United States aircraft company, Gulfstream Aerospace has completed a high-altitude flight test campaign examining whether 100 percent neat sustainable aviation fuel can reduce particle emissions linked to contrail formation. The campaign involved a Gulfstream G800 flying at altitudes of up to 50,000 feet while operating on neat SAF.
According to the company, it was the first 100 percent SAF flight for both the G800 and its RollsRoyce Pearl 700 engine. A specially modified Gulfstream G700 flew alongside the aircraft as an airborne emissions laboratory.
By operating in close formation, researchers were able to measure particulate emissions and atmospheric conditions at altitudes above those typically used by most commercial airliners, but common in business aviation.
The flight campaign was conducted with the FAA’s Center of Excellence, known as ASCENT, alongside NASA, the German Aerospace Center, Missouri University of Science and Technology, Aerodyne Research, Rolls-Royce, Montana Renewables and World Fuel Services.
Researchers compared conventional Jet A, low-sulfur Jet A and neat hydroprocessed esters and fatty acids, or HEFA, SAF. Unlike conventional jet fuel, the neat HEFA SAF used during the tests contained no sulfur or aromatics. Preliminary findings indicated a measurable reduction in particulate emissions associated with contrail formation when the G800 operated on the fuel.
“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 “This campaign reflects our strategy to lead with advanced technology, real-world testing and meaningful collaboration to better understand and reduce aviation’s environmental impact,” said Gulfstream president, Mark Burns.
Transformed into flying emissions laboratory, Gulfstream’s engineering and flight test teams spent months preparing for the campaign. The company modified the G700’s cabin to accommodate advanced instruments capable of measuring emissions while airborne.
Pilots also trained in simulators to carry out tightly controlled formation flights. These profiles allowed researchers to capture emissions close to the G800 and observe contrail development several miles behind the aircraft. “This collaboration enabled these first-ever high-altitude 100 percent SAF emissions observations, allowing the team to operate safely and efficiently while maintaining the precision needed for accurate data collection.
“This real-world data is essential to improving our models and understanding aviation’s broader environmental impact,” said research scientist at NASA, Rich Moore.
The findings will now be shared with aviation and atmospheric science researchers. Gulfstream said the data could help improve analytical models, guide future fuel standards and support operational strategies aimed at reducing aviation’s environmental impact.
“Partnering with Gulfstream was an excellent opportunity that will help inform and quantify our efforts to mitigate the impacts of persistent contrails. “We appreciate the collaboration with industry as the FAA continues to evaluate how SAF may help reduce persistent contrails,” an executive director of the FAA’s Office of Environment and Energy, Julie Marks said.
