Clearing the skies: Gulfstream demonstrates emissions reductions with SAF at 50,000 feet

Gulfstream Aerospace Corp. has become the first business aviation company to successfully complete a high-altitude flight test campaign demonstrating the potential for 100% neat sustainable aviation fuel (SAF) to reduce contrail-forming particle emissions at altitudes up to 50,000 feet.

The campaign marks the first 100% SAF flight for the Gulfstream G800 and Pearl 700 engine. The aircraft was paired with a specially modified Gulfstream G700, transformed into a flying emissions measurement laboratory. Operating in close formation, the aircraft enabled researchers to capture precise, real-world measurements of particulate matter and contrail-forming atmospheric characteristics at higher altitudes than flown by most commercial airliners, yet typical for business aviation.

Conducted in collaboration with the Federal Aviation Administration's (FAA) Center of Excellence (ASCENT), NASA, the German Aerospace Center (DLR), Missouri University of Science and Technology, Aerodyne Research, Rolls-Royce, Montana Renewables and World Fuel Services, the campaign was designed to isolate how fuel composition influences non-CO2 emissions, an area of increasing focus across science and industry.

To accomplish this, the team compared conventional Jet A, low-sulphur Jet A and neat hydroprocessed esters and fatty acids (HEFA) SAF, which contains no sulphur or aromatics. Preliminary results suggest a significant measurable reduction in the particulate emissions that contribute to contrail formation when operating on neat SAF.

"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," said Mark Burns, president, Gulfstream. "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."

Delivering these results required months of preparation by Gulfstream's engineering and flight test teams, including modifying the G700 cabin to integrate advanced in-flight emissions instrumentation. Pilots trained extensively in simulators to execute complex formation profiles needed to capture both near-field emissions and contrail evolution several miles in-trail.

"This collaboration enabled these first-ever high-altitude 100% SAF emissions observations, allowing the team to operate safely and efficiently while maintaining the precision needed for accurate data collection," said Rich Moore, research scientist, NASA. "This real-world data is essential to improving our models and understanding aviation's broader environmental impact."

The campaign provides valuable data that will be utilised in partnership with the broader aviation and atmospheric science communities. These insights will help refine analytical models, inform future fuel standards and support the development of operational strategies to reduce 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," said Julie Marks, executive director of the FAA's Office of Environment and Energy. "We appreciate the collaboration with industry as the FAA continues to evaluate how SAF may help reduce persistent contrails."

This work builds on Gulfstream's longstanding leadership in building a strong sustainable aviation future, including the industry's first trans-Atlantic flight using SAF in one engine in 2011 and the industry's first trans-Atlantic flight powered by 100% SAF in 2023. To date, Gulfstream aircraft have flown more than 3.5 million nautical miles on SAF blends.