The Air Force made progress in its quest for alternative fuels Thursday when it flew an A-10 Thunderbolt II with 100 percent biomass fuel, called hydrotreated renewable jet (HRJ) fuel.
The fuel used for the flight was made of camelina plants and was engineered to run without modifying the aircraft's engine -- a key to any alternative fuel the Air Force would agree to use.
Maj. Chris Seager, a test pilot with the 46th Test Wing's 40th Flight Test Squadron, said his historic flight was exactly what he had hoped: boring.
"It's a good flight if it's a boring flight," Seager said. "It was an uneventful sortie, which means it was a very good sortie. Things went well."
The Air Force has been looking at alternative fuels for quite awhile, said Tim Edwards, senior chemical engineer with the Air Force Research Laboratory.
The effort kicked into high gear in 2006, when then-Secretary of the Air Force Michael Wynne started pushing for quick answers to the rising cost of jet fuel.
Edwards and his colleagues went from testing a few gallons of biofuels at a time to buying hundreds of thousands of gallons a year.
"This is the first step in a much broader effort," said Jeff Braun, director of the Air Force's Alternative Fuels Certification Office.
The Air Force is the largest consumer of jet fuel in the Department of Defense. It has set a goal to replace half of its continental U.S. jet fuel requirement (about 400 million gallons) with alternative fuels that are cost-competitive and more environmentally friendly than traditional fossil fuels.
The Air Force Research Lab tests every "wet fuel" part of a plane with the alternative fuel before it starts testing it on planes themselves. The A-10 Warthog was the first to be tested.
Researchers started this week by running the fuel in the aircraft without flying, and quickly moved on to running one engine with the HRJ and the other with the traditional H8 fuel. Thursday's test flight was the first sortie with 100 percent HRJ.
The next step is to start the process over with another aircraft. Testing for the F-15 will start in a few months. The F-22 and the C-17 are next in line.
If all of the test flights are "boring," Braun's office will certify that the fuel can be used for the military.
The plan is to certify the biomass fuel by 2012 and have it in use by 2016.
"You have to create the demand to get the supply," said Beatriz Rodriguez, chief engineer for the Air Force Alternative Fuels Certification Office.
Once the fuel is certified, companies are expected to start producing the crude plant fuel so oil refineries can turn it into something the military can buy.
The Air Force consumes about 2.4 billion gallons of fuel a year, the equivalent of a small commercial airline, Edwards said.
As a large consumer of jet fuel, officials say the demand will make biofuel production a competitive industry and a cost-efficient product. Manufacturing plants for the alternative fuel already are being built in Louisiana and Washington.
"We'll be ready to use it when they're ready to deliver it," said Terry Yonkers, assistant secretary of the Air Force for Installations, Environment and Logistics.
Edwards said the goal is to certify several alternative fuels and eliminate a dependence on foreign oil. Researchers are looking at alternative fuels produced from animal fat and other plants.
Last year, the military certified the use of JP-8 jet fuel that was a 50/50 mix of biofuel. A biofuel produced in South Africa from coal and natural gas also was certified for Air Force use.