Gulfstream G650 and fuel tanker on airport ramp in front of Gulfstream hangar
Gulfstream demonstrated the use of 100 percent SAF with a flight last week using one of its G650 test aircraft. (Photo: Gulfstream)

Gulfstream Flies G650 Using Only Sustainable Aviation Fuel

The manufacturer claims to be the first to fly a business jet with 100 percent SAF.

Gulfstream recently became the first business jet manufacturer to fly one of its aircraft on 100 percent sustainable aviation fuel (SAF). The milestone demonstration flight from the airframer’s Savannah, Georgia 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 California-based World Fuel and Wisconsin-based Virent. 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 and tighten their seals. In the past, Rolls-Royce has said that in the company's modern powerplants, such as the BR725, traditional nitrile seals have been supplanted by those made from synthetic materials such as fluorocarbon and fluorosilicon that are unaffected by aromatic content, allowing them to safely use neat SAF.