GENEVA—As part of a broader campaign to prepare its engines for use with 100% sustainable aviation fuel (SAF), Rolls-Royce plans to run back-to-back tests of a Pearl 10X turbofan with Jet A and SAF to check emissions and validate predictions that the cleaner fuel will significantly reduce the production of contrails.

Speaking at an EBACE newsmaker event, Frank Moerta, senior vice president Strategy & Future Programs for Rolls-Royce says tests of the engine – which is in development for Dassault’s Falcon 10X business jet – represent “the next big milestone” for the company. “We want to really see what the benefit of SAF is with a HEFA-SPK (Hydroprocessed Esters and Fatty Acids Synthetic Paraffinic Kerosene). So we're testing the engine on a testbed with Jet A and then the next test will be on 100% HEFA with the same engine.”

Although the engine has been designed to operate from the start on SAF, the test is focused on emissions rather than performance. “Then we will have the evidence,” says Moerta. “CO2 is one thing but this test will be useful because we also claim that SAF will have much lower NVPM – non-volatile particulate matter - which produces contrails - are significantly better. So we can reduce the production of soot by about 90% with neat SAF without aromatics. And NOx emissions seem to be better as well. So we just want to prove this,” he says.

Further fuel testing planned by Rolls this year also include running both a BR710 and Pearl 15 on 100% SAF.