Google and Cathay Pacific expand their contrail trial into a larger randomized study
Google and Cathay Pacific are turning a contrail-avoidance trial covering more than 80 flights into a larger randomized controlled study. With Contrails.org joining, the second phase will test operational feasibility on ultra-long-haul routes across Asia and the Pacific. The estimated 40 percent reduction in warming impact from the first phase is an early result from Google's satellite analysis, not an independent measurement, and no extra-fuel figure has been published.
Artificial Intelligence··Evening
More than 80 flights used adjusted routes
The first Google and Cathay Pacific trial, which began in late 2025, targeted more than 100 flights across the Asia-Pacific network; more than 80 used the suggested routes. The system combined AI predictions, satellite imagery and weather data to identify areas where persistent contrails could form. Google estimates that the changes reduced the warming impact of contrails on those flights by roughly 40 percent. The Next Web and South China Morning Post report the result, but the measurement comes from Google's own satellite analysis.[1], [2], [3]
Small altitude changes were updated during flight
Pilots made small altitude changes to avoid cold, humid regions where persistent trails form. Predictions went to dispatchers and pilots before departure, while in-flight wi-fi and Cathay Pacific's Electronic Flight Folder delivered updates to the cockpit during the journey. Google and The Next Web report that the Hong Kong-Singapore corridor accounted for more than 50 percent of the estimated total reduction. The published account gives no figure for any additional fuel that the route changes may have consumed.[1], [2]
The second phase will be larger and randomized
Cathay Pacific and Google now plan to turn the trial into a larger randomized controlled study. South China Morning Post reports that Contrails.org will join the second phase, which will test operational feasibility on ultra-long-haul routes across Asia and the Pacific. Cathay Pacific is Google's first commercial airline partner in Asia-Pacific to use the technology in live operations. The new study does not yet turn the first phase's roughly 40 percent estimate into an independent result; the announced plan is the next step for measuring feasibility across broader routes.[3], [2], [1]
