Contrail avoidance implemented by Thales and Amelia

Since June 2024, Thales' contrail avoidance solution has been deployed on all Paris-Valladolid flights operated by Amelia, using Embraer ERJ145 aircraft. These aircraft have a maximum cruising altitude of 37,000 feet, which is representative of jet airliners.

Contrails form when the warm moist exhaust fumes from an aircraft mix with cold ambient air, which produces ice crystal clouds that trap heat from the sun. An EU study from 2020 found that contrails are among the non-CO2 emissions (CO2eq) that contribute twice as much to global warming as aircraft CO2.

To mitigate against this, Thales’ Flights Footprint solution was integrated with Amelia’s Operational Control Centre (OCC) tools to provide alternative routes to their flight plans.

When a significant impact of contrails is detected, Flights Footprint suggests flight alternatives that allow for a reduction in climate impact, with a minimum average decrease of up to 40 per cent in the total climate impact of the flight. This flight optimisation relies on adjusting the aircraft's altitude, without changing their route, which helps to keep additional fuel consumption to below three per cent. 

Flights Footprint utilises the latest weather forecasts and advanced climate models provided by project partner Breakthrough Energy Contrails to optimise the flight plan. At the end of each flight, these climate models are applied to the actual flight path of the aircraft to assess the effectiveness of avoiding contrail formation areas. A Reuniwatt ground camera in the Bordeaux region helped validate the solution via direct observation of contrails.

Julien Lopez, head of Thales Green Operations, said that the project looked at Amelia flight plans before aircraft took off.

“And with our tools, we have checked whether this trajectory will generate - or not -contrails,” he said. “If we do identify that there will be a strong impact of contrails on this particular flight, then with Thales tools we propose an alternative to the trajectory of the aircraft in order to try and minimise, or even completely avoid, the generation of contrails.”

In a test flight on June 5, 2024, adjusting the flight plan to fly at 34,000 feet instead of 36,000 feet reduced contrail impact by 87 per cent and overall climate impact by 30 per cent, while increasing fuel consumption by 2.4 per cent.

“This flight had a very strong climate impact related to contrails,” said Lopez. “The contrails have been reduced very dramatically from 4.65 tons to 0.61 tons, so more than 87 per cent of reduction.”

Lopez continued: “What's interesting to look at is that fuel consumption has very slightly increased, only 2.4 per cent.

“An increase in fuel means increase in CO2 but…when you compare them – two per cent of additional CO2 versus 86 per cent of reduced contrails - the overall climate impact is very, very much improved with what we've done on that flight.”

Overall, the project is said to have prevented an average of more than four tons of CO2eq per flight, initially affected by contrails.

Amelia is extending this system to eligible flights in 2025, becoming the first airline to systematically implement a contrail avoidance approach. 

“From the beginning of the year we already started to make some avoidance trials…with flights performed by A320 aircraft,” said Adrien Chabot, director of Sustainable Development at Amelia.