What If They Had A PAFI And No One Came?

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Swift Fuel’s announcement that it’s bailing out of the FAA’s troubled Piston Aviation Fuels Initiative had an inevitability about it. Following the FAA’s announcement in June that it was suspending work on finding suitable unleaded replacements for 100LL, a not-that-subtle whiff of a certain metaphor related to chairs on the deck of a doomed ocean liner was detectable.

Without saying exactly that in its press release, Swift says it’s abandoning PAFI’s contorted path in favor of the same STC process already underway by General Aviation Modifications Inc. and, more recently, Phillips 66 partnered with Afton Chemical. Swift used the term “alternative pathway,” which, as far as I know, can only be an STC.

And then there was one. That would be Shell, who, along with Swift, had one of the two fuels perking through the PAFI process. Shell’s intentions are unknown, but based on Paul Millner’s reporting in this blog, the company doesn’t appear to be particularly impressed that lead is that bad. I won’t be the slightest bit surprised if they take a powder on PAFI and abandon the unleaded avgas effort entirely.

Fiasco doesn’t do justice to describing any of this. PAFI emerged because the industry—airframers, engine manufacturers, refiners—reasonably believed nothing would move off the dime until the FAA brought the various parts and pieces together in some kind of project that would yield a publishable standard for unleaded avgas similar to the ASTM D910 doc that has served leaded fuel so well. The FAA imprimatur was seen as must-have. It may turn out to be the poison pill, by the looks of it, or least the process is.

It appears to have run off the rails because all of the fuel companies—and especially Shell and Swift—came at the problem with unique chemical solutions that delivered the required 100 octane, all right, but were too different from 100LL to serve as the vaunted drop-in replacement. It’s different for conventional avgas because although one refiner’s alkylate may be a little better than the other’s, it’s chemically the same stuff. And tetraethyl lead is tetraethyl lead; use a little more or a little less to gin up the octane.

At AirVenture last year, the FAA admitted that each of the two fuels would cover a portion of the piston fleet, but neither would adequately cover all of it. And as Millner reported, non-linearities were noted when the fuels were intermixed with each other and with 100LL. Why this wasn’t foreseen as a cautionary for PAFI is puzzling, since the 50-cent tour of any refinery—or a high school chem lab—would suggest as much.

To further stymy PAFI’s potential for success, once the fuels entered the process, they couldn’t be tweaked or reformulated to address whatever shortcomings the very testing was supposed to reveal. My admittedly imperfect understanding of this is that it had to do with proprietary concerns and government vendor rules. But as GAMI’s George Braly pointed out, this defies the basis of research, which requires testing, fixing and retesting in a relentless intellectual pursuit of solving the problem at hand.

So now what? Will Shell re-enter the stalled PAFI process? And if so, can it address whatever shortcomings its fuel happens to have? If so, bully. It might own the market, land a workable ASTM standard and make a mint selling the stuff—or licenses—worldwide. I don’t think this is answerable right now.

Otherwise, welcome to the Balkanization of avgas. GAMI, Swift and Phillips are all pursuing discrete STCs. It’s unlikely all three of those fuels will meet the same standard, or maybe any standard, so if the STCs are approved, how is this supposed to work? Does one airport have Swift, another GAMI and yet another Phillips? And if so, can I intermix them and who’s going to warrant that this can be done safely. (Hint: It’s not going to be PAFI.)

Perhaps the STC applicants should add to their already burdened plate miscibility testing. But how do you do that until the other guy’s STC is approved? It gives me a headache trying to imagine an FAA bureaucrat with the guts to sign off on the testing program for that.

Don’t let it escape notice that Swift chose not to go quietly into that good night by withdrawing from PAFI, but issued a deliberate press release distancing itself from the PAFI rubble. I think it needs to do that to declare that it’s still in the game, but now on its own terms.

As Millner mentioned earlier this month, there are significant vulnerabilities here. Just because the current EPA has suspended the finding of endangerment against tetraethyl lead, that’s no guarantee it won’t re-emerge later, either by administrative fiat or court order. If GA settles back into its comfortable embrace of lead, we may have no ready replacement when the effort to ban it finally gets teeth. And there's Europe and perhaps Asia to think of. Both have their own concerns about leaded fuel.

In the smoke curling up from PAFI is this cheery thought: Those who thought the FAA was engaged in picking winners and losers via PAFI can take comfort from the notion that now the free market, not regulators, will have to sort this out. Maybe it was wrong to think the only way to solve this seemingly intractable problem was to have the FAA oversee it and jolly it along. We can all plainly see where that got us.

Comments (21)

This fiasco is exactly why I do not support either candidate that have been submitted for the new FAA adminstrator. The president's candidate does not have much recent GA experience and the current acting adminstrator is just another bureaucrat who is part of the existing FAA bureaucracy. We need someone who can get this issue resolved before the courts or worse the EPA does it for us. Someone who understands the GA situation in reguards to this unleaded fuel issue. If the FAA drops the ball on this and lets the EPA do it for us this might add another nail in the preverbal GA coffin.

Posted by: matthew wagner | August 29, 2018 8:25 PM    Report this comment

I don't know what the end result of all this will be, but I'll be sure to only buy aircraft and engines that can run existing unleaded. That way I won't be stranded crying for 100LL when it inevitably disappears.

Posted by: Cameron Garner | August 30, 2018 12:57 AM    Report this comment

It's sufficient for me to say that it's complicated.

Posted by: Rafael Sierra | August 30, 2018 1:45 AM    Report this comment


I'm not at all surprised to see Swift bow out. They began life as a biotechnology company shopping microbial technology that might be used to produce aviation fuel. The economics were rarely discussed. During the clean energy boom eight years ago they (and other marginal concepts) were able to find financing and government grants. When that ended, Swift reinvented itself as a petrochemical company and got itself selected by the FAA - an agency that is not known for, and shouldn't be expected to possess, chemical engineering expertise.

I'd like to make a couple of comments about mixing these candidate fuels. If you don't like chemistry, stop reading and I won't be offended. Each fuel has a fairly unique set of chemical components and, when mixed, the properties (vapor pressure, relative volatility, tolerance for water, detonation resistance.....) of the resulting solution can be very different from either starting fuel. Furthermore, these do not change in linear proportion as the fuels are mixed. Mapping these effects It is a daunting problem and an area of considerable research in chemical thermodynamics.

I think we are underestimating the difficulty of certifying multiple fuels in all combinations. It is entirely possible that the STC process will be more effective when it is directed toward modifying existing power plants to tolerate current unleaded fuels.

The market will sort it out. For the time being I'm in total agreement with Cameron.

Posted by: kim hunter | August 30, 2018 2:20 AM    Report this comment

NOW can we get ethanol-free mogas at airports, please?

Posted by: Thomas Boyle | August 30, 2018 6:50 AM    Report this comment

If you look at back issues of flying and other aviation magazines you find this debate about unleaded avgas has been going on for decades, since the 80's at least. I have a 2014 dodge. It can run on anything from 87 to 93 octane with no problem and adjusts the timing to prevent preignition. We are looking at this from the wrong end. If you want unleaded fuel you need to update the engines and ignition systems. We are still using systems designed in the 1950s. The FAA needs to certify drop in electronic ignition systems for current engines which, with variable timing, would allow the engines to operate on a variety of octane levels with minimal performance loss and reduce engine problems such as stuck valves and other issues due to lead. Our problem isn't so much the antiquated rules of the FAA regarding fuels but the antiquated rules requiring us to use ancient technology when so much more is available.

Posted by: RODNEY HALL | August 30, 2018 7:28 AM    Report this comment

Although it can be argued (persuasively) that this is a political problem, we should acknowledge this possibility:
There may be NO chemistry that solves this problem. None.

Goodbye, high-compression engines - and the legacy airplanes that are bolted to them. Hello, new engines - likely bolted to new airplanes that few of us old hands can afford, or would purchase even if we could.

As things now stand, the prospective outlawing of leaded aviation fuel could be a near-extinction-level event for piston GA.

Screw all of this. My next airplane will burn kerosene.

Posted by: YARS (Tom Yarsley) | August 30, 2018 7:28 AM    Report this comment

This PAFI process fiasco is a perfect example of an FAA 'leadership' (oxymoron) run amuck. Even with GPS', roadmaps and explicit acquisition and contract rules, they can't figure how to find success. If you're talking about metaphors and deck chairs ... try this ... lead, follow or get the hell out of our way, bureaucrats!

In much the same way as the FAR Part 23 rewrite turned out to be nothing more than a path for others to start using STC's to meet the goals rather than with a true rewrite, the PAFI goal is likewise headed the same way. Sorry, but I don't see that -- or this -- as progress at all ... just a long and circuitous alternate path to reach a semblance of doing something. Success (or doing their job) it ain't.

I think that they're afraid to commit to a hard and fast standard where 'they' could later be faulted. So the easy path is to let others come to 'them' with STC's. That's pretty much what they did with LSA, too, now that I think about it. They get the monkeys off of their back, make it seem like they've done something and go on to pat themselves on their back ... now devoid of monkeys. I see a closed loop pattern here. The only hard decisions I see involve ruining small companies that ARE trying to do something. SIGH!

It's no wonder Swift threw in the towel. Kudos that they'll now try the STC route. Meanwhile, hundreds of thousands of humans are dying because of the minute amount of lead being spewed from the piston driven engines of all those rich boys with private airplanes gallivanting around.

Matthew, I hereby volunteer to accept the position of Administrator. Let's Make GA Great Again !!

OH ... and I kept the original 80/87 engine from my C172 for exactly the reasons expressed here.

Posted by: Larry Stencel | August 30, 2018 9:37 AM    Report this comment

"...welcome to the Balkanization of avgas"

Great line, Paul, exactly what I have been thinking.

Posted by: A Richie | August 30, 2018 9:37 AM    Report this comment

I completely agree with Rodney Hall. The FAA doesn't understand the problem, let alone the solution.
Once again, they are trying to lead us down the rabbit hole of government bureaucracy.

Posted by: April Talmadge | August 30, 2018 9:41 AM    Report this comment

80-85% of the GA fleet already runs fine on non-ethanol; mogas. My old Bo's E-228-8 runs fine mixed with leaded 100LL or running on pure mogas.

My dry sump E-225-8 will drop in fine on a new SR-20 and give a 25hp boost at take-off as a bonus. Probably slick up the cowl a bit since Cirrus would have options to locate the oil tank in a more aerodynamic location.

Since we can't get modern fuel/ignition/timing technology introduced to new production GA engines, we can install old technology into new air-frames, monitor them with new digital technology allowing for GTN650/750 displays for 70 year old engine performance. EI and JPI have figured that out long ago.

See, problem solved. EPA happy, Chinese owned Cirrus gets to build 70 year old Chinese owned Continentals, maybe produced in Alabama ( their happy and Alabama happy), Trump gets credit for more jobs ( he is happy), US GA consumer gets to fly at $2.50 per gallon fuel available all over the US (well almost all over the US unless you are based in the corn-belt) so large portion is happy, and the fuel distribution for all this has been in place for over 50 years ( that makes the refiners happy especially those who are producing 100LL and ethanol free auto fuel ( I can see Shell being happy). Look at all the happiness this solution would produce.

Plus, I and a bunch of other owner/pilots would be even happier than the happy folks at Cirrus, Continental, and Alabama ( and the White House) as we see the value of our old airplanes appreciate.

Once again, I can hear the Vref for my old Bonanza ticking another notch upward as PAFI implodes.

Long live unleaded, non-ethanol auto-fuel. Long live old, low compression, magneto equipped airplane engines.

Now, if I can only talk Hartzel, McCauley, or MT to come up with a drop in replacement for my Beech , no AD, electric prop, I would be in tall cotton. And then even happier than I am now.

Posted by: Jim Holdeman | August 30, 2018 10:01 AM    Report this comment

Anyone who reads John Deakin (AKA "Pelican's Perch") would know that the PAFI process was pretty well doomed from the start. Deakin opines that a drop in 100 UL is unlikely, given the other restrictions from OSHA and EPA on toxicity of available high-octane hydrocarbons. You can either have octane or low toxicity, but you can't have both. What I find amazing is that the FAA apparently has no one who understands (or cares) about how developmental studies are conducted. To enter into a process to "refine" the formulation of a fuel and not allow any changes to the original mixture is unthinkable. A freshman chemistry student knows better than that.

For once, however, the little guys get a break on this mess. Older low octane engines can do just fine on either ethanol free mogas or the (approximately) 94 octane avgas that is left after the lead is removed from 100LL. The big-bore high HP engines will have to have modifications to accept the same. But, their owners are better able to afford the costs than the unwashed masses. The alternative is to hope that GAMI or another STC applicant can come up with a universal substitute that may have its own problems, especially if the compatibility with other fuels cannot be overcome.

Oh, and with all due respect to those who worship the kerosene gods, diesel engines are probably not the answer. While they may work in new airframes, they are hideously expensive, complex and not field repairable. Squeezing them into the legacy fleet is not an option and the whole idea of a replacement fuel is to keep the legacy fleet flying. Electronic ignition with variable timing is a much better, and more cost effective solution. Plus, it actually gives some return on investment through better fuel economy, longer plug life and lower maintenance costs. As usual, the free market can probably develop an answer if the FAA will just get out of the way.

Posted by: John McNamee | August 30, 2018 3:49 PM    Report this comment

Agree with the emerging common thread here - the solution will ultimately be in the engine, not the fuel pump (the big one on the ground with the long hose attached to it!).
There are solutions -existing or proposed- out there already, from water injection to electronic ignition. Many of these 'solutions' can already be found flying in experimental aviation, so it isn't like they are untested and unproven, just not certified.
Of course, owners of aircraft with engines that presently require 100LL will cry foul at having to pay to update their aircraft, but the alternative appears to be high-octane purgatory.
Plus, a simpler fuel network (avoiding that balkanization) of good UL fuels is good for everyone EXCEPT that 100LL dependants.
I don't see diesels being the solution. Plenty of companies have been claiming their new diesel engine will revolutionize the industry for years... and we are still waiting. Sure, there are exceptions, such as the Diamonds, but there are too many negatives balancing the positives to expect diesels to ever dominate.

Posted by: Cameron Garner | August 31, 2018 12:56 AM    Report this comment

"Of course, owners of aircraft with engines that presently require 100LL will cry foul at having to pay to update their aircraft..."
You're almost right. Just substitute "replace" for "update," and you'll have it pretty much nailed.
Anybody who believes that every existing certified combination of airframe and engine will find a ready-to-install engine-upgrade STC under their Christmas tree simply hasn't been paying attention.

At this point, the best we can hope for is another exercise in goalpost-moving - like dropping the requirement for miscibility, for example.

Question: How would average Americans react, if the government outlawed gasoline? "Starting tomorrow, you've gotta burn pure ethanol." Exactly.

Posted by: YARS (Tom Yarsley) | August 31, 2018 9:43 AM    Report this comment

Bravo YARS.

Sooo, it is sufficient to say that the fix is technically intricate, expensive and unnecessary.

Posted by: Rafael Sierra | August 31, 2018 10:09 AM    Report this comment

Typical government approach trying to dictate the One Solution instead of letting the market find a way.

I say we jettison the FAA's light aircraft division and hand that over to the EAA or something. I suspect most certified aircraft owners don't see much value in FAA certification once the airplane is delivered...

Posted by: Robert Gatlin-Martin | August 31, 2018 11:21 AM    Report this comment

I think I'd approach it from the oppostie side. Lock all the competitors in a room and don't let them out until we have a 100 no lead standard (i.e. product) that'll transition away from 100LL and work in all our engines. It appears to me it's a winner take all right now. If a common standard is established and corporate investment can be salvaged via some consortium maybe we can make everyone happy.

The FAA has their hands' tied with bureaucratic rules and proprietary submittals. Yes, they were put in a nearly impossible position from the beginning. Industry can solve this if they cooperate. (IMHO)

Posted by: Robert Mahoney | August 31, 2018 12:55 PM    Report this comment


You are right in one respect. It is possible to manufacture a fuel that will meet the requirements of all engines under all conditions. Swift would have achieved it with their biologically synthesized product given time. The problem is the manufacturing cost of creating a synthetic fuel versus refining and blending existing petroleum fractions. So far, the only semi-synthetic fuels with favorable economics are pure ethanol and ethanol-refined petroleum mixtures. It's important to remember that these fuels are marginally effective and were developed at a cost of billions of dollars by governments world wide (US, Canada, Brazil....).

Posted by: kim hunter | August 31, 2018 4:13 PM    Report this comment


A small clarification for you: ConocoPhillips and Phillips 66 are separate unaffiliated companies since 2012. Phillips 66 is pursuing the STC with Afton.

Posted by: Geoff Reid | August 31, 2018 4:53 PM    Report this comment

They should keep the present ASTM D910 formulation, and work instead on a point-of-use delivery system for the TEL. Then, most aircraft could operate on the unleaded, while the lead is available for introduction at the time of fueling for those that need it.

Posted by: michael werner | September 1, 2018 12:52 AM    Report this comment

You're right, Geoff. Thanks.

Posted by: Paul Bertorelli | September 1, 2018 4:13 AM    Report this comment

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