Researchers at the US National Aeronautics and Space Administration (NASA) have initiated a series of flights under the Alternative Fuel Effects on Contrails and Cruise Emissions (ACCESS) program.
Using the agency’s DC-8 flying laboratory, the research aims to study the effects of alternate biofuel on engine performance, emissions and aircraft-generated contrails at altitude.
As part of the research, an instrumented NASA Falcon HU-25 aircraft will trial the DC-8, as it flies at a maximum altitude of 40,000ft.
The four CFM56 engines of the DC-8 will run on conventional JP-8 jet fuel, or a 50-50 blend of JP-8 and an alternative fuel of hydroprocessed esters and fatty acids sourced from camelina during the flights.
The Falcon will trail behind the DC-8 at distances ranging from 300ft to over 10 miles.
Several instruments mounted on the Falcon jet will monitor the interaction of exhaust plumes with air, characterize the soot and gases streaming from the DC-8 and examine the role emissions play in contrail formation.
NASA’s Fixed Wing Project manager Ruben Rosario said, "We believe this study will improve understanding of contrails formation and quantify potential benefits of renewable alternate fuels in terms of aviation’s impact on the environment."
ACCESS flight operations will be undertaken from NASA’s Dryden Aircraft Operations Facility in Palmdale, California, within restricted airspace over Edwards Air Force Base.
The flight campaign is expected to complete after three weeks, while a second phase of ACCESS flights will commence in 2014.
Tests will derive on information from the 2013 flights and include a more extensive set of measurements.