UK flight trial tests AI-guided contrail avoidance

UK flight trial will test whether tiny route changes can cut warming contrails

Operation Blue Skies will use AI forecasts and small altitude changes on North Atlantic flights to test whether persistent warming contrails can be reduced in normal airspace operations.

Passenger aircraft crossing the sky during research into contrail avoidance Image: oversnap via Getty Images / University of CambridgeOriginal source

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A UK-led aviation trial will test whether small, -guided changes to flight altitude can reduce the warming effect of persistent aircraft contrails without disrupting normal air traffic.

Operation Blue Skies is a £5 million, 30-month programme involving the University of Cambridge and other partners. Two operational trials are planned in North Atlantic airspace during the winters of 2026/27 and 2027/28.

Persistent contrails can trap outgoing heat and are to account for roughly a third of aviation's climate impact. The trial will use models to identify atmospheric conditions where a modest altitude adjustment could avoid creating them.

The important question is now practical rather than theoretical: can airlines make those changes safely, measurably and at scale within ordinary air-traffic control? The winter trials should start giving a real-world answer.