The United States Air Force (USAF) is committed to positioning itself to integrate cost competitive alternative aviation fuels for up to half of its domestic needs by 2016. Working with the Air Force Research Laboratories, the Air Force Alternative Fuels Certification Division (AFCD), and the 40 Flight-Test Squadron, Gevo provided fuel for the first successful alcohol-to-jet (ATJ) fuel test flight.
In June 2012, the United States Air Force flew an A-10 Thunder Bolt jet aircraft powered by a Gevo-produced blend of 50 percent ATJ fuel and 50 percent JP-8 (the traditional MILSPEC jet fuel). 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.
“The AF previously ran a series of engine ground tests, using the 50/50 blend of the ATJ and JP-8,” says 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 USAF contracted Gevo in 2011 to provide 11,000 gallons of its isobutanol-derived ATJ fuel for testing by the AFCD. In October 2012, Gevo was awarded a second order for 45,000 gallons. 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.
“We’re extremely proud to have contributed to the USAF’s first ATJ test flight,” says Christopher Ryan, Ph.D., President, COO, and CTO of Gevo. “The 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.”