Long-Term Unleaded Fuel Test Begins in AOPA Baron

AOPA began flight testing in its AOPA Baron of unleaded, high-octane avgas. The project launched this week with the introduction of GAMI’s G100UL during initial flights in Oklahoma.

The flight testing will take place in a Beechcraft Baron donated by AOPA members Greg Herrick and Dan Shewmaker. [Courtesy: AOPA/David Tulis]

Seeking to understand for its membership the long-term effects of various new fuels on the general aviation market, the Aircraft Owners and Pilots Association has begun flight testing unleaded, high-octane avgas in a Beechcraft Baron. 

The project launched this week with the introduction of GAMI’s G100UL during initial flights in Ada, Oklahoma. Beginning with a baseline of two freshly overhauled Continental IO-520 engines, the Baron will be operated under AOPA management, with the cooperation of Savvy Maintenance founder and technician guru Mike Busch, using the company’s computerized diagnostic tools to analyze engine data and compare it against the information it has collected from “hundreds of thousands of hours of GA flights,” according to an AOPA release.

An AOPA spokesperson told FLYING that the association is staging in Ada right now “since that is where the majority of the fuel is, and it makes sense to use [it] as a geographically appealing hub.” Presumably this will allow AOPA the “best efficiency in demonstrating the fuel to a wide range of people.” GAMI’s fuel obtained a supplemental type certificate, covering a broad range of piston aircraft, from the FAA in September 2022. The initial STC for Lycoming O-320, O-360, and IO-360 engines came in July 2021. 

AOPA president Mark Baker was at the controls for the demonstration flight to kick off the program on October 31. For one hour, Baker flew with G100UL feeding the left engine and standard 100LL powering the right one.

“We wanted to get some actual experience with a 100-octane unleaded fuel in the kinds of airplanes and engines that our members own and fly,” said Baker. “This fuel has been tested extensively in labs and received an FAA STC. Should the FAA approve additional fuels, we’ll test them, too, so we can see what they’re like to use out on the airways.

“George Braly and GAMI have done a great deal of pioneering work preparing for general aviation’s unleaded future. We’re staging the AOPA Baron at GAMI’s headquarters in Ada first to try out its G100UL.”

Julie Boatman
Julie BoatmanContributor
Based in Maryland, Julie Boatman is an aviation educator and author. She holds an airline transport pilot certificate with Douglas DC-3 and CE510 (Citation Mustang) type ratings. She's a CFI/CFII since 1993, specializing in advanced aircraft and flight instructor development.

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