The results could be significant for informing how SAF could be used by the industry in commercial operations in future. "The use of SAF is vital to ensuring the aviation industry can be sustainable, and is one of the key pillars of our decarbonisation strategy," Paul Stein, Chief Technology Officer at Rolls-Royce, says. The flightpath to 100% SAF Currently, SAF is ASTM-certified for blends of up to 50% conventional fuel, but these tests intend to show that aircraft engines can operate on 100% SAF as a 'drop-in' solution. This could lay the groundwork for moving such fuels towards certification of higher blend limits, removing barriers to entry by increasing the flexibility of introducing sustainable fuels within existing supply chains. Stein adds that testing will provide further proof that Rolls-Royce engines can operate on 100% SAF, "providing improved environmental performance that would add value to the aviation industry if made certifiable."