Gevo, working with the Air Force Research Laboratories (AFRL), the Air Force Alternative Fuels Certification Division (AFCD) and the 40 Flight-Test Squadron, provided fuel for the first successful "alcohol-to-jet" (ATJ) fuel test flight, the company announced.

At 18:30 hours, on June 28, the USAF flew an A-10 Thunder Bolt jet aircraft powered by a Gevo-produced blend of 50% ATJ fuel and 50% JP-8. A series of flight test maneuvers, throttle bodies, auxiliary power unit (APU) starts and engine assisted starts were performed. The A-10 is a single-seat aircraft powered by two high-bypass GE TF34 turbofan engines. A Honeywell 36-50 APU is used for engine starting and in flight emergency power generation.

"We're extremely proud to have witnessed and contributed to the USAF's first and only ATJ test flight," said Chief Operating Office and President Chris Ryan. "Last week's test flight represented an accumulation of more than 4,000 hours of hard work involving innovative testing, multiple players and years of research on everyone's part. Together, we have proven that ATJ fuel is a technically viable and promising alternative for both military and commercial applications."

"This is a great accomplishment for the USAF, Gevo and the biofuels industry. We've validated that ATJ from isobutanol is a clean burning, homegrown, drop-in jet fuel. The USAF's flight has taken the industry one step closer to full commercialization. We remain committed to commercialization and believe we have the most economic route to deliver aviation biofuels at scale," Ryan said.

Gevo, a leading renewable chemicals and next-generation biofuels company, was put on contract last year to provide the USAF 11,000 gallons of its ATJ fuel derived from isobutanol for testing by the AFCD. Gevo's patented ATJ fuel is truly a drop-in fuel, deliberately designed to be fully compliant with aviation fuel specifications and provide equal performance, including fit-for-purpose properties.

"The AF previously ran a series of engine ground tests, using the 50/50 blend of the ATJ and JP-8," said Jeffrey Braun, Division Chief of AFCD. "Data was then compared with previous results from JP-8 baseline testing. Engine performance parameters monitored during the testing remained unchanged when utilizing the ATJ fuel blend. We were very pleased with the technical performance of the ATJ material."

The A-10 Thunderbolt II is a single-seat, twin-engine, straight-wing jet aircraft originally developed by Fairchild-Republic. The A-10 is a Close Air Support (CAS) platform, providing support to ground forces by attacking tanks, armored vehicles, and other ground targets with a limited air interdiction capability.