Rolls-Royce has confirmed that its Pearl 700 engines successfully powered the first flight of a Gulfstream G800 using 100% sustainable aviation fuel (SAF), as part of a high-altitude flight test campaign measuring the effect of neat SAF on contrail-forming particle emissions at altitudes up to 50,000ft (15,240m).
The G800 was paired in close formation with a specially modified Gulfstream G700 configured as a flying emissions measurement laboratory, also powered by Pearl 700 engines. The trailing aircraft captured real-time measurements of particulate matter and contrail-forming atmospheric characteristics at altitudes typical for business aviation but higher than most commercial airline operations.
The campaign was led by Gulfstream in collaboration with the FAA, NASA, the German Aerospace Center (DLR), Missouri University of Science & Technology, Rolls-Royce, Aerodyne Research, Montana Renewables and World Fuel Services.
The team compared conventional Jet-A fuel, low-sulfur Jet-A and neat HEFA (hydro-processed esters and fatty acids) SAF, which contains no sulfur or aromatics. Preliminary results suggest a significant, measurable reduction in particulate emissions that contribute to contrail formation when operating on neat SAF.
“Sustainable aviation fuels in combination with compatible, ultra-efficient aero engines will not only play a vital role in decarbonising aviation but have also been shown to reduce certain non-CO2 emissions,” said Alan Newby, director of research and technology at Rolls-Royce. “The valuable insights we have gained from these latest tests at high altitudes are driving real progress in understanding aviation’s non-CO2 climate impacts and potential mitigation options.”
All of Rolls-Royce’s in-production Trent and business aviation engines can operate with 100% SAF, although the fuel is currently only certified for blends of up to 50% with conventional jet fuel. SAF has the potential to reduce net CO2 lifecycle emissions by approximately 80% compared to conventional fuel.
