Rolls-Royce and Gulfstream have conducted what they say is the first original equipment manufacturer test flight of an ultralong-range business jet powered by 100 per cent Sustainable Aviation Fuel (SAF).

The test took place on the BR725-powered Gulfstream G650 twin-jet over Gulfstream’s headquarters in Savannah, Georgia.

Demonstrating that current Rolls-Royce engines for business jet and large civil applications can operate with 100 per cent SAF as a full “drop-in” option, the test lays the groundwork for moving this type of fuel towards certification.

SAF blends

At present, SAF is only certified for blends of up to 50 per cent with conventional jet fuel and can be used on all current Rolls-Royce engines.

The SAF that was used in the test consists of two components: HEFA (Hydroprocessed Esters and Fatty Acids), produced from waste fat and waste plant oils by low-carbon fuel specialist World Energy in Paramount, California, and (SAK) Synthesised Aromatic Kerosene made from waste plant-based sugars by Wisconsin-based Virent Inc.

This fuel eliminates the need for the addition of further petroleum-based components and enables a 100% drop-in SAF that can be used in existing jet engines and infrastructure without any modifications.


Dr Joerg Au, chief engineer, business aviation and engineering, director Rolls-Royce Deutschland, said: “Sustainable aviation fuels are essential for the decarbonisation of the skies, as they have the potential to significantly reduce the carbon emissions of aviation and we have already proved they can be used as a drop-in fuel to power existing engines.

“This flight test with Gulfstream is another proof point that demonstrates the compatibility of our engines with SAF, bringing us another important step closer to enabling our customers to achieve net zero carbon emissions.”

Leading the industry

“At Gulfstream, leading our industry closer to decarbonisation is a long-standing priority, and testing, evaluating and promoting new developments in SAF takes us another step closer to that goal,” said Mark Burns, president, Gulfstream.

“We are grateful for our partnership with Rolls Royce to be able to demonstrate yet another milestone in these efforts.”
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