DLR research aircraft accompanies TUIfly flights to investigate climate-impacting contrails
Research support in the air: Research aircraft is currently following several regular TUIfly flights.
Partner in science: TUIfly provides flights and operational data for climate research.
Focus on climate impact: Measurements investigate how modern, particularly low-soot engines influence contrails.
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Hannover, 25. November 2025 Hanover, November 2025 – Since this week, several TUIfly passenger flights have been accompanied in the air by a research aircraft from the German Aerospace Centre (DLR). The Falcon 20E specifically follows flights at a safe distance that pass through regions with a high probability of contrail formation. This is the first time in many years that a research aircraft has directly followed a passenger aircraft. This rare deployment provides particularly valuable real-time data: the condensation trails produced by modern, low-soot ‘lean-burn’ engines are measured on board the research aircraft.
Scientists estimate that condensation trails are responsible for as much as 1 to 2% of global warming. The measurements now being carried out as part of the A4Climate project are intended to show how much new engine technologies can reduce this effect.
“As a partner to science, we are providing our flights and our operational expertise. We want to help ensure that research results are quickly incorporated into everyday aviation practice – in order to reduce the climate impact of our flights,” says Christoph Todt, Head of Environmental Sustainability at TUI Airline.
The flights are part of the newly launched EU research project A4CLIMATE, in which 17 partners from nine countries are collaborating. The project is developing practical solutions to reduce the climate impact of contrails – including new engine technologies, alternative fuels and climate-optimised flight routing. Leading partners include the DLR, the German Weather Service, the Max Planck Society, ETH Zurich, Imperial College London, Eurocontrol, Flightkeys, Breakthrough Energy and TUIfly.
Background
Since the beginning of 2025, TUIfly has routed several hundred flights specifically to avoid long-lasting contrails. In doing so, it provides researchers with real operating data for the further development of scientific models and tools.
About TUI Group
Global responsibility for sustainable economic, environmental and social action is at the heart of our corporate culture. With projects in 25 countries, the TUI Care Foundation initiated by TUI focuses on the positive effects of tourism, on education and training and on strengthening environmental and social standards. In this way, it supports the development of vacation destinations. The globally active TUI Care Foundation initiates projects that create new opportunities for the next generation.