The FAA signed off on supplemental type certificates to allow General Aviation Modifications Inc.’s 100-octane unleaded fuel (G100UL) to be used in every general sparkignition engine and every airframe powered by those engines. The move was hailed by the GA industry as a major step in the transition to an unleaded future.

The FAA’s approval of the use of G100UL fuel in all piston aircraft directly addresses the industry’s longstanding goal of finding unleaded solutions that can be used for the entire GA piston fleet.

“This is an outstanding first step in protecting our environment and allowing piston-powered helicopters to fly safely and cleanly,” says James Viola, President and CEO of Helicopter Association International (HAI). “Along with the other general aviation associations, we deeply appreciate the efforts of GAMI and the FAA in producing this fuel and STC. As an owner of a piston-powered helicopter, I think I speak for everyone when I say that I can’t wait to fill my tank with this unleaded fuel for the first time.”

“I’m proud of GAMI, the industry team, and the FAA for persevering over the long term and getting a fuel that the FAA has recognized as a viable alternative to low lead,” AOPA President Mark Baker said. “It’s vital that we find solutions to what has been plaguing general aviation since the seventies. It’s certainly the biggest issue I have dealt with in my time at AOPA.”

“This is a big deal,” Baker added, “but there is a lot of work yet to be done.”

In 2021 the FAA approved STCs for GAMI covering a smaller number of Cessna 172 engines and airframes, and then expanded those STC approved model list (AML) to include essentially all lower-compression engines. Though that was seen as an encouraging step forward in the years-long path to supply unleaded aviation fuel to the piston aircraft fleet, the STC’s did not include aircraft needing the higher-octane fuel that accounts for approximately two-thirds of avgas consumption. Today’s announcement by the FAA addresses the needs of those higher-compression engines.

GAMI co-founder George Braly said, “This is a big day for the industry. It means that for a lot of our general aviation communities, and especially for a high fraction on the West Coast, relief is on the way. And it means that our industry will be able to go into the future and prosper, and provide the essential infrastructure for this country for everything from Angel Flights to critical training of our future airline pilots.”

Braly thanked the GA community for its support through this long process. “Without it we couldn’t have gotten this done,” he said.

GAMI’s Braly has said that Ann Arbor, Michigan-based fuel supplier Avfuel is standing by to manage the logistics and distribution of G100UL, and said he is open to partnerships. “Our arrangement is that any qualified refiner or blender of existing aviation fuels will be eligible to produce and sell it subject to the quality assurance requirements that the FAA has approved,” he said.

The timing for when G100UL will reach airports is still uncertain. “It’s going to take a while to manage the infrastructure including manufacturing and distribution,” Braly said. The supply chain “is still a very wounded infrastructure and that’s not going to make the process any easier, but we have a handle on how to do this, and with the support of the major players I think we can do that. It’s going to be limited to begin with, but it can be ramped up rapidly,” he said.

Swift Fuels Inc., an Indiana based company, has received FAA approval for its 94-octane unleaded fuel, and has expanded its distribution, particularly to the West Coast. Swift Fuels’ 94-octane fuel meets some, but not all, of the demand of aircraft with lower-compression engines. The company is developing a 100R unleaded fuel with more than 10 percent renewable content.

In addition, two fuel candidates are currently in the PAFI testing process.

All fuel manufacturers continue to be encouraged to follow through with their own formulations, Baker said. “We’d like to see several fuels available that all work together and blend together. Competition is always a good thing for the markets.”