FAA Issues Draft Framework for Unleaded Avgas Transition

The FAA has released its draft Transition Plan to Unleaded Aviation Gasoline, providing an overview of a four-phase process for national rollout or a replacement for aviation gasoline. Notice of the plan was included in the January 12 Federal Register, with comments due on March 13.

As required by the 2024 FAA Reauthorization Act, the plan addresses steps to ensure the safe elimination of leaded fuel, approval for alternatives, implementation of requirements, and the ultimate transition by 2030, except in Alaska (which would follow in 2032). The agency notes that since the rollout is widely dependent on the market, the plan may evolve.

Under the first phase to be completed by mid-2027, the agency, in concert with industry, would approve the unleaded replacement fuels and assess how they compare. Three candidates are currently under evaluation, with some further along than others. These include the GAMI G100UL, which is already widely approved for piston aircraft and is in limited distribution. This fuel was developed using an independent specification.

Swift Fuels’ 100R is also under consideration. This fuel has received initial approval and is in use at five flight schools in California, Missouri, and Illinois. Swift has initially worked to replace UL94 with a replacement for higher-horsepower and turbocharged aircraft, anticipated by the end of the year. The company is working toward an ASTM specification.

Also working with ASTM on a broad specification for its fuel is LyondellBasell/VP Racing with the UL100E. This fuel has received the initial test specification approval, with full-scale testing planned for later this year and fleet approval by mid-2027.

After evaluating and comparing the fuels, the second phase would then focus on gaining market experience with the fuels. This will provide lessons learned on the market and integration, the FAA said, considering potential barriers of fuel mixing, storage requirements, fuel composition, and continuity, as well as compatibility, logistics, price, and liability. Fuel production would scale at this point in anticipation of a full national rollout.

In phase three, all airports outside Alaska would eliminate leaded fuel, switching to unleaded options, and then the final phase would roll out unleaded fuels in Alaska. The FAA noted that Alaska faces unique challenges requiring more time.

The National Air Transportation Association (NATA) welcomed the framework and advised its members to review and comment on the plan to ensure they can help shape the transition. “The FAA emphasizes that stakeholder input will further inform the plan and help keep safety at the forefront,” NATA noted.