Unleaded Fuel Transition Plan to Be Unveiled Public Comment DEADLINE March 13, 2026

January 12, 2026

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by Russ Niles (AvBrief) The FAA may lay its cards on the table on just how it’s going to have all piston aircraft burning unleaded fuel within the next five years. The agency will issue its Draft FAA Transition Plan to Unleaded Aviation Gasoline in the Federal Register sometime on Jan. 12. The notice that it was happening appeared on Friday, and it says the document will lay out what the agency thinks should happen. “The comprehensive framework outlined in this transition plan encompasses fuel authorizations and comparison testing, market experience, and the national transition to unleaded fuel(s).” We will update as we get more information.

The agency seems to be leaning heavily on public input to help guide this process, which has been underway in one form or another for more than 30 years. It gained urgency about three years ago with a formal “endangerment finding” by the Environmental Protection Agency on the lead emissions from piston aircraft. “The FAA is seeking public comments on the draft FAA Transition Plan to Unleaded Aviation Gasoline to facilitate a structured, safe, timely, coordinated, and orderly transition to unleaded aviation gasoline alternatives while maintaining the operational efficiency of the general aviation fleet,” the Federal Register document says.

The FAA is a partner in the Eliminate Aviation Gasoline Lead Emissions (EAGLE), which is tasked with assessing three candidate fuels for the job. Each of those candidates is following a different path toward acceptance of their fuel. GAMI’s G100UL already has Supplementary Type Certificate approval by the FAA for its use in all certified piston aviation engines, but the company is resisting getting an ASTM International fuel specification. Swift Fuels has also gone the STC route but is also getting an ASTM spec. It has so far only achieved STC approval on late model Cessna 172 R and S models. Lyondell/Basell and VP Racing’s fuel is last in the FAA-run Piston Aviation Fuel Initiative (PAFI) testing regime, but the company has repeatedly warned that some engines will need paperwork or physical modifications to use its fuel. We’ll have details on the FAA plan as soon as they’re released. READ MORE

Related articles

FAA Publishes Unleaded Avgas Transition Plan Draft (AvWeb)
FAA’s Rocheleau Admits Unleaded Avgas Timeline May Slip (AIN Online)
FAA finalizes 100LL phaseout plan but leaves key details unresolved (AeroTime)
Transition Plan to Unleaded Aviation Gasoline July 2026 (Federal Aviation Administration)

Excerpt from AvWeb: Agency outlines a phased approach to replacing leaded aviation gasoline nationwide in a newly published draft, which is open for public comment.

The FAA released its draft Transition Plan to Unleaded Aviation Gasoline for public comment Monday, outlining its proposed approach to eliminating leaded avgas from the general aviation fleet.

The plan was developed in response to Section 827 of the 2024 FAA Reauthorization Act, which directs the agency to facilitate a safe, timely and orderly transition to unleaded alternatives while maintaining operational efficiency.

The 77-page draft document establishes a national goal of phasing out 100-octane low-lead aviation gasoline by 2030 in the contiguous United States, with Alaska following by 2032.

The transition framework to unleaded avgas is built around four phases, beginning with fuel authorizations and comparative testing, followed by a period of market experience, a national transition and a final phase specific to Alaska. The plan builds on work conducted under the Eliminate Aviation Gasoline Lead Emissions (EAGLE) initiative, a government-industry collaboration launched in 2022.

The FAA said the framework is intended to support approval of unleaded fuel options for all piston-engine aircraft, ensure continued availability of aviation gasoline and promote widespread access to unleaded avgas at airports.

The agency is requesting comments from stakeholders on the draft plan through March 13, 2026. Public input will help inform refinements to the plan as it continues to work with industry and federal partners toward meeting the congressionally mandated unleaded avgas transition timelines. READ MORE

Excerpt from AIN ONline: Deadline of Dec. 31, 2030 may have to be moved if a suitable fuel isn't available

FAA Deputy Administrator Chris Rocheleau suggested during EAA AirVenture Oshkosh this week that the timeline for unleaded fuel would be pushed back and stressed that the FAA would not move forward without ensuring any aviation gasoline drop-in replacement is safe.

During a Meet the FAA Administrator session yesterday, Rocheleau was asked whether the government-industry EAGLE coalition will meet the Dec. 31, 2030 deadline to replace leaded avgas with an unleaded fuel. The goal is to make a suitable alternative to leaded 100LL avgas available for all piston aircraft engines by the deadline. EAGLE stands for Eliminate Aviation Gasoline Lead Emissions initiative.

“We don't do this in a vacuum,” Rocheleau said. “We have been working very closely with the different community members and associations to make sure that we're going to do this carefully, intentionally, and not say, ‘Well, this is a solution, and we’ll call it a day.’ The timeline is aggressive. In the coming weeks, we're going to issue a new roadmap to reset what I think expectations are.”

Rocheleau added that he's learned since becoming deputy administration that as soon as a date is set, someone changes it. "So part of this is making sure that we're working with the EAGLE participants," he continued. "I think it’s aggressive, and I can tell you with confidence we’re not going to set an arbitrary date that says, ‘Well, this is what it says, without making sure that whatever we're going to put in those aircraft isn't safe.’”

That said, Rocheleau does have concerns about other facets of this problem. “I feel comfortable being part of the EAGLE program that the testing timelines will be met. I think the more complicated part of that puzzle is the petroleum manufacturers, as to what it's going to take them to potentially convert their factories to be able to produce in the field, and then the distribution process.”

Fuel experts have told AIN that it will take 18 to 24 months to ramp up the distribution network, although unleaded fuel manufacturer Swift Fuels is already delivering its fuel to a number of airports in the U.S. and Europe and says it can grow its distribution network much faster.

In any case, the FAA reauthorization bill that reinforced the avgas deadline does, he added, “ensure that there will continue to be leaded fuel available until that successful transition takes place, no matter what the date [is].” While people worry that tetraethyl lead manufacturer Innospec will stop making that product, which is the essential component of leaded avgas, Rocheleau said, “That’s not the case.” READ MORE

Excerpt from AeroTime: The Federal Aviation Administration (FAA) has released its final plan for eliminating leaded aviation gasoline across the US, keeping a 2030 deadline even as major questions remain over fuel selection, cost and needed aircraft modifications.

The 72-page plan lays out a four-phase transition from 100LL to unleaded avgas. It calls for leaded fuel use to end outside Alaska by December 31, 2030. Alaska would have until the end of 2032 because of its remote airports, limited storage and difficult fuel-distribution network.

The FAA has not set firm start dates or detailed schedules for the final two phases, which cover the nationwide transition and the later changeover in Alaska. The agency expects to publish an updated plan in late 2027 after completing the first phase.

Phase 1 will compare three high-octane unleaded fuels: General Aviation Modifications Inc.’s G100UL, Swift Fuels’ 100R and LyondellBasell and VP Racing Fuels’ UL100.

The FAA said testing will examine engine performance, detonation resistance, material compatibility and fuel composition. It will also study what happens when each unleaded fuel is mixed with 100LL or with a competing unleaded product.

The FAA expects to complete that work in spring 2027. Phase 2, scheduled to run through mid to late 2028, would expand use of approved fuels and allow aircraft owners, airports, flight schools and fuel suppliers to gain operating experience.

Each fuel developer supports mixing its product with 100LL in an aircraft tank, though none currently supports mixing its fuel with another company’s unleaded avgas.

The plan also makes clear that approval of an unleaded fuel will not automatically clear every aircraft to use it without further action. READ MORE