By Dan Catchpole

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Nov. 2, 2023 © Leeham News: High over Montana, Andy “Jeeves” Barry slipped the McDonnell Douglas DC-8 to the right and out of the Boeing 737-10’s wake to “get some fresh air.”

NASA's uses a highly-modified McDonnell Douglas DC-8 as a test platform for its Armstrong Flight Research Center. (Photo by Dan Catchpole)

After a few minutes, the NASA research pilot edged the DC-8 behind the MAX, trailing about a mile and a half or so. It was another in a slew of test flights in October that he’d spent riding the 737’s bumper in NASA’s venerable DC-8 research aircraft.

The former U.S. Navy aviator eased the workhorse into a slot of calmer air in the 737’s wake, he said. “…[I]n that sweet spot of that secondary (wake) and just above the primary wake is where we lived the whole time and got the best science that they really loved the entire time we were out there.”

NASA and Boeing collaborated on the flights to test the effect of sustainable aviation fuels (SAF) on the formation of contrails, short for condensation trails, which climatologists contribute to global warming. The 737-10 alternated between burning jet fuel and 100% SAF, while the DC-8 sampled the air in its wake.

Summary

• Researchers say data collected will help predict when and how contrails form and SAF’s effects on contrails.
• How much contrails contribute to global warming is not completely clear.
• Boeing is working with supply chain to develop airplanes that can fly 100% SAF and traditional jet fuel by 2030.