The engine that powers Cessna's CJ series, Hawker Beechcraft's Premier and others has just demonstrated its ability to run on "coal-based alternative fuel," according to Williams International. The Williams FJ44-3 test article burned 2,000 gallons of the fuel-developed at Penn State University. It performed "extremely well," exhibiting performance numbers on par with the jet-A powered version of the same engine. And the test engine required no modifications as part of the 21-hour, 118-cycle test program. The coal-based fuel was reported as essentially free of sulfur and nitrogen; but exhibited energy density that is higher than that of conventional jet-A. That could translate into longer range using the same amount of fuel.