Air France reports results from large-scale contrail reduction trial

Air France has released the findings of an operational research campaign aimed at reducing the non-CO₂ climate effects of commercial aviation, focusing on contrails. The airline said the work is part of its strategy to lower the environmental footprint of its operations.

Contrails are the white trails that sometimes form behind aircraft at high altitude, created when water vapour from engines condenses and freezes onto fine particles such as soot in cold, humid air. Most dissipate within minutes, but under certain atmospheric conditions they can persist for hours, spread out and form artificial clouds with a warming effect on the climate, according to the airline.

Between February and April 2026 the carrier ran a trial to identify and avoid areas with a high likelihood of persistent contrail formation. It covered about 4,300 commercial flights over the North Atlantic, airspace the airline described as suited to studying the phenomenon.

The project was carried out with Estuaire and Klima, two French startups acting as technology and operational partners in developing environmental mitigation solutions. The large-scale trials were also integrated into CICONIA, a European project bringing together scientific partners, airlines and air traffic control bodies.

The programme had two main aims: to deepen understanding of the atmospheric conditions that produce contrails with the greatest warming potential, and to assess the real operational feasibility of adjusting flight paths to avoid them.