A DLR research aircraft from Oberpfaffenhofen measures emissions when using sustainable kerosene - and flies close behind an Airbus.
Oberpfaffenhofen – There are spectacular sequences, filmed above the clouds of France from the Falcon 20E research aircraft of the German Aerospace Center (DLR) in Oberpfaffenhofen: The Falcon follows an Airbus A321neo flying ahead and flies very close to the passenger aircraft.
It measures emissions and analyzes how contrails form.
Aviation should one day be climate-neutral, and DLR has mapped out the research path to get there in a strategy brochure.
The research flights, which have been taking place over France since the end of February and will continue until the end of March in the airspace specially set aside for such purposes, are contributing to this.
Sustainable fuels, so-called Sustainable Aviation Fuel (SAF), significantly reduce the climate impact of aviation.
For the first time with pure SAF in both engines, the Airbus A321neo takes off, followed by the Falcon 20E, which is interested in the ice crystals in the Airbus exhaust plume.
The press release on the "Volcan" project, in which other companies are involved in addition to DLR, is entitled: "100 percent sustainable kerosene in the emissions check".
Around 15 flights are planned in total.
The Airbus A321neo is already a modern airliner with lean-burn engines that burn kerosene with very little soot.
In the cold atmosphere, soot particles act as strong condensation nuclei for water droplets, which freeze to form ice crystals at low temperatures - condensation trails are formed if there is sufficient humidity.
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The Falcon 20E research aircraft in the hangar in Oberpfaffenhofen.
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"We are particularly interested in how ice crystals form when the engines emit less soot," explains DLR project manager Prof. Christiane Voigt from the Institute of Atmospheric Physics.
But the Falcon not only flies close from behind.
"Alternatively, we surf with the Falcon in contrails a few kilometers behind the A321neo after they have fully formed," says Voigt.
In addition to kerosene, various variants of the sustainable fuel hefa are being tested in different operating modes of the engines and their emissions measured.
Hefa is made from paraffinic hydrocarbons, such as those obtained from used cooking oil.
The fabric is free of cyclic hydrocarbons and sulphur, which among other things ensures a reduction in soot particles.
This also reduces the number of ice crystals that make up contrails.
This reduces the climate impact, as DLR has already been able to demonstrate together with NASA.
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