The world’s first in-flight study into commercial aircraft using 100% sustainable aviation fuel (SAF) has thrown up some surprising and intriguing results regarding contrails, according to Airbus.
Within the study, known as ECLIF3, Airbus set out to explore the impact of using Neste’s 100% SAF on both Rolls-Royce Trent XWB engines of an A350. It transpired that, as well as reducing the carbon footprint, contrails were also impacted.
Airbus discovered that, when compared to a reference Jet A-1 fuel, the number of contrail ice crystals per mass of unblended SAF consumed was reduced by 56%, which the company claims could significantly reduce the climate-warming effect of contrails.
Global climate model simulations conducted by the German Aerospace Center (DLR) were used to estimate the change in the energy balance in Earth’s atmosphere – also known as radiative forcing – by contrails.
The impact of contrails was estimated to be reduced by at least 26% with 100% SAF use, compared to contrails resulting from the Jet A-1 reference fuel used in ECLIF3.
These results show that using SAF in flight could significantly reduce the climate impact of aviation in the short term by reducing non-CO2 effects such as contrails, in addition to reducing CO2 emissions over the lifecycle of SAF.
DLR chase plane
A DLR chase plane, specifically a Dassault Falcon 20ER, was used to follow the Airbus A350 to gather live information during the study.
Markus Fischer, DLR Divisional Board Member for Aeronautics, said: “The results from the ECLIF3 flight experiments show how the use of 100 percent SAF can help us to significantly reduce the climate-warming effect of contrails, in addition to lowering the carbon footprint of flying – a clear sign of the effectiveness of SAF towards climate-compatible aviation.”
Details about the new findings were shared by Airbus, DLR, Rolls-Royce and Neste on June 6, 2024, and passed to the Copernicus journal Atmospheric Chemistry & Physics (ACP) as part of a peer-reviewed scientific process.
Mark Bentall, head of Research & Technology Programme, Airbus, said: “We already knew that sustainable aviation fuels could reduce the carbon footprint of aviation. Thanks to ECLIF studies, we now know that SAF can also reduce soot emissions and ice particulate formation that we see as contrails. This is a very encouraging result, based on science, which shows just how crucial sustainable aviation fuels are for decarbonising air transport.”
