Is Shell's Replacement Fuel Coming Up Short?

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There are two ways to look at the ongoing FAA fuels testing project called the Piston Aviation Fuels Initiative. One is that no news is good news and things must be perking along as planned. The other is that no news is bad news and that things aren’t going as planned or else we would have heard progress reports.

The rational among us would assume the former, realizing as we do that the federal rules on which the PAFI program is based require confidentiality to protect the proprietary interests of the companies doing the work. That’s not an unreasonable requirement given that the FAA is intimately involved in this process and necessarily intersects with the secrets companies doing the work would just as well keep secret until these fuels are finally approved.

But we live in a leaky world and what’s leaking out is not encouraging, especially with regard to Shell’s proposed unleaded replacement for 100LL. Recall that PAFI started in 2013 with 17 potential fuels from six entities. As PAFI has proceeded through its planned phases, that has been winnowed to two fuels for final testing, one from Shell and one from Swift. Both are now undergoing advanced testing, including flight trials toward a 2018 certification date.

The last official update from the FAA was in July at AirVenture, which delivered bland assurances that everything is just fine. From what I’m hearing, it may not be. Over the weekend, we heard from the fourth source who told us that the Shell fuel may have high toxicity and significant materials compatibility issues. One source told us the fuel is capable of stripping paint off wing surfaces and did. Two others told us the fuel has compatibility issues with seals and O-rings, a key element in the ability to drop into the existing fuel infrastructure, not the least of which is the fuel system in individual aircraft. We’re also hearing that it requires respirators and protective gear to handle, at least in the version being tested now.

Whenever a planned product overhangs the market with distant promises, whisper campaigns are inevitable. I’d say this is another one of those, except the sources I spoke to about it are highly reliable. No one wants to or can go on the record because of non-disclosure agreements and the aforementioned federal rules. However necessary such secrecy may be, it begets certain people lifting up the corner of the tent and that’s where we are.

I reached out to Shell about this and got what I expected: an assurance that Shell will deliver a fieldable fuel by the agreed-upon date in 2018. But a polite refusal to answer detailed questions about results of materials compatibility or toxicity testing. Both of these are critical because if the fuel that emerges requires HAZMAT handling at the dispensing point, that’s not just a non-drop-in, it’s worse than 100LL and of doubtful appeal in the market. For what it’s worth, we haven’t heard these complaints about Swift’s candidate fuel.

So what does all this mean? Ever the sunny optimist, I still believe there will be a viable replacement for 100LL and by 2018. The volume of business, although in graceful decline, still represents too much money to just walk away from. Something will emerge. I do have concerns that the materials compatibility will be devised in a way intelligent enough to represent every airplane, including my 78-year-old Cub.

And for the record, I’m not the only guy who has heard about this. I’m told by firsthand sources that the alphabets are well aware of it and so are people in the fuel community. (AOPA declined comment.) What I’d wish for is an honest, detailed update from the FAA and from Shell. If these problems have been addressed, say. Otherwise, if we’re headed for a train wreck here, better to find out sooner than later.  

The foregoing blog is opinion and commentary based on disclosed fact. AVweb welcomes alternate points of view, including guest blogs. 

Comments (16)

Paul, you are the eternal optimist. I truly believe that we will not get a drop in replacement as promised but something that will cost owners a Caravan full of one hundred dollar bills to implement. My take is that on some date future, 100LL will, by mandate, just go away. On that day FAA XXNL will be come the only replacement. Each aircraft will have some sort of mandatory modification or AD required to be able to use the fuel or be deemed not airworthy. The EPA will jump for joy, the greenies and tree huggers will be doing high fives and most of GA will be grounded or financially punished.

Remember this whole program is being run by the not so friendly folks in DC. Sort of like the MTBE and Ethanol debacles that have been stuffed down our throats for auto gas. The majority of Americans have been affected with lower fuel economy, corrosive and expensive auto gasoline all courtesy of the DC idiots They did it to tens of millions of us and we were not able to stop them. The voices of several hundred thousand aircraft owners and operators will not be heard.

As for your beautiful aged Cub, it will make a nice display hanging from the rafters of some shopping mall or you could do the "conversion" at considerable expense. Perhaps you could run auto gas if you can find any without ethanol.

Don't think this could happen? Consider the big bore Continental cylinder AD. The data does not support it, the alphabet soup agencies oppose it, NTSB opposes it. if you are unlucky enough to "win" the AD lotto, hang on to your wallet and replace those perfectly good cylinders. Why? Because some faceless and unaccountable brain dead bureaucrat slithering around in the bowels of the FAA says you must.

The caveat "past performance is no indicator of future performance" may apply, however, when dealing with the DC bureaucrats past performance almost always is a good indicator of future performance. I am afraid that once again the GA community is going to take it in the wallet on this one. Hope that I am wrong and saner heads prevail.

Posted by: Leo LeBoeuf | October 30, 2016 6:58 PM    Report this comment

Has GAMI's fuel gone anywhere? I know they were staying away from the PAFI process, and seemed like they had an alternate route that they believed in. If there's any group of people who I would rely on to deliver a *practical* solution, it's them.

Posted by: Joshua Levinson | October 30, 2016 10:02 PM    Report this comment

I hope that all of this works out well. But as my Irish grandmother used to say, "If wishes were horses, beggars would ride." My next airplane will burn kerosene.

Posted by: Tom Yarsley | October 31, 2016 5:48 AM    Report this comment

This is great news for O-ring manufacturers, hose makers and A&P's who need more work. And, imagine the fines if you let one drop of the stuff fall on the ground in the fuel pit. EPA will likely have a camera in every one; the fuel receipt can have the self-disclosure form pre-printed on it. (You know, the kinder, gentler FAA where you self-disclose and they slap your hand because you didn't argue with 'em?) For me -- personally -- my 172 needs a strip job anyhow so ... maybe I can find a way to "accidentally" spill some.

I guess all we can do is hope that the new replacement has the toxicity and cost of water and the heat value of nitromethane. If not ...

... one more nail in the coffin.

Posted by: Larry Stencel | October 31, 2016 6:53 AM    Report this comment

Seems to me that the toxicity of one drop-in 100LL substitute, might be due to aromatic content. Benzene (C6H6, the "mother" of aromatic hydrocarbons) is toxic and carcinogenic. Its derivatives aren't good for us either.

What can we do to reduce if not eliminate lead from 100LL? There are several possibilities:

1. Use turbine power. We note that the Cirrus SF-50 Vision, which uses a single Williams International FJ33 pushing on the upper rear fuselage and whose exhaust blows between two V-tail ruddervators, was recently certified. We have seen several single engine turboprop planes in recent years, and there are light turbine-powered helicopters out there too such as the Robinson R66.

2. Use ethanol. E-85 fuel (85% ethanol and the rest, gasoline hydrocarbons) might require modifying both the engine itself and the whole fuel system, but its high octane rating would take care of knock issues. A big disadvantage of E-85 is lower energy content, hence aircraft so fueled cannot fly as long or as far as with 100LL. But an E-85 powered aircraft might still have more range/endurance than an all-electric aircraft.

3 Use Diesel power. If Diesel engines prove to be acceptable from the exhaust emissions standpoint and if they are satisfactory in other respects, they too will help reduce our lead problems.

4. Electric aircraft. If you only need an hour or so endurance for flight training purposes, they could be used for such. A big disadvantage is: when the batteries run down, what's the recharge time?

5. Use 93 (or is it 94) octane avgas, i.e. 100LL with the lead removed. This will result in reduced performance because of knock issues. Aircraft flown mainly for the sheer fun of being airborne (i.e. light sport aircraft), could use 94UL with no problems.

Using one or more of the above options, depending on one's particular needs and situation, will hopefully reduce lead emissions to acceptably low levels. We might still have some lead emissions owing to continued use of 100LL in vintage aircraft.

Posted by: Alex Kovnat | October 31, 2016 8:30 AM    Report this comment

Alex ... you forgot option #6 ... drive existing pilots insane such that they go away. Maybe option #7 ... make the cost SO prohibitive that the only way to fly would be via VR glasses and drones. Neither requires an alternative no lead fuel and coincidentally achieves the FAA / NTSB safety goal of less than 1 fatality per 100K hours. No pilots = 100% safety.

Expensive ADS-B installations if you want to occasionally use all the airspace, no lead fuel, inspections galore, flight reviews and all the other irritants... and all of that with a dwindling number of airplanes and pilots. Hmm ... the FAA wants the above safety rate by 2018 ... same year as the new fuel. Coincidence? YOU decide.

When I pickle my airplanes and ground vehicles up north, I put 100LL in 'em because the stuff can sit and doesn't go bad. When I leave my cars (which can't have lead in the fuel), I have to use fuel stabilizer. I wonder if anyone has addressed THAT aspect of any new fuel ... long term storage?

Posted by: Larry Stencel | October 31, 2016 9:22 AM    Report this comment

It's unfortunate that the big bad government didn't get the lead out of GA 40 years ago like they did with automobiles. All this bellyaching would be ancient history by now, and GA engines would be running perfectly fine on no-lead fuel like cars do.

Posted by: Rollin Olson | October 31, 2016 9:46 AM    Report this comment

Thank you Larry for pointing out that there are those whose attitude towards airplanes is like the attitudes we see towards cars and driving. As many of us are aware, there are proposals to automate driving to the point where cars will be built without a steering wheel. Advocates of totally automated driving have been known to say that, in light of tens of thousands of Americans being killed in traffic accidents every year, driving one's own car should be either outlawed or the insurance rate be made prohibitive.

One question I have asked regarding totally automated driving and totally automated roadways is, where will motorcycles fit in with this techno-utopia? All who ride and love their Harleys (or whatever motorcycle they ride) will tell you that the destination is not why they ride; the experience of being in control of a powerful and maneuverable machine is. One wonders if motorcycles might be outlawed (along with sport cars) supposedly because of safety concerns, but the real reason would be that the spirit of freedom that's inherently a part of riding doesn't fit in with the dictatorships we may be forced to live with in the next few decades.

Same with aircraft. Given all we hear about the world supposedly coming to an end from global warming or carbon dioxide-induced global climate change, the powers that be in coming years may very well seek to, in effect, ban flying for the sheer fun of it.

Posted by: Alex Kovnat | October 31, 2016 9:47 AM    Report this comment

The FAA and Shell had to have known about the properties of this fuel during preliminary testing, before it was down-selected. How could it have ended up one of the top 2 fuels for extensive testing?? This smells of heavy lobbying by Shell to move their entrant into the running, despite its lack of usability as a direct replacement for 100LL.

Posted by: BRUCE POULTON | October 31, 2016 11:52 AM    Report this comment

I don't see why we have to have the government trying to pick one specific "winner". Why not simply set performance standards that replacement fuels have to meet, and allow competition in the marketplace?

Either way, I'm building my RV to be ethanol-tolerant.

Posted by: Robert Gatlin-Martin | November 1, 2016 9:17 AM    Report this comment

Robert, government's role is not to solve problems but exert control. Ever see a bureaucrat get fired for not solving a problem? Neither have I. Until we have a fundamental change in the role of government, we are stuck with half baked, expensive or impractical solutions to problems. It is not just the FAA but the whole DC mentality. Their consultants with degrees from prestigious colleges and universities are, in their minds, the only people on earth who can solve any problem.

The free market will as you have mentioned will solve problems. The problem in the US is not competition but government inhibition of competition to protect the weak, inept or incompetent businesses who are able to lobby their case for protection.

Posted by: Leo LeBoeuf | November 1, 2016 12:03 PM    Report this comment

Leo ... at my northern outpost airport, we needed a new fuel pit after a new FBO was built. It took years for the paperwork at the Federal, State and local levels to get processed and approved. Once the "red button" was pushed for private enterprise to come in and do the work, it got done in 3 weeks ... THREE WEEKS !! And that was not only a new fuel pit but taking out the old one.

Amazing what the profit motive does for free enterprise, as you say.

Posted by: Larry Stencel | November 1, 2016 2:07 PM    Report this comment

Like Obamacare is designed to kill private insurance companies the AV gas "issue" is designed to drive GA out of America's skies. Let the free market prevail and get the over regulation monkey out of our gas tanks.

Posted by: bruce postlethwait | November 1, 2016 6:22 PM    Report this comment

Don' t be afraid. There will be unleaded AVGAS to use in the future. In Sweden we have been flying for 36+ years on unleaded AVGAS produced as per
the US standard D910 which is the same standard as 100 LL. Thousands and thousands of planes have flown millions and millions of hours at any possible weather and temperatures without any problems, and for sure no paint has fallen of any aircraft. Unfortunately the PAFI group decided to exclude our fuels and also our technical solutions that already today make our fuels satisfying practically 100 % of the fleet with known and proven fuel components and technology.
The US customers have to ask themselves -- what happened?
Elsewhere in Europe you can find unleaded AVGAS as per US standard D7547 in practically almost every country where there is demand. You can fly from the Mediterranean to North Cape on unleaded AVGAS. Four out of the 5 AVGAS producers in Europe produce unleaded AVGAS for the existing market.
I invite Avweb to start to research. Both fuels tested by PAFI have for the public open patent applications and well as for the public open ASTM test standards.
It is not too complicated to start to put up questions and search for answers.

Posted by: Lars Hjelmberg Hjelmco Oil Sweden | November 2, 2016 5:40 PM    Report this comment

Just wondering why there hasn't been more coverage regarding STCs for Electronic Ignition in AC engines. This would seem to go hand in hand with the need for lower octane fuel/unleaded fuel. As it would appear to this non engineer that in order to make this a reality most high compression AC engines will need to be able to adjust their timing on the fly i.e. electronic ignition. So my question why doesn't the FAA help to speed up the issuance of STCs for the E-Mag for example? The company is working on a certified replacement for both my Mags on my D model IO540 (D= dual). I have a high compression Turbo Charged IO 540 and I fear without EI, it will self destruct due to excessive detonation, which I'm sure the fuel guys are fully aware of but why overlook the timing issue? Thanks for letting me get that off my chest. Appreciate the articles.

Posted by: Marty Rogers | January 2, 2017 5:13 PM    Report this comment

I'm hoping that there will be another progress report at Oshkosh this week and that we'll see another article from you on this matter. It is a serious issue for those of us that are having to make decisions in the near future about overhauling or exchanging their engines. The IO-360 in my Mooney is making metal and I would really like to know NOW (i.e. before spending $40-90k) whether the potential replacement engines will operate on the replacement fuel. The engine companies are involved in the testing so must have a pretty good idea by now of how this is likely to play out.
Also, as you know, there are very few refineries that make avgas and I'd also be interested to know how many of them will be able to make the replacement fuel. The replacement will require very high octane components that some refineries may not be able to make.

Posted by: John Hillard | July 26, 2017 12:25 PM    Report this comment

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