Since the US Air Force is the single largest user of aviation fuel within the federal government - burning about 3 billion gallons per year, they continue to look hard at ways to save gas. One area of research is synthetic fuel.

The USAF first flew a B-52 Stratofortress on a 50/50 blend of synthetic and petroleum fuel back in August. A C-17 Globemaster flew with the fuel in October (captured on this Aviation Week video).

Next up is the first supersonic flight using 50/50 fuel, scheduled for a B-1 Bomber March 19.

The B-1 from Dyess Air Force Base in Texas will take off from its home, but the supersonic portion of the flight will take place over White Sands Missile Range in New Mexico.

Credit: USAF