Airline Amelia and Thales announced the successful large-scale deployment of their contrail-avoidance solution. This initiative, launched in 2024 on Amelia flights between Paris and Valladolid (Spain) optimises flight plans by modifying aircraft altitude rather than lateral trajectory to avoid the formation of condensation trails (contrails). This reduces the climate impact of each flight while limiting additional fuel consumption. 

In 2025, Amelia deployed this solution across all eligible flights, including Airbus A319/320 and Embraer ERJ-145 aircraft. According to the climate-impact estimation models used, this avoided more than 2,000 tonnes of CO equivalent (CO2e) during 2025 and reduced the average climate impact per flight by around 70 per cent. The initiative is part of the DECOR project, supported by the France 2030 investment plan. 

Contrails represent a significant but concentrated share of aviation’s climate impact---about five per cent of flights generate up to 80 per cent of this effect.  

Far from purely theoretical approaches, Amelia chose precision by focusing on ‘big hits’---the rare flights where atmospheric conditions favour the formation of persistent contrails with strong warming potential. Selecting these ‘big hits’ helps account for the uncertainty associated with modelling the phenomenon by concentrating avoidance efforts only on cases where the environmental benefit is greatest. The results for 2025 included 2,000-2,500 net tonnes of CO2 equivalent avoided after reanalysis using state-of-the-art models, due to adjustments to flight plans; only 59 flights modified over the entire year, out of more than 6,400 flights operated in 2025, were needed to achieve this result; controlled additional fuel consumption.

The operational maturity of the solution developed by Amelia and Thales, mainly involving adjusting altitude before submitting the flight plan, facilitated its integration into Amelia’s flight preparation process across all teams.

Says Adrien Chabot, director of Sustainability, Amelia, “By targeting high-impact flights, we remove the barrier of scientific uncertainty about the magnitude of the phenomenon and focus on immediate action.”  

The results were analysed and verified by the scientific start-up Klima. Validation also included spot checks using ground-based cameras with support from SII and Reuniwatt, establishing a direct link between predicted avoidance and the actual observation of contrails on Amelia flights and nearby flights. Says Yannick Assouad, executive vice president, Avionics, Thales. “This success is part of Thales’ strategy: harnessing technology to accelerate the transition towards more sustainable and responsible aviation. By integrating contrail avoidance into flight-planning tools, we are demonstrating that measurable climate benefits are possible at scale.”  

Building on these results, Amelia will continue deploying these solutions in 2026. The objective is to encourage the systematic integration of non-CO2 impacts into the aviation sector’s decarbonisation strategies and into preparations for future European regulatory requirements.