Gulfstream late last week became the first business jet manufacturer to fly one of its aircraft on 100 percent sustainable aviation fuel (SAF). Friday’s milestone demonstration flight from the airframer’s Savannah headquarters using an unmodified G650 was conducted in conjunction with Rolls-Royce, which supplies the ultra-long-range twinjet’s BR725 engines.
During the approximately 2.5-hour flight, those engines consumed SAF consisting of a blend of fuels supplied by World Fuel in Paramount, California, and Virent in Wisconsin. In the case of the former, the fuel was derived from waste fats and plant oils using the hydroprocessed esters and fatty acids (HEFA) process, while the latter was synthesized from plant-based sugars using the synthesized aromatic kerosine (SAK) production pathway.
SAF is currently approved at blends of up to 50 percent with conventional jet-A due to most legacy engines' need for the aromatic compounds in jet-A that expand their seals, forming tight seals. In the past, Rolls-Royce told AIN that in the company's modern powerplants, such as the BR725, traditional nitrile seals have been supplanted with those made from synthetic materials such as fluorocarbon and fluorosilicon that are unaffected by aromatic content, allowing them to safely use neat SAF.
“At Gulfstream, leading our industry closer to decarbonization is a long-standing priority, and testing, evaluating, and promoting new developments in SAF takes us another step closer to that goal,” said company president Mark Burns. “We are grateful for our partnership with Rolls-Royce to be able to demonstrate yet another milestone in these efforts.”