Avgas LLC Unveiled

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In last weekís blog, I was bemoaning the fact that the FAAís avgas replacement effort had entered the dark phase and itís now impossible to find out much of anything about whatís going on behind closed doors. No one seemed to know anything about a company called Avgas LLC, which is one of five companies to have submitted fuel candidates.

The FAA was of no help and the PR office is now to the point that they donít bother to return queries.†Fortunately, the companyís principal, John Elling, contacted me last week. He gave me a general sketch of what they have in mind. Ellingís Avgas LLC is a tiny startup which is itself working with another startup called XF Technologies.

The company is developing a family of compounds called furoate esters for use as oxygenate blendstock in gasoline and diesel fuels. Think of them as an alternative or an enhancer for ethanol oxygenates and youíre in the ballpark. In fact, XF is pitching furoates as the next generation oxygenate. XF hopes to produce these compounds from cellulosic biomass sources. Elling told me furoate esters have good octane characteristics (and arenít a cetane depressant for diesel), are non-corrosive, hydrophobic and have good lubricity. In short, they look attractive as fuel additives.

XF has in mind producing its furoates from waste biomass using the kind of cellulosic processes that a number of companies are working at perfecting. And therein lies the snag. Although they pencil out well and potentially have attractive economics,†cellulosic processes havenít proven out yet in the real world, at least in terms of efficient production. They may get there, but they arenít quite ready to take on petrochemically produced additives or even traditional fermented ethanol which, as we all know, has its own problems.

Then thereís the question of what the base blendstock would be. Would it be traditional aviation alkylate, which starts with an octane rating in the low to mid 90s? Or would it be a conventional automotive premium blendstock? Elling says the company hasnít gotten that far yet. I sense that there's an assumption that whatever replaces leaded avgas will use aviation alkylate as the base blendstock. Thereís such a deep seated bias against motor gasolines for aviation use that I donít see them even getting any kind of serious consideration in the emerging PAFI process, no matter who proposes them. The non-alkylate exception is Swift Fuel, which is a binary composed of mesitylene and isopentane catalyzed from acetone. The acetone could source from biomass, too, but may be more likely to come from natural gas or traditional petrochemical sources.

To be blunt about it, itís difficult for me to see how fuels like this will make it through the first cut of the FAAís PAFI process. And sorry to say that probably applies to Swift Fuel, too. I just donít see how the mechanism the FAA and the industry has set up would be sensitive to innovation, even if it meant a 25 percent reduction in price. In fact, the PAFI structure seems likely to be completely insensitive to price; it appears structured to obtain a workable fuel with the fewest unknowns and easiest transition into the field. That may not be ideal, but it's not a crazy idea, either. And even though the FAA denies itís picking winners and losers, thatís exactly what itís doing, since itís applying P&L considerations to the selection process. Depending on how thatís weighted in the final decision, it wouldnít be unreasonable to believe that Shell and the consortium of BP, Total and Hjelmco have the inside track. Especially since ConocoPhillips, Exxon and Chevron arenít even in the game.

Too bad this PAFI thing isnít going on five years from now. By then, cellulosic technology may come into its ownóor sink in the tryingóand a truly innovative aviation fuel would have a chance. As it is now, whatever emerges will probably be the fuel that propels the industry into the smoking crater it seems headed for. Gotta hand it to GA; we're really good at finding objections to potentially less expensive solutions in the name of safety, regulatory inertia and good old (expensive) tradition.

Asiana/777 Follow

When I was talking to my friend, NTSB investigator Bill English, about the Asiana accident investigation, I was kidding him about having too few accidents to investigate. I boldly predicted he might just be able to coast into retirement with no more big accidents to handle.

A text I got from him on Thursday dispelled that notion. He was on his way to Ukraine to provide U.S. participation in the shootdown of MH 17. No oneís really sure what kind of a role the U.S. will have in the actual kicking of tin, although it clearly has a major role in whatís likely to be an intelligence-based crash investigation. Canít call it an accident, obviously. Mass murder would be more appropriate.

In any case, Bill was supposed to be at AirVenture next week to speak about Asiana. As of Sunday, those plans are uncertain. Iíll keep you posted.

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Comments (19)

Cellulosic ethanol is a biofuel produced from wood, grasses, or the inedible parts of plants. Been around for a while. The cost, the cost.

Posted by: Rafael Sierra | July 20, 2014 2:14 PM    Report this comment

With GAMI working on getting their fuel approved through the STC process, is there any chance some other 100LL replacement fuel could also be approved one way or another besides (or in addition to) whichever one is approved through PAFI? I can't imagine in the long term that a multi-fuel solution (beyond JetA and 100LL/whatever) would work, since it's hard enough to find mogas, but perhaps in the short term we might still be able to have the market work out a viable alternative fuel for the long-term solution.

Posted by: Gary Baluha | July 21, 2014 8:48 AM    Report this comment


Although there might be ample incentive to obtain STCs to cover the minority of the vehicle types that are responsible for consuming the vast majority of the 100LL sold today, any fuel that is not approved as a direct replacement for 100/130 and 100LL in ALL legacy engine/airframe combinations would be of no use to the majority of vehicles in the GA fleet. That's not a "replacement" fuel - it's a substitute fuel for a deserving fortunate few. Further, regardless of the method of approval, any replacement fuels must be fungible with 100LL - same densities (mass/volume and energy/mass) and full miscibility, in-ground and on-wing.

My reading of the PAFI slide deck leads me to conclude that universality and fungibility are NOT requirements - they're simply on the FAA's "nice to have" list. IMWO, that's a fatal flaw. Essentially, we're all screwed before the process even has begun. All in the name of the religion of any-leaded-fuel-is-unacceptable. I suppose lead-acid batteries, bullets, and fish-lure sinkers are next. And let's not forget lead roof flashing, which obviously is responsible for the discharge of toxic pollution into storm sewers everywhere. Brought to us by the same geniuses who spawned the MTBE debacle.

This government already turned my perfectly good Loran navigator into an expensive paperweight. As far as I'm concerned, it this government wants to turn my engine into another paperweight, it can purchase and install a new-fuel engine in my airframe - at its own cost.

Posted by: Tom Yarsley | July 21, 2014 2:35 PM    Report this comment

On MH17; "Can't call it an accident, obviously. Mass murder would be more appropriate." I agree.

Posted by: Rafael Sierra | July 22, 2014 9:08 AM    Report this comment

While there is certainly a deep-seated bias against ethanol-free auto gas (mogas), we should be involved in SERIOUS dialogue to analyze, and probably dispel, the negative aura surrounding this approach. Like the pilot's Third Class Medical Certificate, there is an awful lot of smoke surrounding this fuel and not a lot of hard negative data. I've been "treated" to a lot of seemingly uninformed opinions on the subject by a lot of "experienced" aviation experts who have little or no experience with mogas. Well folks, there a lot of us out here who have been using it under STC's on appropriate compression aircraft engines for a LONG time who are very satisfied with the result. Read that, lack negative results from our perspective. In the third world, it is settled fact. I have seen very little or no DOCUMENTED negative data from the nay sayers. It's time to put up or shut up. This makes so much sense for the vast majority of piston aircraft engines that it is blindingly obvious, even with minor modifications such as water in higher compression engines. Way too much money is being wasted on expensive "weird science" solutions that have little or no prospect of financial success when the lead pipe cinch solution is staring us in the face.

Posted by: George Rodrigues | July 22, 2014 9:43 AM    Report this comment

I used mogas for a number of years in the 80's when it was somewhat predictable under a Peterson STC. But the problem with mogas is you never know what you are getting, even after you ascertain there is no alcohol and especially today with all the seasonal shifts in composition. I switched back to using avgas simply because I could be trust what I was flying. My understanding is that European mogas is controlled the much better the way avgas is here in the US.

Posted by: A Richie | July 22, 2014 11:11 AM    Report this comment


I'd hardly characterize a water injection system as a "minor modification."

Posted by: Tom Yarsley | July 22, 2014 3:40 PM    Report this comment

Not to nit pick, I'm calling water injection a minor modification in the global sense, not the official FAA definition. I characterize it as minor in cost, documentation, time, and actual modification of those aircraft which would need it. A thundering plurality of older piston engines DON'T need the water injection! But the overall cost of some new fuel as a plug in to 100LL avgas? We're dreaming if we think that won't be a WHOPPING increase at the pump over already expensive 100LL. And that assumes that someone actually pushes the ball over the goal line and makes it widely available. Hmmm, mogas is already several dollars a gallon CHEAPER in most locations. Current increased (one time initial) cost of the mogas switch is mostly associated with the cost of the STC and plus your distribution solution. If the global approval of mogas in appropriate engines occurs, the distribution cost component SHOULD go away quickly (doesn't mean it will, aviation business practices being what they have been for a long time). The switch to mogas pays for itself rather quickly, do the math...

The alcohol problem is real, but is almost, but not quite trivial, to solve. It's this simple. TEST ANY MOGAS YOU PUT IN YOUR AIRCRAFT FOR ALCOHOL!!! The test is so simple and depends on the rock solid principle of water-alcohol miscibility (total solubility in each other). Put 9 parts of mogas into 1 part of water in narrow vertically graduated glass contain and shake vigorously. The mixture should separate rapidly and completely into the original two phases, 9 parts fuel to 1 part water. If the fraction of water increases, say 8 parts fuel to 2 parts aqueous phase, you got some ethanol in your mogas, partner. There are other tests, but this one is the simplest.

I don't mean to trivialize the problem of availability today, but it is a POLITICAL problem stemming from the shell game they are playing to try to politically force favorable economics on "biofuels". It appears to be an expensive failure, but the patient hasn't quite realized he's dead and the doctor doesn't want to explain the death because it is so expensive. I do believe that if the FAA and the general aviation community teams up with Senate and Congressional aviation caucuses to legally mandate the availability of ethanol-free mogas for aviation use, the great majority of our piston engine GA aircraft will be able to use alone or in conjunction with other changes, such as water injection or minor derating, mogas at an astonishing savings over the development/deployment cost of alternate fuels we now see or will see for the forseeable future. The technology to separately provide an adequate stream of adequate mogas is pretty simple and already exists.

A. Richie, would you share with us your negative experience after the 1980's with us? Testing for ethanol is a minor pain, having to have and maintain you own tankage is manageable and not too expensive, and in some states, I understand that currently finding ethanol-free mogas may be illegal by state law. What else? Most importantly, did you have performance issues. I live in South Carolina and have flow mogas from there to Oklahoma, and in 100 degree summers on the ground and subzero temperatures at altitude. What else we got? Now that was a friendly inquiry, not a call out. I'd like to have folks with REAL data, not opinions, input to this, positive AND negative.

Posted by: George Rodrigues | July 22, 2014 9:48 PM    Report this comment

The Air Plains Inpulse ADI system costs around $12,000 installed. It's not a huge mod to the airplane. Requires a tank in the baggage area and the associated plumbing running up to an injector plate in the engine. It injects water into the induction, not into each cylinder.

You have to fly a lot to make it worth the investment.

Posted by: Paul Bertorelli | July 23, 2014 5:56 AM    Report this comment

Whether the cost of water injection is major or minor in the global sense or the FAA non-sense, my concern would be the cost to me. For $12,000 I get no improvement in performance, higher empty weight, less useful load, less range, more complexity, new potential failure modes, maintenance issues, STC compatibility issues... in other words a less useful airplane.

Posted by: Richard Montague | July 23, 2014 7:51 AM    Report this comment

George, I don't have any scientific data to share with you. I never had any performance problems with mogas. All I can say is that the original STC conformed to an ASTM spec that I'm told is not very common today in the fuel universe (but I could be wrong about that). At first I was comfortable with it when virtually all mogas conformed. Then they started adding MTBE, then they removed it, then ethanol was added, also various "cleaners" (Techron, etc). depending on who sources the mogas. Then on top of that, there are seasonal mix variations required by the EPA. Mogas has a shorter shelf life than Avgas that sometimes can be an issue during extended maintenance down times or over the winter. And then my engine rebuilder says he can tell the moment he pulls a cylinder if mogas had been used in an engine; and he wasn't real excited about it. Avgas 100LL has been the same since it came out in the 70s. I remember green 130 and purple 145 were available before that as well as 80/87. The point is that these fuels are controlled spec for aviation use where your butt is on the line. Get mogas under spec control (like I'm told it is in Europe) and I'll gladly use it instead. Unfortunately, the politicians now want to play fuel chemist with our avgas now like they did with mogas. Can't they just stick to their speeches and photo-ops and leave us alone?

Don't get me wrong, I am a fan of mogas if it can be controlled and consistent. But the way it is managed today in the US I'm just uncomfortable flying it, especially when trying to clear that tree line at the end of the strip. Good luck with the mogas campaign, I'm pullin' for ya...

Posted by: A Richie | July 23, 2014 8:39 AM    Report this comment

Good topic - good exchange of knowledge. I'm learning here, thanks guys.

Posted by: Rafael Sierra | July 23, 2014 9:59 AM    Report this comment

That was a good and useful treatise A. Richie. Thank you.

It would be interesting to hear from the engine rebuilder how he knows that mogas has been used.

Posted by: STEPHEN EGOLF | July 23, 2014 10:56 AM    Report this comment


How does the Air Plains ADI system deal with ice? I know that our on-board water tanks (the water jugs in the survival kit) ice over in October, and don't thaw out until April.

Posted by: Tom Yarsley | July 23, 2014 11:57 AM    Report this comment

Steve, as I recall (this was about 16 plus yrs ago) it seemed to me it may have been the smell or discoloration of the parts, but I don't really know if there were any mechanical issues that were present. He has since gone out of business and I have lost contact with him. There may be other engine experts that could tell you; if you find out, let us know!

Actually, to honestly determine whether anything detrimental had occurred you would need an full-blown engineering study done by a professional powerplant engineer. Most of those guys work for the engine producers, but they can't contradict the company line, so it's difficult to get the real unbiased scoop. I wouldn't even trust an engine builder completely, even though he may have an eye (or nose) for spotting it he probably isn't qualified to make that determination. My personal (uneducated) opinion is that it's probably insignificant differences if any, but that opinion is worth exactly what you paid for it!

Posted by: A Richie | July 23, 2014 7:47 PM    Report this comment

Yars, the ADI fluid is 60 percent methanol, 40 percent water, so it has a very low freeze point. Induction ice isn't an issue because the injection happens downstream of the carb. In addition to freeze protection, the methanol adds a little energy to the combustion while also cooling the charge,

As for the negatives for ADI, everyone has listed them. But you've ignore the positives--up to $20 an hour in reduced fuel costs. That's not trivial. But you have to fly a lot to make the investment worth it. Most owners do not. Then again, most owners can already burn mogas without need for ADI.

But they don't. In droves. The biases are completely unsupported by fact. I have them, too, and I think I understand the issues. I could burn mogas in the Cub, but I don't.

Posted by: Paul Bertorelli | July 23, 2014 9:07 PM    Report this comment

I would run mogas in my plane, but the problem is that ethanol-free fuel just isn't available in the areas I fly. As a result, I can't justify the cost of the STC.

Posted by: Gary Baluha | July 24, 2014 9:51 AM    Report this comment

A significant problem is availability. In California there are five locations where Mogas is dispense and at about the same price as Avgas. This would improve as demand increases.

Posted by: Rafael Sierra | July 26, 2014 2:28 PM    Report this comment

Regarding mogas in 80-octane engines: I put something over 40,000 gallons of the cheapest-available regular grade mogas through my C-182, mostly during a 15-year period of airborne commuting to & from work. Hypothetically speaking there MIGHT also have been ethanol in it during the later years of that era, although that of course would not have been covered by the STC.

Two engines were involved and both ran 2400+hours, well beyond their 1700-hour TBOs, without cylinder changes or any other problems. Had I not moved up to a 100-octane bird I would still be burning auto fuel.

So as you might guess, I have little respect for the opinions of the "you're gonna die if you use mogas" crowd of so-called experts.

Posted by: John Wilson | July 29, 2014 11:52 PM    Report this comment

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