UCO TO SAF....Sustainable Aviation Fuel...? The sustainable aviation fuel is the same hydrogen fueling the TESLA or the TOYOTA CROWN; or the MUSTANG MACH E. A jet engine is an electric turbine. No one is calling you to rebuild the jet propulsion system and see for yourself but you need to understand a jet engine was always powered by electricity. The fuel on the jet whether you like it or not was used to power a generator; and Grand Dad knows this.