Gulfstream and Rolls-Royce demonstrate contrail reduction using 100% sustainable aviation fuel
Business jet manufacturer and engine provider Rolls-Royce carried out a series of test flights using different fuels. Gulfstream and propulsion partner Rolls-Royce have hailed the initial results from tests that have shown the potential of 100% sustainable aviation fuel (SAF) to reduce contrail formation during high-altitude flights. For the campaign, Gulfstream used a G800 prototype as the lead aircraft, followed by a specially modified G700 acting as a flying emissions measurement platform. Both jets are powered by twin Pearl 700 engines. Over a series of flights, the G800 ran on standard Jet-A, low-sulphur Jet-A, and 100% HEFA-produced SAF. Data captured by the G700 allowed a comparison between the performance of the different fuel types. Operating in close formation, the aircraft enabled researchers to capture precise, real-world measurements of particulate matter and contrail-forming atmospheric characteristics at the higher altitudes – up to 50,000ft – typically flown by certain business jets, Gulfstream says. "Preliminary results suggest a significant, measurable reduction in the particulate emissions that contribute to contrail formation when operating on neat SAF," the partners state. Gulfstream says months of preparation preceded the tests, including modifying the G700's cabin to host the necessary instrumentation and simulator-based training for flightcrew to practice the complex formation profiles to be flown. "As aviation continues its work in optimising environmental efficiencies, Gulfstream is focused on advancing solutions that deliver measurable impact today while shaping a more sustainable future for flight," says Mark Burns, president, Gulfstream. "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," says Alan Newby, director of research and technology, 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." Also involved in the test programme were the Federal Aviation Administration, NASA, Germany's DLR aerospace centre, Missouri University of Science and Technology, Aerodyne Research, Montana Renewables and World Fuel Services. Although most modern jet engines are compatible with 100% SAF, current regulations limit their operation to a maximum of 50%.