Unleaded Avgas on Track to Be at California Airports by Summer 2023

by Tom Snow (General Aviation News) Unleaded 100-octane aviation fuel should be available at three California airports as early as this summer, according to officials with General Aviation Modifications Inc. (GAMI).

In an hour-long, standing-room-only forum at the 2023 SUN ‘n FUN Aerospace Expo presented by GAMI’s George Braly, he noted that — if all goes according to plan — Reid-Hillview Airport of Santa Clara County (KRHV), Watsonville Municipal Airport (KWVI), and Meadows Field Airport (KBFL) in Bakersfield will be the first airports in the country to offer GAMI’s lead-free 100 octane FAA-approved avgas known as G100UL.

A California FBO chain also has expressed interest in distributing the new fuel at its 13 locations, he noted.

“California is crying for this fuel,” said Braly. “The avgas situation at the Reid-Hillview airport is critical because the sale of 100LL has already been suspended there.”

As a sad result, Braly said that a plane reportedly ran out of fuel and crashed when its owner attempted to fly from Reid-Hillview to a nearby airport for a fill-up. The plane’s fuel had been depleted by extended engine run-ups at a maintenance shop.

After a 13-year effort and many roadblocks, GAMI finally received its all-inclusive STC in September 2022. During the SUN ‘n FUN forum, Braly praised the efforts of the FAA certification staff in the Wichita office. He also cited help at critical junctures from now retired Senator James Inhofe and Mark Baker, president of the Aircraft Owners and Pilots Association (AOPA).

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In order to buy and use the new environmentally friendly fuel which, appropriately enough, is green in color, aircraft owners are required to purchase an STC from GAMI. The STC costs around $2 per horsepower and includes placards and a flight manual supplement.

As a drop-in fleet-wide avgas replacement, G100UL can be mixed with 100LL in any ratio and without any alteration to aircraft engines or airframes, GAMI officials added.

GAMI is currently working with an experienced aviation fuel blender in Houston that can produce the patented formulation in railcar quantities by the end of June 2023. After the shipment of G100UL arrives in California, the fuel will be loaded into tanker trucks and delivered to individual airports.

Avfuel, a global supplier of aviation fuel, helped GAMI fund the STC process over the past six years, but any qualified aviation fuel producer or blender can apply for a license to produce and distribute G100UL.

“That creates competition,” said Braly, who hopes to have nationwide distribution in place by 2026. “It’s a chicken and egg situation.”

The new avgas has been thoroughly tested since 2010, when it was first flown in GAMI’s turbo-normalized Cirrus SR-22. In addition, Braly reported that the Cirrus Aircraft factory in Duluth, Minnesota, conducted a series of independent and well-documented test flights last winter that compared and graphed the differences between 100LL and G100UL.

Braly reported that Cirrus confirmed his earlier experiments showing that GAMI’s unleaded avgas produces a 4% improvement in Brake Horsepower (BHp) at the same lean of peak (LOP) fuel flow. In the example cited, G100UL produced almost 10 horsepower more than 100LL.

“The science works folks,” said Braly. “The tests done by Cirrus were an elegant experimental ratification of earlier test data.”

Braly was also quick to point out that having more energy available from G100UL makes up for the fact that it weighs slightly more than 100LL and is likely to cost more.

During testing observed by FAA officials, detonation protection from using G100UL exceeded that of 100LL, Braly reported.

In addition, Embry-Riddle Aeronautical University helped GAMI conduct a successful 200-hour engine durability test using a relatively high time (1,400 hours) engine. Robinson Helicopter is also about to start its own independent evaluation of G100UL.

Other tests have shown that GAMI’s avgas does not harm fuel tanks made of fiberglass and carbon fiber. Also, a batch of G100UL that had been stored in a drum for 12 years still met specifications, Braly noted.

Other unleaded 100 octane aviation fuels are in the testing process, including those from Swift Fuels, Lyondell and VP Racing, and Phillips 66 and Afton Chemical.

You can learn more about G100UL at G100UL.com. You can learn more about the FAA’s unleaded fuel initiatives at FAA.gov/Unleaded. READ MORE