The jet flew at a variety of flight conditions, achieved supersonic speeds, and landed with no issues, though it was powered with a hydro-processed renewable jet blend fuel Oct. 22 according to the U.S. Air Force Alternative Fuels Certification Office.
"The flight went as expected; we didn't anticipate any issues going into it," said Maj. Matthew Coldsnow, the 40th Flight Test Squadron pilot who flew the first F-15 flight using something other than the common kerosene-based jet propellant 8 fuel. "The chemical properties are very similar to that of normal fuel. I didn't notice any change in thrust or performance degradation."
The biofuel blend used for the flight was composed of 50 percent HRJ mixed with 50 percent JP-8. The HRJ used for this evaluation was derived from extracted animal fats and oils, and then refined into a kerosene using conventional processes. In March, an A-10 Thunderbolt II flew on a 50/50 JP-8/HRJ blend derived from oil extracted from camelina seeds, a weed-like, non-food-source plant.
"Alternative fuels testing allows the Air Force to look at alternative fuels from non-petroleum sources, an effort that kicked off in 2006," said 1st Lt. Luke Gaalswyk, with the Alternative Fuels Certification Office. "The larger picture of using these fuels is that it allows the Air Force to purchase more fuel from inside our borders, in turn reducing our dependence on foreign oil."
Air Force officials are embracing national priorities of cleaner fuel and energy independence.
"The Air Force is working toward an ambitious goal of changing half of the continental U.S. jet fuel requirement to alternative fuels by 2016," said Air Force Material Command Commander Gen. Donald J. Hoffman.
This could represent as much as 400 millions gallons of fuel annually.
President Barack Obama acknowledged the military's leadership in nurturing development of renewable biofuels during a speech at Andrews Air Force Base just days after the A-10 test flight, the Air Force's successful first flight of an aircraft on all engines burning a biofuel.
"It's always a neat experience to be the first person to do anything," said Major Coldsnow. "We've taken a step in the right direction."
During the test, the pilot took off in afterburner and explored a variety of speeds and altitudes while remaining within the aircraft's approved flight envelope.
"The next step is additional flight and engine testing to build on data we have with a high level of confidence that we can certify this fuel for operational use in operational aircraft," Lieutenant Gaalswyk said.
"The Air Force is committed to reducing our reliance on foreign oil," said Terry Yonkers, the assistant secretary of the Air Force for installations, environment and logistics. "Our goal is to reduce demand, increase supply and change the culture and mindset of our fuel consumption."
The Air Force is the largest user of jet fuel in DOD, consuming 2.4 billion gallons per year.
A short-term goal is to have all Air Force aircraft certified to fly using alternative fuels by 2012, said Mr. Yonkers.
"To truly transform our economy, protect our security, and save our planet from the ravages of climate change, we need to ultimately make clean, renewable energy the profitable kind of energy," said President Obama during his speech in April.