gov procurement to requirements-only, and a pilot, so at Potomac I went with the Rolls Royce of fuel filters on the end of each dispenser.

Many airports may not have done so.

As I recall each filter housing was around $1,500 maybe 10 years ago, and we have four dispensers. That wasn't including the filters.

Because they have an easy visual check, and a simple drain valve should any water be present, we haven't had to touch them.

Again, many airports may not have wanted to drop nearly $10k on dispenser filters.

hharney 02-23-20 05:53 PM

I don't want to jinx myself but 44 years of flying the same 337 and I have never has a contamination issue with fuel. Water in the sumps, sure, many times but that's why there are sumps and the checklist says to check them. I think there are better items to worry about.

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