[ Read the Article: NASA’s ACCESS II Alternative Jet Fuel Flight Tests Begin Today ]
This video was taken from a NASA HU-25C Guardian chase plane looking toward NASA’s DC-8, with a Falcon 20-E5 from the German Aerospace Agency (DLR) soon to fly into the DC-8′s exhaust. The Falcon is testing how it maneuvers in the contrail and the performance of onboard instruments it’ll use to sample exhaust and ice particles. The trip was one of several test-plan verification flights done on May 7, 2014, to prep for the next day’s start of the ACCESS II campaign to test emissions from the DC-8 using biofuel.
The condensation trail (or contrail) forms when water vapor from the engine exhaust condenses on the engine soot particle emissions; similar to the visible exhaust from a truck or automobile tail pipe on a cold day. Aircraft engines always emit exhaust particles and gases, but they’re not visible unless the atmosphere is sufficiently cold and moist enough to condense water onto these particles.
Within NASA, ACCESS II is a joint project involving researchers at Armstrong, Calif.; Langley, Va.; and the Glenn Research Center in Cleveland. The research supports NASA aeronautics’ strategic vision, which has as a goal to enable transition of industry to low-carbon fuels and alternative propulsion systems.