What If We Looked At 100LL Differently?

For years now, the aviation fuel discussion has mostly centered on one question: How do we get the lead out?

And that makes sense.

But maybe there is another question worth asking.

How do we reduce lead emissions while still burning 100LL that many aircraft engines were designed to use?

That is what caught my attention in a presentation at EAA AirVenture Oshkosh 2026 by Patrick Ealy, a master’s thesis candidate at the University of North Dakota. Ealy’s research does not argue that lead is harmless. Instead, it asks whether the issue — lead — is being framed too narrowly.

As Ealy put it, “The best way to reduce emissions is to reduce your fuel burn — how much of the stuff you are using.”

That is a practical place to start.

Ealy’s proposal has three parts.

First, install high-energy, variable-timing electronic ignition systems where practical. Burn less fuel and less lead goes into the atmosphere. The presentation highlighted early observations showing “20% to 25% savings,” adding that the technology “is available in the certified world.”

Second, move toward 100VLL, a very-low-lead version of avgas. Ealy framed this as “a stepping stone” and that phrase matters. Too often, the fuel conversation becomes all or nothing — either aviation gets the lead completely out or no progress counts. That seems like a poor way to solve a practical problem.

Ealy asked, “How many fewer tons of lead would be in the air, how much lower would the lead level be in the blood of our children, if we took a sensible approach and adopted technology as it was available?”

That’s a good question. It deserves an answer.

The third part is the one that really sticks with me: Capture lead before it leaves the airplane.

This concept relies on a lead-collecting anode in the exhaust stream. In simple terms, instead of focusing only on what goes into the fuel tank, Ealy’s idea asks what might be done about what comes out of the exhaust pipe.

“I believe we can sequester lead from the emissions and actually further reduce it significantly,” Ealy noted. “We can actually sequester it, hold it on the aircraft, and wipe out this anode at oil change periods so it’s no longer being emitted.”

That’s an interesting idea.

And that’s where it exists: An idea.

It would need engineering, testing, certification, maintenance procedures, cost analysis, and a clear answer for handling the captured lead. It would also need to prove it does not create new safety risks or maintenance headaches.

But aviation has solved hard problems before.

What I appreciate is how Ealy is reframing the topic. Much of the public discussion treats the continued use of 100LL as a moral failure. Ealy’s proposal treats it as an emissions challenge.

Aircraft owners are not refusing unleaded fuel because they enjoy lead. They want fuel that works in the airplanes they own, at the airports they use, in the conditions they fly. They want safety, availability, affordability, and trust.

Those are not unreasonable wants.

Maybe the lead-capturing exhaust filter is not the answer. Then again, maybe it is.

Regardless, it is the kind of question general aviation should be willing to ask.