National Aeronautics and Space Administration (NASA) researchers recently concluded a series of test flights in California to study the effects of alternate biofuel on “engine performance, emissions and aircraft-generated contrails at altitudes typically flown by commercial airliners.”
According to a NASA news release, the experiment involved flying a DC-8 airplane as high as 39,000 feet while an instrumented HU-25C Guardian aircraft followed at distances ranging from 300 feet to more than 10 miles measuring “exhaust composition and contrail characteristics depending on fuel type, plume duration and atmospheric conditions.” During the flights, the plane’s four engines were powered by “conventional JP-8 jet fuel, or a 50-50 blend of JP-8 and an alternative fuel of hydroprocessed esters and fatty acids produced from camelina plant oil.”
The researchers reportedly found that (i) the camelina mixture burned cleaner than standard fuel; (ii) the pilots reported no difference in the plane’s performance; and (iii) the pilots noticed a greater improvement in emissions—particularly in soot reduction—when the plane was idling on the ground. Senior research scientist Bruce Anderson from NASA’s Langley Research center said, “Producing biofuels for aircraft is still an evolving technology, and for now labor-intensive and thus more costly. Camelina biofuel, for instance, cost about $18 a gallon, while regular fuel runs about $4 a gallon.”
NASA will share this research with aircraft manufacturers and plans another phase of its Alternative Fuel Effects on Contrails and Cruise Emissions experiments next year. See NASA News Release, April 23, 2013; Dailypress.com, April 25, 2013.