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the future of flight

Alternative Fuels

Fuel flexibility in future engine designs

GE Aerospace is also supporting industry initiatives to approve and adopt 100 percent Sustainable Aviation Fuel (SAF) and is partnering on a new flight demonstration program to test zero-carbon hydrogen fuel combustion.

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Advancing Sustainable
Aviation Fuel

Sustainable Aviation Fuel (SAF) today and in the future. We are helping lead the industry to develop 100% SAF that doesn’t require blending with conventional jet fuel. Developed with economic, social and environmental considerations, SAF is made from non-petroleum based sources.

Sustainable Aviation Fuel (SAF)

SAF is jet fuel made from alternative sources and processes than those for fossil-based fuels, such as oils from plants, algae, greases, fats, waste streams, alcohols, sugars, and captured CO2. GE has been actively involved in assessing and qualifying SAF since 2007 and works closely with SAF producers, regulators, and operators to ensure that SAF can be widely adopted for use in aviation. More than 400,000 commercial flights have been operated using SAF since 2011, according to ATAG.

The widespread use of SAF has the potential to dramatically reduce fuel lifecycle carbon emissions up to 80% compared to jet fuel produced from petroleum. SAF made with new approaches such as power to liquids has the potential to eliminate carbon emissions.

Currently, SAF approved for use is a blend of petroleum-based Jet A or Jet A-1 fuel and a SAF component with a maximum blend limit of 50%. One of GE’s fuel experts chairs an international task force to develop standardized industry specifications supporting adoption of 100% SAF, which does not require blending with conventional jet fuel.

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All GE Aerospace and CFM International engines can operate on approved SAF … TODAY. CFM is a 50-50 joint company between GE and Safran Aircraft Engines. GE Aerospace’s extensive SAF testing and demonstration efforts include the following industry first:


First SAF commercial demonstration flight powered by CF6 engines


First SAF helicopter flight powered by T700 engines


First SAF commercial revenue flight powered by CFM56 engines


First SAF transatlantic flight of a large freight commercial airplane in 2011 powered by GEnx engines


First military jet flight using 100% SAF powered by F414 engines


First commercial airliner flight using 100% non-drop-in SAF powered by GE90 engines


First power-to-liquid (PtL) SAF commercial flight powered by CFM56 engines


First SAF flight for the commercial Sikorsky S-92 helicopter in 2021 powered by CT7 engines


Experimental passenger flight using 100% drop-in SAF in one of the two engines powered by CFM LEAP engines

What is drop-in SAF

Drop-in SAF means the fuel meets current petroleum-based jet fuel requirements and can be substituted for jet fuel without any modifications to engines and airframes, and is therefore compatible with the existing commercial fleet, as well as with other parts of the fuel distribution and storage infrastructure. Drop-in 100% SAF is not yet qualified by ASTM International, an organization that develops technical standards.

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Hydrogen as an aviation fuel

Hydrogen fuel presents a unique opportunity for the aviation industry to achieve zero carbon emissions flight. The absence of carbon in hydrogen results in combustion byproducts limited to water vapor and nitrogen oxides (NOx). GE believes hydrogen-fueled flight is technically feasible and is working to develop solutions to address product design and certification hurdles associated with the combustion of a cryogenic fuel. GE Aerospace is actively working in close cross-business collaboration with GE Research, GE Renewables, and GE Power to advance research and development supporting the use of liquid hydrogen (LH2).

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Hydrogen combustion demonstration

CFM International, a 50-50 joint company between GE and Safran Aircraft Engines, has also launched a demonstration program in collaboration with Airbus to ground and flight test a direct combustion engine fueled by hydrogen. CFM will modify the combustor, fuel system, and control system of a GE Passport turbofan to run on hydrogen, which doesn’t generate carbon emissions during the combustion process.

GE Aerospace engineers are rising to this challenge with a global hydrogen team already in place and growing. Efforts to design a new hydrogen combustor engine will draw from GE’s more than 8 million hours of operating experience with hydrogen combustion already today with land-based gas turbines.

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