Unleaded Avgas: Still More Confusion

EAGLE’S most recent public information letter discusses the FAA Fleet Authorization process. However, what it doesn’t say is concerning.

avgas fueling 100LL

Near the end of February 2025, the FAA/industry coalition Eliminate Aviation Gasoline Lead Emissions (EAGLE) issued Part 2 of its series entitled “Clearing the Air: How Unleaded Aviation Fuel Is Gaining Approval.” This part focused on the FAA Fleet Authorization process. It is on the EAGLE website at flyeagle.org/updates.

EAGLE’s Part 1 covered the STC process, with Part 3 to come next month to discuss the “critical role” of industry consensus standards, the process of fuel approval via an ASTM spec and FAA approval. We note right here that while EAGLE has been ostensibly neutral when it talks about the routes to FAA approval of an avgas—STC, PAFI (Piston Engine Fuel Initiative) fleet authorization and ASTM/FAA routes—we feel that it has failed in its duty to be neutral. Part 2 is consistent with its past behavior actively or passively denigrating the STC approval route. This is not surprising as EAGLE was organized to only support the ASTM and Fleet Authorization route and not the more rigorous FAA STC fuel approval method—even though it is an FAA organization.

Rick Durden

Senior Editor Rick Durden has written for Aviation Consumer since 1994 and specializes in aviation law. Rick is an active CFII and holds an ATP with type ratings in the Douglas DC-3 and Cessna Citation. He is the author of The Thinking Pilot’s Flight Manual or, How to Survive Flying Little Airplanes and Have a Ball Doing It, Vols. 1 & 2.