Research suggests that aircraft-generated condensation trails (contrails) cause a climate impact almost double that of direct CO2 emissions from aircraft engines alone. In order to tackle this effect airlines like Etihad, KLM and KLM Cityhopper are working with UK-based SATAVIA to avoid aircraft-generated contrails which add to surface warming. UK air navigation service provider NATS and EUROCONTROL support SATAVIA - who provide atmospheric modelling that optimises flight plans for contrail prevention - as well as airlines such as KLM, KLM Cityhopper and Etihad to test the science. In May 2022, NATS facilitated a KLM flight from Amsterdam to Edmonton, which passed through Scottish airspace, with minor modifications to the flight plan to avoid contrail-forming areas. Etihad equally avoided flying into contrail-forming areas during 22 contrail prevention flights the airline conducted over the course of three days.
Condensation trails – so-called contrails – are formed by water, soot and cool air. When water vapour is ejected from the exhaust nozzle of an aircraft engine into sufficiently cold air, it condenses and freezes around soot and other particles in the air, creating tiny ice crystals. In certain atmospheric conditions, these ice crystals create layers of cirrus clouds, causing a ‘blanket’ effect which keeps warmer air trapped in the lower atmosphere. EUROCONTROL is also closely involved in investigating the link between where aircraft fly and contrail formation and has launched ground-breaking live contrail prevention trials with DLR, the German Aerospace Center (DLR) already in 2021.