A European project to understand the emissions performance of sustainable aviation fuel (SAF) when unblended with fossil jet fuel has started with the first clearance test flight of a Rolls-Royce Trent XWB-powered Airbus A350 aircraft. One of the two engines was fuelled with an unblended SAF mixture made from hydro processed esters and fatty acids (HEFA) produced in the EU and supplied by Neste. The test flight is the first in a series scheduled this month to analyse the safety of 100% SAF and next month, a German Aerospace Center (DLR) Falcon 20E ‘chase aircraft’ equipped with sensors will follow 50 metres behind the A350 test aircraft to measure the emissions directly from the SAF-fuelled engine exhaust. View the full article here.