Sunday, May 29, 2022

Federal Aviation Administration indicates ban coming on leaded gas for small planes

Earlier this year, the Environmental Protection Agency issued a statement that many felt was long overdue.

In January, the federal agency announced it would “evaluate whether emissions from piston-engine aircraft operating on leaded fuel contribute to air pollution that endangers public health and welfare.”

The EPA said it would issue a proposed “endangerment finding” for piston-engine aircraft that run on leaded fuel. The public review and comment process will take place in 2022 and final action will be taken in 2023.

The decision was more than a decade in the making.

In 2012, Friends of the Earth and Earthjustice filed a lawsuit against the EPA, challenging the agency’s failure to respond to a 2006 petition from Friends of the Earth asking for the regulation of lead emissions from general aviation aircraft under the Clean Air Act. In 2014, the same groups, along with Oregon Aviation Watch, a public advocacy group based in Hillsboro, petitioned the EPA to make an immediate endangerment finding.

The agency denied the petition.

While levels of airborne lead in the United States have declined 99% since 1980, according to the EPA, small, piston-engine aircraft that still operate on leaded fuel are the largest remaining source of lead emissions into the air.

“Protecting children’s health and reducing lead exposure are interlocking priorities at the core of EPA’s agenda,” said EPA Administrator Michael S. Regan in the January statement. “EPA has been investigating the air quality impact of lead emissions from piston-engine aircraft near airports for years, and now we’re going to apply that information to determine whether this pollution endangers human health and welfare.”

The agency finally appears ready to do something about leaded aviation fuel, or “avgas.”

Questions remain. What does a realistic solution look like? And when will it come?

Small planes loophole

Lead as a toxic byproduct of burning gasoline in engines isn’t news.

In 1970, the EPA worked with the U.S. Congress passed the Clean Air Act, which initiated a phase out of leaded gasoline for automobiles that concluded in 1995.

But piston-engine airplanes (along with some farm machinery and heavy equipment) have been exempt from lead restrictions since 1996.

The primary reason is safety.

Tetraethyl lead is a heavy metal compound that’s added to avgas to prevent premature detonation or knocking. Aircraft engines must avoid knocking or risk sudden, catastrophic failure. Unlike car drivers, pilots can’t pull onto the shoulder and call for help when their engines fail.

There are about 170,000 piston-engine, general aviation (civilian) aircraft in the United States. Among states, Washington and Oregon rank 4th and 14th, respectively in the number of registered general aviation aircraft. Most of these burn 100-octane low lead gasoline, commonly known as 100LL.

In February, the Federal Aviation Administration announced its new EAGLE (Eliminate Aviation Gasoline Lead Emissions) initiative, a plan that details the elimination of leaded aviation fuel by the end of 2030.

Getting unleaded avgas to market

Oklahoma-based General Aviation Modifications, Inc. (GAMI) is currently the only commercially viable producer of 100-octane unleaded avgas, which it plans to distribute under the name G100UL.

In a telephone interview with Columbia Insight, Timothy Roehl, GAMI president and patent holder on G100UL, outlined the difficulties in bringing unleaded avgas to the market by 2030.

The company must first obtain a “Supplemental Type Certificate” approval from the FAA. The certificate grants permission to an applicant to modify an aeronautical product from its original design.

Roehl hopes general aviation aircraft in the United States will be certified to burn G100UL before the end of 2022.

Cost, however, is another obstacle.

“GAMI and its licensed producers’ cost to make G100LL will be 50 to 60 cents higher per gallon than 100 low lead fuel,” he said. “But that’s offset by longer times between engine overhauls and also longer intervals between oil changes.”

More time between engine maintenance is a byproduct of burning lead-free avgas.

This sounds promising, but GAMI has already experienced lengthy and unexplained delays in obtaining government approvals for its products. Why?

“Politics. Follow the money,” said Roehl, referring to the lobbying power of major refiners of leaded avgas.

He’s not the only one wary of a political derailment.

“One of the concerns we have is how can we finalize [a ban on leaded avgas] under the Biden administration. What’s to stop a new administration from once again postponing and delaying on these issues?” says Miki Barnes, founder and president of Oregon Aviation Watch. “Even once it’s finalized there are groups that can delay this, and that includes the aviation industry organizations that want to continue using leaded fuel.

“Big lobbyists pump a lot of money into the pockets of political people. Oregon (Congress members) Peter DeFazio, Ron Wyden, Jeff Merkley, Suzanne Bonamici, Kurt Shrader, all of these people are recipients of money from general aviation lobbyist organizations. All of those members are on the Congressional General Aviation Caucus. Not one has spoken out about eliminating leaded aviation fuel.”

How bad is the problem?

As previously reported by Columbia Insight, while general aviation is a small part of overall aviation, it’s a significant source of local lead exposure.

A 2011 study reported that about 16 million Americans lived within 1 kilometer of a general aviation airport, and 3 million children attended school within that perimeter.

The closer the residence to the airport, the higher the blood lead levels in the children living there. Airport lead levels have been measured at more than four times the concentrations found in the general environment.

Exposure to high levels of lead may cause anemia, weakness and kidney and brain damage. Very high lead exposure can cause death. Generally, lead affects children more than it does adults.

The most significant sources of airborne lead in Oregon and Washington are airports. According to Oregon Aviation Watch, Hillsboro Airport is Oregon’s top emitter of airborne lead—in 2016 it released nearly twice the emissions measured at Portland International Airport.

According to Barnes, the Hillsboro Aero Academy training program, which trains pilots from more than 75 countries, is a major contributor to airborne lead.

In March, the attorneys general of 18 states, including Oregon, sent a letter to the EPA “Concerning EPA’s Draft Strategy to Reduce Lead Exposures and Disparities in U.S. Communities.”

“The most recent emissions data from EPA show that these planes [piston-engine aircraft] released more than 930,000 pounds of lead into the atmosphere in 2017, and emissions from the general aviation sector are expected to increase in the coming years,” read the letter. “The Federal Aviation Administration predicts sector emissions will reach 1.5 million pounds per year by 2025—a 66% increase in emissions from 2017.”

Though the EPA seems committed to action, it remains unclear what percentage of those future emissions will come from leaded avgas.


  1. Looks like the political landscape will change dramatically in November

    1. No matter what side your political views might go toward, it should be obvious by now that the all-encompassing greenie push to unmake the modern world won't be stopped by changing which politicians are seated.

  2. Is this going to be you have to purchase the STC or you can’t fly? Cuz that (figuratively and literally) won’t fly.

  3. I have a high compression Lycoming IO-360. There is no STC.

  4. Just what GA/Flight Schools needs when there is huge Pilot shortage and unafordable training cost...I guess send all the Flight Schools to Mexico...

  5. Or hire foreign pilots like we hire foreign engineers and doctors.

  6. C'mon, man! We all need to realize that this is another forcing function scheme to set up "credits" or "offsets", which used to be called "buying indulgences".

    The way this always plays out is:
    1. A "sin" is identified (lead in the fuel).
    2. Action is proposed.
    3. Realization of impact sets in.
    4. An offset/buy credit scheme is launched.
    5. Some get to continue by paying the sin tax.

    They trained your mind with the "planted a tree to offset airline travel" stories, Musk's electric car offsets bought by fueled vehicle and the absurd corn ethanol program.

    People in the know understand that general aviation has to be squashed under "pay to play" so that only the most well-heeled are still competing with Amazon delivery drones for airspace.

    Soon as Avgas is whipped, your steak and hamburger sin is next!


  7. There seems to be an agenda to eliminate general aviation small piston airplanes. The airlines and corporate aviation would like to see small pistons fade away. The public doesn’t really understand small airplanes and the media tries to paint a picture that isn’t accurate, either.

    1. So true, counting all the dead passengers in recent plane crashes is a tell tale sign people have no idea what GA entails or the high risk envolved esp. when pilots have zero skills and common sense...

    2. Around 40k dead each year in car crashes. Time to eliminate cars or at least reduced the speed limit to 30 mph.