WASHINGTON, D.C. — The Federal Aviation Administration (FAA) has published a long-anticipated draft Transition Plan to Unleaded Aviation Gasoline, outlining how the U.S. general aviation fleet of piston-engine aircraft could move away from 100-octane low-lead (100LL) avgas and toward unleaded alternatives by the end of the decade. The draft — issued in January 2026 and now open for public comment — represents a significant step in phasing out the last remaining leaded fuel used in transportation.
Why This Matters
Unlike automotive fuel, most general aviation aircraft still rely on leaded avgas to achieve necessary octane levels for engine performance and safety. Lead additives help prevent engine knock at high power settings, but lead emissions have long been recognized as a public health concern, especially for communities near airports.
Under congressional direction from the 2024 FAA Reauthorization Act, Section 827, the FAA is required to develop a transition plan to eliminate leaded aviation fuel use without adversely impacting the safety or operational efficiency of the existing general aviation fleet.
A Phased National Framework
Rather than imposing a single fuel solution or strict deadlines for individual airports, the draft plan outlines a four-phase framework designed to allow market forces, fuel development, and safety data to guide the transition:
- Fuel Authorization and Comparison: Identify and compare candidate unleaded fuels that have secured FAA approvals or authorizations, and assess performance, compatibility, and safety across a range of aircraft.
- Market Experience: Encourage real-world use of approved fuels at airports, allowing pilots and operators to gather operational insights and infrastructure needs.
- National Transition (Contiguous U.S.): Facilitate widescale adoption of unleaded avgas, with the goal of phasing out 100LL across most of the country by 2030.
- Alaska Transition Phase: Recognize Alaska’s unique logistical challenges by extending its transition timeline to 2032.
No Mandated Fuel — Yet
The FAA’s draft does not identify a single replacement fuel to supplant 100LL. Instead, it anticipates that multiple unleaded fuels could gain acceptance through different approval pathways, including standard certification processes and broader “fleet authorizations” that would apply to many aircraft types at once.
The approach supports options such as GAMI’s G100UL, Swift Fuels’ 100R, and UL100E from LyondellBasell/VP Racing, each at various stages of evaluation or certification. However, no candidate has yet achieved widespread commercial availability or full authorizations to meet all operational needs across the fleet.
Safety, Infrastructure, and Stakeholder Input
The draft emphasizes that safety remains paramount and that a structured transition must consider fuel handling infrastructure, airport storage and dispensing readiness, supply chain logistics, and labeling to prevent misfueling.
To refine the plan, the FAA is soliciting public comments from pilots, aircraft owners, airports, fuel providers, and industry stakeholders through March 13, 2026. Feedback will help shape the final strategy and highlight operational or economic considerations from those most affected by the transition.
Industry and Community Response
General aviation organizations — including the National Air Transportation Association (NATA) and the Eliminate Aviation Gasoline Lead Emissions (EAGLE) initiative — have welcomed the draft framework but also stressed the importance of meaningful industry input to ensure the transition remains safe, practical, and aligned with real-world needs.
AOPA and other pilot advocacy groups are also actively encouraging members to review the draft and submit comments, reinforcing that the plan is not yet a regulation and could evolve significantly based on community feedback.
Looking Ahead
If finalized, the FAA’s Transition Plan to Unleaded Aviation Gasoline could reshape the future of piston-engine aviation, balancing environmental health goals with operational realities. The timeline to phase out leaded avgas in the contiguous U.S. by 2030 — and in Alaska by 2032 — sets ambitious targets that will require coordinated action among regulators, fuel developers, airports, aircraft owners, and the broader aviation community.
