Etihad Airways, the national carrier of the United Arab Emirates, has successfully performed the world’s most intensive sustainable flight testing programme, operating 42 flights over a five-day period to test operational efficiencies, technology and procedures that will reduce carbon emissions. Etihad points to Sustainable Aviation Fuels (SAF), which are in excess of six times more expensive than conventional aviation fuels at the moment and incredibly difficult to the point of impractical to procure, acknowledging that both SAF and Lower Carbon Aviation Fuel (LCAF) are needed for aviation’s energy transition. Etihad’s newest aircraft and sustainability beacon alongside its established Greenliner programme, the Sustainable50 A350-1000, officially became the first A350 to operate as an EcoFlight. Technology and processes tested included: Optimised Flight Paths: Coordinated with ANSPs to optimise flight paths, direct routing and optimised descent. Contrails Prevention: When water vapour is ejected from the engine exhaust into sufficiently cold air, it condenses, 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. Working with UK-based SATAVIA, Etihad avoiding flying into these areas, reducing non CO2 emissions.