Cathay Pacific has started testing Google's artificial intelligence-powered contrail avoidance technology across its flight network, as the airline explores whether predictive AI can help reduce the climate impact of aviation without major changes to existing aircraft or fuel.
The Hong Kong-based carrier is the first commercial airline in the Asia-Pacific region to work with Google on contrail avoidance research and the first airline globally to test the technology on ultra-long-haul flights.
An initial operational trial began in late 2025 and targeted more than 100 flights. Over 80 flights were selected to follow contrail avoidance routes. Google estimates these flights achieved roughly a 40% reduction in the warming impact associated with contrails.
One of the routes tested was the Hong Kong-Singapore corridor, where persistent contrails can frequently form. Early analysis found that relatively small altitude adjustments could help aircraft avoid conditions in which contrails develop. Actions taken on this route accounted for more than half of the total estimated climate impact reduction recorded during the trial.
Google's system combines AI-based predictive models with satellite imagery and weather intelligence to forecast areas where contrails are likely to form. Flight dispatchers and pilots can then use these forecasts to consider altitude adjustments, similar to how aircraft may change altitude to avoid turbulence.
Cathay has integrated Google's forecasts with its internally developed Electronic Flight Folder and in-flight connectivity. This gives pilots access to changing contrail forecasts alongside operational information during flights, allowing decisions to be assessed within normal cockpit procedures.
Contrails are the white trails sometimes produced behind aircraft when water vapour from engine exhaust freezes into ice crystals under particular atmospheric conditions. Some persistent contrails can trap heat in the atmosphere, contributing to aviation's non-CO2 climate impact.
While the initial findings were described as encouraging, Cathay and Google said further research is required before conclusions can be drawn about implementing contrail avoidance more broadly across airlines and airspaces.
The companies are now moving into a larger second phase of flight trials covering Cathay's Asian and transpacific network. Contrails.org, a nonprofit initiative focused on advancing contrail mitigation science, has also joined the project.
The expanded trial will provide additional real-world operational data to evaluate the benefits, limitations and practical requirements of using AI-powered contrail forecasts in commercial aviation.
For Google and Cathay, the programme represents an effort to test how predictive AI can be integrated into existing airline operations to address aviation emissions beyond carbon dioxide.
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