Wings Forum

Ethanol based Fuel not approved for use in Just Aircraft airplanes.

I'm sure this is a CYA thing, but it really sucks. Where I live ethanol free gas is not available and Rotax discourages 100LL because of the lead build up in cylinders and gearbox. Ethanol is a fact of life now and components should be built to handle it. The auto industry is managing to deal with it, and Rotax approves up to 5%. Come on JA, get with it...

.....and tell those of us who've used fuel blended with ethanol how we should proceed (inspections, replacements, etc.). Originally blended gas was 'ok', after all.

k

Not Cool! Definitely CYA! I've been using ethanol laced premium for more than four years with no problems at all. Rotax recently amended the ethanol maximum to 10% and now Just says "no ethanol"? This is a subject that requires Just to respecify all fuel system components, not prohibit the use of the only available recommended fuel.

Not cool Troy! Try again.

Alan

The ill-effects of ethanol in fuel are well documented. While a total redesign of the fuel system may help, if you leave fuel in your tanks for any period of time it will still be tough on the system.

With that said, Just is taking the high road and covering themselves by telling everyone that, as it stands, they don't think you should use ethanol fuels. If you want to, they can not keep you from using it. Gone five years with no issues? Go for it! If you have a fuel related problem though, it's on you. This is NOT an FAA directive telling you you MUST NOT use it. It is a recommendation by the manufacturer of the kit stating it may not be a good idea with the components involved.

This ethanol thing has been going on for a long time with the fiberglass tanks. Just aircraft has done nothing to stop the problem. The only way to stop it is to change the material the tanks are made of. What would that cost? I don't know, but what will it cost for each owner to remove the tanks and have some made of a plastic of some kind or of aluminum, and then of course redo the fabric over the tank or recover both wings and paint them. Just aircraft could have new tanks designed and made and offer them to owners at cost. I think every owner would bite the bullet and replace their tanks at their own cost.

If you have had an instance of sticking valves (being able to turn the prop through with no compression) you probably have bent pushrods and the intake valves have hit the pistons. The fact you are still flying is testament to the Rotax durability.
Every Just Aircraft needs new tanks, the fiberglass tanks are not working regardless of the "new resin "used in construction.
Who pays for this? Well, Just Aircraft's letter pretty well indicates their position, the line is drawn in the sand.

A Rans S7 owner had a small fiberglass header tank made for him and before he even finished and flew the plane the ethanol had melted the resin and during his first running of the engine it coated his valve stems causing bent pushrods, valves hitting pistons, for about $10,000 repairs at Lockwood. That is pretty hard to take in our hobby.

Dale

I agree that this Service Newsletter is a CYA event but I do think the explanation for it was missing.
It seems that the problems with the fuel system contamination is a result of the ethanol separating from the gasoline and this can be caused by fuel being left for long periods of time in the fuel system and not being used. I don't know what this time period is but from what I've read it can have a lot to do with the temperature, humidity, and the length of time you leave your aircraft unused.
There is a lot of information available on the Matronics web site about it which can explain it better than I can.
As of today I have 400 hours on my aircraft with no problems at all and Ted Sutton has 750 hours on his and no problems.
I talked with Gary today and he said he uses auto fuel in his A/C and confirmed that the SB was a CYA letter.
Just cannot know how much us guys and gal fly our airplanes so the letter was the wisest thing to do.
To be on the safe side use your airplanes and if you'r going to park them for awhile take the fuel out and put it in your Ferraris.
And always, always,always, do a complete preflight.

We did not run ethanol but the original tanks that came with the plane fell apart. Fuel leaked into the wings and released the glue that held the fabric together and the bottom seams on the wings started to separate.

The plane has been down since June. We were given replacement (fiberglass) tanks but had to cut out the old tanks, put in the new ones and re-wrap the inner section of the wings and repaint. It isnt done yet as it was a task we were really not prepared for.

Anybody think about looking into getting a set of tanks roto-molded? Don't know how much it would cost, or what you would need to do to get it done, but I bet it would be a popular mod.

Hey, guys,

I'm about ready to install my tanks. Here's the situation. These are "original" from the kit sold in '03. Sounds like these and ethanol will produce an ungood result.
What are your opinions about using 100LL but with the TCP Treatment? It is a lead scavenger which converts the lead to lead phosphate which reduces fouling of the plugs. Effect on the oil? Not sure. Or, is this a great time to consider finding some aluminum tanks and hope the ethanol doesn't create any more problems than just with the tanks?

Dennis

Suppose this could be the reason for Just's recent letter....

This from EAA: FAA to STC Holders: No Ethanol in Auto Fuel


The FAA has issued a special airworthiness information bulletin (SAIB) warning aircraft owners and operators with auto fuel supplemental type certificates (STC) to ensure the fuel they use does not contain alcohol (ethanol or methanol). The SAIB reinforces EAA’s ongoing efforts to ensure the availability of compliant autogas by heading off or modifying legislative attempts in several states to require ethanol in all gasolines sold.

EAA, one of two primary sources of automobile gasoline STCs for general aviation aircraft, advocates that, at the very least, states should exempt premium grade fuel from ethanol mandates to ensure a readily available and safe fuel supply for aircraft.

The FAA cites numerous reasons alcohol and airplanes do not mix. Alcohol:

Adversely affects the volatility of auto gasoline, which could cause vapor lock.
Is corrosive and not compatible with rubber seals and other materials used in aircraft, which could lead to fuel system deterioration and malfunction.
Is subject to phase separation, which happens when the fuel cools as an aircraft climbs to higher altitudes. When the alcohol separates from the gasoline, it may carry water that has been held in solution and that cannot be handled by the sediment bowl.
Reduces the energy content of fuel. Methanol has approximately 55 percent of the energy content of gasoline, ethanol 73 percent. More alcohol equals reduced range.
EAA’s auto fuel STC has saved aircraft owners untold thousands of dollars by allowing them to use auto fuel rather than more expensive avgas. The FAA recommends that owners use automobile gasoline that conforms to the specifications published in their airplane flight manual or automobile gasoline STC flight manual supplement. Those unsure about the presence of alcohol can perform a simple test with EAA’s auto fuel Alcohol Test Kit.

dave

The only question about the TCP thing (just looked into this, not sure yet) is it contains toluene, naptha and isoprpanol (according to the company's website). Toluene and naptha are petroleum based solvents and isopropanol is an alcohol-solvent. I just have not figured out if it will cause more problems with the tank than it will solve. I am inclined to just run 100LL and deal with it's issues, since Maine is one of the states that has determined that being PC for Al Gore is more important that ALL of the problems with ethanol.

Based on a quote I just had done for a set
of parts at work, I would guess the mold to
have the tanks roto-molded would cost $15 to
$20 K. I suppose it could be shopped around
and possibly found cheaper. I have no idea
what that material would be for the molded
parts, or the cost per part to produce them.
The roto-molded process would probably be a
good fit for this application. I would think the
molder could use a tank to do a CMM study to
get the molded parts close to the fiberglass
tanks dimensions.
The molder I was talking to is near Toccoa.

I think this is a good idea, but it will take
a lot of effort to implement it.

John

New member/first post/Highlander builder wannabe...

I'm *very* close to placing my order (a few minor details to work out), and the tank issue prompted me to do some looking around for solutions/modifications before I pull the trigger -- comparing to Avid/Kitfox tanks, what those builders did, etc. Found this site:

http://wingtanks.com/

Ethanol-proof, polyethylene tanks for the Kitfox. I don't know anything about the company, or if they'll fit the Highlander (wing profile, rib bay size, chord). Perhaps one of the experienced builders could take a look and see what they think?

The "About Our Tanks" page even mentions/links to Just Aircraft...

Read "About our tanks" on that page, and it says that Just Aircraft has been using the tanks. Or just call them and ask.

Bob