Towards climate compatible aviation: operational feasibility of contrail avoidance by flight path adjustments

Mitigating aviation’s climate impact requires addressing both CO ₂ and non-CO ₂ effects. This study presents the operational feasibility from a real-world contrail-avoidance trial in the European airspace and demonstrates a pathway to reduce aviation’s climate footprint. A simulated 70(±8)% reduction in contrail effect was obtained through vertical and lateral pre-tactical flight trajectory adjustments of 25 commercial TUIfly flights. The trajectory changes steered the flights around the airspace volumes that the Contrail Cirrus Prediction model CoCiP predicted to produce warming contrails. Our findings indicate that the trajectory adjustments to avoid formation of warming contrails increased fuel consumption by 2.8% and extended flight time by 1.7 minutes on average for real flights. Projecting the per flight average reduction to the 2019 global fleet indicates a potential 8-32% reduction in CO ₂ -equivalent emissions achieved via pre-tactical contrail avoidance. Our findings underscore the importance of integrating contrail avoidance into routine flight operations, and can contribute to a more climate neutral future for aviation.