May 14, 2014
By Jim Moore
In simplest terms, the international research collaboration launched this month is dedicated to sniffing jet exhaust at altitude. For the pilots, it is a challenging assignment: Deliberately probing exhaust plumes, contrails, and wake vortices at altitude, trailing a NASA DC-8 at distances ranging from a little over 300 feet up to 11 nautical miles.
Wake turbulence is certainly a factor.
The airborne emissions test is being conducted under a collaboration between NASA, the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt, or DLR) and the Canadian National Research Council, which operates a T-33 flown specifically to explore the DC-8’s wake turbulence dynamics, while a Falcon jet operated by DLR focuses on collecting air samples. The project will compare the emissions produced by burning standard fuels against various biofuel blends, to better understand the exact nature of biofuel emissions.
“Our Falcon is an extraordinarily robust research aircraft and ideal for taking measurements in the exhaust plume and in condensation trails," said DLR test pilot Philipp Weber, in a news release. "Heavy structure loads that not all aircraft are designed for can occur in aircraft wake turbulence."
The subtext: Don’t try this at home.
The collaboration between NASA and DRL dates back more than 15 years, and the latest round of test flights is comparing straight JP-8 emissions to a one-to-one mixture with biofuel derived from the oil of Camelina plants, a weed also known as “false flax” that has long been cultivated for its oil. Researchers expect the blend to reduce the sulfur content of jet exhaust, reducing soot emissions that may also lead to larger ice crystals in the condensation trail.
AOPA Online Associate Editor Jim Moore joined AOPA in 2011 and is an instrument-rated private pilot who enjoys competition aerobatics.
Aircraft Power and Fuel,
R and D,
Two bills that would increase aviation fuel taxes and tap some proceeds for nonaviation purposes could place New Mexico in conflict with federal grant guarantees.
An online video service launched to give enthusiasts an aerobatic ride-along from multiple camera perspectives is expanding into a more interactive experience.
Avoid leaning the fuel-air mixture so much that engine heat becomes excessive.
VOLUNTEER AT AN AOPA FLY-IN NEAR YOU!
SHARE YOUR PASSION. VOLUNTEER AT AN AOPA FLY-IN. CLICK TO LEARN MORE >>>
VOLUNTEER LOCALLY AT AOPA FLY-IN! CLICK TO LEARN MORE >>>
BE A PART OF THE FLY-IN VOLUNTEER CREW! CLICK TO LEARN MORE >>>