Unleaded Fuel Reset: Is EAGLE The New PAFI?

The path to lead-free aviation gas takes yet another unexpected detour with the EAGLE industry initiative. Haven't we seen this before?

The FAA’s EAGLE initiative stands for Eliminate Aviation Gasoline Lead Emissions, and many are asking how it differs from PAFI (Piston Aviation Fuel Initiative), which fell apart in 2018 when the agency suspended its efforts. 

Moreover, will EAGLE’s outcome be any different than the last 31 years of FAA unleaded avgas initiatives? And what is the longer-term significance to the aircraft owner and pilot? Let’s think about this, shall we?


EAGLE was introduced by FAA Administrator Steve Dickson at the GAMA (General Aviation Manufacturers Association) annual conference on Feb. 23, 2022. That was a fitting venue, since GAMA is a major force behind EAGLE. But, the rest of the alphabet groups are engaged as well, including AOPA and EAA. The GAMA members (Lycoming, Continental, Cessna, Beechcraft, Cirrus, et al.) want an unleaded fuel that works, to ensure that the GA industry moves forward. But even more importantly to them, the GAMA members want any new fuel to be structured so that it does not become a major liability headache for the manufacturers. Administrator Dickson, who had previously announced his upcoming retirement, commented that EAGLE may seem like unleaded avgas “déjà vu all over again.”

Why is engine and airframe manufacturer liability a concern for a fuel? To use an example offered confidentially by one of the manufacturer’s reps: Say Joe and Sam invent the world’s greatest unleaded avgas. And they start manufacturing, distributing and selling it. But, for whatever reason, there’s a problem. Maybe a pilot doesn’t use the fuel appropriately in his 172. Or, someone contaminates the fuel. Some weird thing happens. Joe and Sam get sued. But, everyone else gets sued too, because that’s how it’s done these days. The courts decide that Joe and Sam made a mistake, whether they did or they didn’t, but Joe and Sam don’t have any assets. 

So, under joint and several liability, Cessna and Lycoming, who are perhaps only held one percent liable for the event, get to pay the entire judgment. “That’s something we can’t afford,” the rep noted.

Or consider that Joe and Sam’s fuel works great, but it turns out that it corrodes certain Lycoming camshafts, and Lycoming gets a bunch of warranty claims. How can Lycoming prevent this problem if it doesn’t get to extensively test the fuel before it’s introduced?

Joe and Sam, of course, respond that they’ve tested this fuel for over a decade, their distribution practices are the best in the industry and these worries are just not realistic. But of course, that’s not all that reassuring for the folks writing checks among the GAMA members. Anyway, that’s why GAMA and their members are enthusiastic about EAGLE, but what’s in it for the rest of us?


The latest March 2022 EAGLE industry meeting was kicked off by Dr. Amy Pritchett, of Penn State University, discussing the National Academy of Science (NAS) report on “Reducing Lead Emissions from Piston-Engine Aircraft.” The study concludes that there’s a problem with no clear solution. But to put that in perspective, one has to contemplate that in asking for the study, Congress specifically told NAS to ignore the unleaded fuels under development. It’s kind of like asking someone to evaluate treatment of diabetes—but just don’t talk about that pesky insulin stuff. In our view, the NAS team had at least one hand tied behind their backs, and as a result, their recommendations were a bit of rearranging the deck chairs on the Titanic, ignoring the fundamental shift that’s coming to unleaded avgas.

The EAGLE meeting was then tag-team led by the FAA’s Earl Lawrence, also known as AIR1, responsible for certification activities, and AOPA’s president, Mark Baker. Earl and Mark made it clear that EAGLE is motivated by the threat of an EPA endangerment finding on lead in avgas, and the confusion that could ensue if more localities follow Santa Clara County (California) into discontinuing sales of leaded avgas, offering instead 94UL, or nothing. Note that two-thirds of the avgas demand requires 100 octane fuel, so 94UL is not a solution for the majority of the avgas demand.

The FAA then outlined a list of curious focus areas, starting with the failed PAFI.

• PAFI, which began in 2013, involves the FAA choosing the winners, and then further developing those fuels. The first two FAA chosen winners ended up withdrawing from PAFI after five years when timely success under PAFI’s rules appeared unlikely. Shell has chosen to sit on the sidelines for now; Swift Fuels has chosen to follow the STC route to fuel approval. The FAA then reincarnated PAFI with two new participants they solicited, Phillips 66 and Lyondell (most of us are probably most familiar with their ARCO Chemical entity). Oddly, even the names of these participants aren’t revealed by the FAA. And there’s no open reporting on problems or progress. Reports are that success, if it comes, is five years away. It’s not evident why this secret process will be any more successful than the FAA’s last try. And many are pointing out that research being funded by U.S. tax dollars is not being made available to the industry to use in trying to solve this problem.

• Streamlining an approval process and the elusive “fleet-wide approval” goal for unleaded avgas. The FAA confusingly differentiates between “fleet-wide approval,” which refers to PAFI fuels, and fleet-wide approval (without quotes), which refers to STC candidates GAMI and Swift Fuels. The FAA intends to treat these fuels differently, though the FAA’s Lawrence admitted this past November that it didn’t have to treat them differently. Part of the streamlining is that “fleet-wide approved” fuels won’t require filing an FAA Form 337, at least right now. The FAA has vacillated on that point. Fleet-wide approved fuels may require filing a 337, except the engine and airframe manufacturers have been doing a fair job of keeping up and adding new fuels (like Swift’s 94UL) to their approved list, in which case a Form 337 is not required. Should the agency really pick winners in the marketplace? Given the time frames, we wonder if the process is anything but the streamlined process that the FAA promises. More concerning is that while the FAA has told GAMI (in writing) that its fuel meets all the requirements for fleet-wide approval (no quotes), that approval is being withheld, perhaps to avoid overshadowing EAGLE.

• Unleaded fuel infrastructure options, including availability of multiple unleaded fuels that cover the entire fleet. But nobody wants multiple octanes, including the fuel producers. As for the rest of the industry infrastructure, unleaded and leaded avgas requirements are pretty much the same, and of course, already in place. That’s the beauty of at least the Swift Fuels and GAMI approaches; their unleaded fuels promise to be completely mixable in the system with leaded fuel, allowing a gradual transition with no cleaning of tanks required. Moreover, from what we know it doesn’t seem likely that Phillips 66 or Lyondell’s fuels would require infrastructure changes—yet, the infrastructure is being studied.

• Engine replacement technology—an option none of the fuel developers understands to be needed. If we did need engine technology development, shouldn’t companies like RAM or GAMI—that have a proven track record—be doing it, instead of the FAA Technical Center that’s been diddling with unleaded avgas, unsuccessfully, for 31 years? We think so. Using taxpayer money, the FAA also plans to evaluate electric airplane technology, but there’s no path from that to solving the remove-the-lead-from-avgas problem, since we only replace about one percent of the fleet per year. In fact, in the unleaded avgas stakeholder meeting last November, GAMA and others were quite forceful in pointing out that the FAA needs to focus on unleaded avgas, and not diversions like electric airplanes. 


EAGLE is structured as four “pillars” or committees supporting the overall goal of eliminating lead from avgas. Just exactly what the committees will be doing varies a bit from FAA presentation to presentation, and the FAA’s view on how all this might work continues to evolve significantly, from the November 2021, January 2022 and March 2022 industry meetings the FAA has sponsored as unleaded avgas roundtables, with over 100 participants each time. 

The FAA and GAMA have proposed agendas for the four pillar committees, two led by industry, and two led by the FAA. The agendas have been very dynamic, with lots of changes; the FAA emailed all pilots (for whom they had email addresses) in January 2022, outlining the pillars. 

Here’s the March 2022 version, with the desired outcomes from those committees.

Pillar A: Industry-led business (fuel) infrastructure and implementation.

• Support standards and regulatory pathways for quality, production and deployment.

• Support government incentive and policy programs to accelerate UL transition.

• Environmental, social and governance outreach.

• Address complexity: This is maintaining 100LL availability and safely deploying UL avgas.

• Education, training, awareness and outreach.

Pillar B: Industry-led research, development and innovation.

• Facilitate UL transition by mitigating fleet impacts and enabling innovation.

• Address safety and technology challenges, plus the R&D of advanced tech designs.

• Effective and timely FAA certification.

• Education, training and outreach.

Pillar C: FAA-led evaluation and authorization of safe unleaded fuels.

• Address fleet-wide authorization of unleaded avgas of different octane levels.

• Piston Aviation Fuel Initiative—evaluate, test and qualify.

Pillar D: Government-led regulatory, policy and programmatic activities.

• Regulatory certainty, programmatic support to airports, engine retrofits swaps.

• Incentive for the industry to develop no-lead avgas technologies.

These descriptions are a bit light on action words, but presumably the committees will puzzle over this direction and come up with action plans.


The EPA’s Bryan Manning and Marion Hoyer made a presentation, pointing out that lead is bad for children, and that the EPA is moving forward to investigate an endangerment finding. Others within the EPA point out that there are firm guidelines for what constitutes endangerment, and that the data on avgas lead may not meet those criteria. The investigation is launching, and we should know the results next year. 

If the EPA makes an endangerment finding, that launches rulemaking. But, the Supreme Court has ruled that the FAA—not the EPA—is the regulator of avgas composition. So any endangerment finding that results in EPA rulemaking will then launch FAA rulemaking into regulating the lead in avgas. The FAA’s Earl Lawrence estimated that was a four-year process. And when that regulation comes out in 2025, assuming the EPA does justify an endangerment finding, there will then be a lead phasedown period, perhaps five years, consistent with the 2030 target year. So there may be an endangerment finding—or there may not be.

But there are many good reasons to move toward unleaded avgas in either case: community acceptance of general aviation, clean-running engines with longer oil change intervals, longer spark plug cleaning intervals, the end of exhaust valve sticking, the possibility of new, specially formulated synthetic aviation oils for longer engine life and lower operating temperatures (but please do not put automotive synthetics in your airplane engine; the additive package is incompatible), the threat to the tetraethyl lead supply from manufacturing economics and environmental regulation (already outlawed in Europe). Hopefully if there is a lack of an EPA endangerment finding, this won’t distract the troops working to evolve our next generation gasoline.


Interestingly, Phillips 66, a PAFI participant, has been throwing rocks at the independent unleaded avgas developers, first heard at the NBAA (National Business Aircraft Association) convention in Las Vegas last October, and since added to by Phillips functionaries at the FAA unleaded avgas stakeholder meetings. Phillips is a competent company, and certainly it has people who know the claims they’re making are contrafactual (that’s the Washington, D.C., way of saying it). Others in the industry have pondered this phenomenon.

One major avgas producer’s analyst commented: “It appears that Phillips is just trying to ride the lead donkey another decade! It is giving lip service to unleaded avgas development via PAFI, with a formulation that’s not likely to succeed, at least in its present form. And it’s casting shade on the unleaded avgas development efforts of others, in an effort to create fear, uncertainty and doubt (FUD) among the blenders of avgas.”

But, what about the Santa Clara County study on the impact of lead? Reid-Hillview pilot and engineer Michael McDonald calls foul on the county’s study. Beginning by noting that we need to transition to unleaded avgas, McDonald points out that the county’s study is flawed, and only serves to cause unnecessary angst and consternation. Based on this flawed study, the little league fields near the airport have been closed, a needless loss to the community based on misinterpreted data, he says.

“The county needlessly creates unwarranted concerns for all families living near airports and unreservedly devalues all communities near airports. They are not helping these communities as they profess; they are hurting them and redirecting scarce health resources in the wrong direction,” McDonald notes. McDonald points out that the lead plume predicted by the study doesn’t match the actual data. But, in fact, there are many other sources of lead in the community, most notably the many decades of use of lead arsenate, an environmentally persistent insecticide, as the area was originally all orchards. McDonald asserts that if the county was really interested in whether aircraft use was causing lead toxicity, they’d characterize the lead found in the soil to determine if it’s from automobiles, agriculture, the nearby racetrack that used very high leaded fuels for decades—or from airplanes. 

Most simply, now that the airport has discontinued sales of leaded avgas, a prudent county would repeat the analysis to see if lead levels were falling … if they really want to know if the airport was causing the problem. But, as McDonald explained, the county is looking for an economic windfall by selling the airport’s land to developers, so they don’t want the truth. They just want justification to close the airport.

The local air pollution regulator, the Bay Area Air Quality Management District (BAAQMD), has been monitoring airborne lead levels near the airport for decades. But, lead levels near the airport are so far below EPA standards that BAAQMD plans to stop monitoring. McDonald says that this makes it clear that there is no crisis here, other than the political one manufactured by the county.

The bigger concern is that other airports may follow along based on Santa Clara’s “data,” and indeed other airport communities in California and other states have been proposing just such limitations on their airports. Our GA infrastructure could crumble if two-thirds of the fuel supply is compromised over non-factual rumors.


Lead needs to go away for good reasons, but many believe that folks are capitalizing on that effort for their own political purposes. In our opinion, the FAA has not been an efficient steward of this problem over the past 31 years, and it’s natural to wonder if it’s wasting federal dollars. 

But, two upstarts, Swift Fuels and GAMI, have fuels that will work, if only they can get the FAA to issue STCs based on the companies’ demonstration of compliance. When these fuels do come to market, they promise aircraft owners a number of sizable operational advantages.