SAF Emissions Study Sees Promising Early Data

An emissions study looking at the effects of powering both engines of an Airbus A350 with 100 percent sustainable aviation fuel (SAF) has yielded “promising” early results, according to an announcement from Airbus on Monday. Conducted by a team including Airbus, Rolls-Royce, German research center DLR and SAF producer Neste, the ECLIF3 project has so far found that “SAF releases fewer particulates than conventional kerosene at all tested engine operating conditions.” To date, the project’s A350 test aircraft has flown three flights—followed by a DLR Falcon chase plane—with the goal of comparing in-flight emissions for both kerosene and hydro-processed esters and fatty acids (HEFA) SAF.

“Engines and fuel systems can be tested on the ground but the only way to gather the full set of emissions data necessary for this programme to be successful is to fly an aircraft in real conditions,” said Steven Le Moing, Airbus New Energy Programme manager. “In-flight testing of the A350 offers the advantage of characterising direct and indirect engine emissions, including particulates from behind an aircraft at high altitude.”

The study marks the first time emissions have been measured on a commercial passenger aircraft with both engines burning 100 percent SAF. Further in-flight emissions tests using both 100 percent SAF and a HEFA/Jet A-1 blend are underway. The team has also performed ground-based emissions testing “to quantify the benefits of SAF on local air quality.” The results of the study are expected to be published by the end of next year.