Air Force Research Laboratories Test A-10 Thunder Bolt Jet Aircraft With Alcohol Fuel

  • Author: Rebbeca Espinossa-Fulgham
  • at 2:19 PM -

Air Force Research Laboratories Test A-10 Thunder Bolt Jet Aircraft With Alcohol Fuel

Recently, the Air Force Alternative Fuels Certification Division the USAF A10, in cooperation with Gevo, Inc. conducted a successful test flight powered by Gevo’s Alcohol-to-Jet fuel and thus validates its military application. Gevo, Inc. is a leading renewable chemicals and next-generation biofuels company, which was contracted last year to provide the USAF 11,000 gallons of its ATJ fuel derived from isobutanol alcohol for testing by the AFCD. Gevo’s patented ATJ fuel is touted as a “drop-in fuel”, and said to have been deliberately designed to be fully compliant with aviation fuel specifications and provide equal performance, including fit-for-purpose properties.

Air Force Research Laboratories Test A-10 Thunder Bolt Jet Aircraft With Alcohol Fuel

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. 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. A series of flight test maneuvers, throttle bodies, auxiliary power unit (APU) starts and engine assisted starts were performed. A Honeywell 36-50 APU was used for engine starting and in flight emergency power generation.

Statements from Gevo President Chris Ryan:

“We’re extremely proud to have witnessed and contributed to the USAF’s first and only ATJ test flight,” “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,”

 “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.”

Statements from A-10 test engineer, Joseph Rojas:

“The A-10 serves as an excellent platform for testing the new fuel, as it features a segregated fuel system. This allows us to fly with one engine on the new fuel and the other on traditional fuel. If engine operation is normal, as with the ATJ blend, then we progress to flying with both engines on the new fuel.”

Following the completion of all air and ground testing, the ATJ is scheduled to be approved as an official alternative fuel source for the USAF.

The ATJ is a cellulose-based aviation fuel obtained through fermentation and hydro-processing of sugars derived from wood, paper, grass, as well other cellulose materials, and is the third alternative fuel to be evaluated by the service after a Fischer-Tropsch synthetic paraffinic kerosene (SPK) and a bio-mass fuel. According to USAF, the SPK is derived from coal and natural gas, while the bio-mass fuel is obtained from plant-oils and animal fats called hydro-processed renewable jet (HRJ).

The service has already certified the SPK blend for operational use on the aircraft, and also completed testing of the bio-mass HRJ in 2010, and is conducting a formal coordination for certification as an approved fuel agent.

This is certainly exciting news, and deserves a smart salute from all of us at the Grantham University Fan Club!


Written by

Becky works in the health sciences industry and spends most of her professional work day in the research and development laboratory working on applied solutions for health and wellness. Becky is an avant supporter of her alma mater Grantham University. In her free time she writes articles for the Grantham University Fan Club site and volunteers at the local Chicago suburb elementary school where her children attend. Her motto is, “Changing the world, one smile at a time!”


  1. Are there any updates as far as how they are doing with this project?

  2. David, Sorry it took me so long to respond to your question as to updates on our Gevo article.

    But trust me, this update is worth the wait! There are some amazing developments to share!

    In October 2012, Gevo:

    1. Was informed that it was awarded a follow-on biojet fuel order from the Defense Logistics Agency. This order follows the U.S. Air Force's successful test flight conducted in June using Gevo's Alcohol-to-Jet (ATJ8) fuel. The order is for 45,000 gallons of ATJ8 to be delivered in two tranches during 2013 and will be used for additional U.S. Air Force testing purposes.

    2. Signed a letter of intent with Midwest AgEnergy Group, LLC (MAG) to jointly evaluate the technical and economic considerations of retrofitting one or more MAG ethanol biorefineries to manufacture isobutanol. MAG is a biofuels development affiliate of Great River Energy, a Minnesota electric cooperative serving over 1.7 million customers. MAG will own Blue Flint Ethanol LLC (an operational 65 MGPY ethanol biorefinery based in North Dakota) and Dakota Spirit AgEnergy, LLC (a planned 65 MGPY ethanol biorefinery based in North Dakota). "Gevo has submitted a lifecycle analysis to the EPA to qualify corn based isobutanol as an advanced biofuel under RFS2 when it has a greenhouse gas footprint of less than 50% of gasoline and we see Midwest AgEnergy's unique assets as one potential pathway to produce advanced isobutanol," commented Dr. Gruber. "Isobutanol potentially provides an opportunity to further maximize the value of our facilities by making them capable of producing multiple market, potentially higher value fuels and chemicals. Based on our diligence to date and the relationship that has been developed over the last year, Gevo is our preferred partner for providing isobutanol production technology to retrofit the MAG biorefineries," stated Greg Ridderbusch, President, Midwest AgEnergy Group.

    3. Was awarded U.S Patent No. 8,283,505 (the '505 Patent) which protects Gevo's Integrated Fermentation Technology®. The technology covered by the '505 Patent protects what we believe to be the most cost-efficient separation technology available. The USPTO granted the '505 Patent in view of art cited against Gevo's earlier issued U.S. Patent No. 8,101,808 in a reexamination request filed by Butamax Advanced Biofuels, LLC (Butamax); and U.S. Patent No. 8,273,565 entitled "Methods of Increasing Dihydroxy Acid Dehydratase Activity to Improve Production of Fuels, Chemicals, and Amino Acids." The patent covers the suppression of a glutaredoxin protein called GRX3. In combination with other Gevo patented technologies, deletion of GRX3 significantly increases the production of isobutanol by yeast cells.

    For more info, please go to:

    I am not associated with the company, but their technology interests me greatly. I hope this helps.