Sustainable aviation fuel just crossed the Atlantic on its own, with no fossil jet fuel in the tank. A Gulfstream G600 flew from Savannah, Georgia to Farnborough, England in under seven hours, becoming the first aircraft to make the transatlantic journey on 100% SAF. The engines weren’t modified for the trip, hinting that existing planes could one day run on cleaner fuel without expensive retrofits. Gulfstream now plans to share the flight data with U.S. regulators to help certify full SAF use beyond today’s blended limits. For an industry where battery and hydrogen flight remain distant, this single crossing offers something rare: a glimpse of long-haul aviation that could actually clean up before 2050.