Overview
- Google and American Airlines released results from a randomized trial on more than 2,400 eastbound night flights from the U.S. to Europe conducted January through May 2025.
- Dispatchers were offered contrail‑avoiding routes for half the flights, yet only 112 selected the option, yielding 62% fewer visible contrails and an estimated 69% reduction in warming for those flights.
- When including all flights that were given the option, contrail formation fell by 11.6% with an estimated 13.7% reduction in climatological warming for that group.
- The study found no statistically significant difference in fuel consumption between optimized and control flights.
- The collaboration involved Flightkeys and Contrails.org, and American Airlines says it will continue studies rather than make contrail avoidance a routine practice as partners seek broader integration and larger trials.