Sustainable Aviation Fuel: Virgin Atlantic’s Historic Flight 100

On November 28, 2023, the aviation industry witnessed a pivotal moment when Virgin Atlantic Flight 100 touched down at John F. Kennedy International Airport. This was not a standard passenger run; it was the first commercial aircraft to cross the Atlantic utilizing 100% Sustainable Aviation Fuel (SAF). While the engineering proved successful, the flight highlighted a glaring issue: the world knows how to make green fuel, but we cannot currently make enough of it.

The Engineering Behind Flight 100

The flight, operated on a Boeing 787 Dreamliner named Virgin Atlantic, flew from London Heathrow to New York. The primary goal was to prove that “drop-in” fuels are a reality. A drop-in fuel refers to a substitute that requires no modification to the aircraft, engines, or fuel delivery infrastructure.

The aircraft was powered by Rolls-Royce Trent 1000 engines. Under current international aviation standards, airlines are only permitted to blend SAF up to 50% with traditional kerosene. Virgin Atlantic obtained special permission from the UK Civil Aviation Authority (CAA) and the US Federal Aviation Administration (FAA) to run this test at 100% concentration.

The success of the flight demonstrated that modern jet engines can handle alternative fuels without compromising safety or performance. The pilots reported no difference in handling, and the engines performed exactly as they would have with standard Jet A-1 fuel.

The Specific Chemistry of the Fuel

To replicate the properties of traditional jet fuel, the consortium behind Flight 100 had to create a specific chemical cocktail. Jet fuel requires “aromatics,” which are chemical compounds that ensure engine seals swell correctly to prevent leaks.

The unique blend used for this flight consisted of:

  • 88% HEFA (Hydroprocessed Esters and Fatty Acids): Supplied by AirBP, this portion was derived primarily from waste fats, such as used cooking oil and animal fat.
  • 12% SAK (Synthetic Aromatic Kerosene): Supplied by Virent (a subsidiary of Marathon Petroleum Corporation), this component was made from plant sugars, specifically waste corn dextrose. This provided the necessary aromatics that HEFA lacks.

This precise 88⁄12 ratio ensured the fuel density and lubricity matched standard kerosene specifications perfectly.

Environmental Impact and Data

The data collected during the flight, analyzed by researchers from Imperial College London and the University of Sheffield, revealed significant environmental benefits.

The use of this specific SAF blend resulted in a lifecycle carbon emission reduction of approximately 64% compared to standard jet fuel. In total, the flight saved 95 tonnes of CO2.

However, the benefits extended beyond simple carbon accounting. The flight data showed a 40% reduction in non-CO2 particulate emissions. This is critical for the science of contrails. Persistent contrails trap heat in the atmosphere and contribute significantly to aviation’s total warming impact. By reducing particulates, SAF helps reduce the formation and persistence of these warming clouds.

The Supply Chain Lag

Despite the technical triumph of Flight 100, the “lag” mentioned in industry reports refers to a severe supply shortage. The technology works, but the infrastructure is virtually non-existent at the scale required.

Currently, SAF accounts for less than 0.1% of global jet fuel consumption. The aviation industry consumes roughly 100 billion gallons of fuel annually. To meet net-zero targets by 2050, production needs to scale from millions of gallons to billions of gallons in a very short window.

The Cost Barrier

The economics of SAF remain the primary hurdle. The fuel used for the Virgin Atlantic flight cost significantly more than conventional kerosene. In the current market, SAF generally costs three to five times more than traditional fossil-based jet fuel.

Most airlines operate on razor-thin margins. Without government subsidies or mandates, carriers cannot afford to switch to SAF without passing massive price hikes onto passengers.

Feedstock Limitations

There is also a physical limit to how much SAF can be made from waste oil (HEFA). There is simply not enough used cooking oil in the world to power the global aviation fleet.

The industry must pivot to second-generation technologies, such as:

  • Power-to-Liquid (PtL): Using green hydrogen and captured carbon to synthesize fuel.
  • Municipal Solid Waste: Converting household trash into fuel.
  • Alcohol-to-Jet: Converting ethanol into kerosene.

Virgin Atlantic CEO Shai Weiss emphasized that while the flight proved the plane is ready, the fuel industry is not. The UK government has mandated that 10% of aviation fuel must be SAF by 2030, but meeting this target requires billions in investment for new refineries.

Major Players Involved

This achievement was not a solo effort by Virgin Atlantic. It required a consortium of heavy hitters in the aerospace and energy sectors:

  • Boeing: Provided the airframe technical support.
  • Rolls-Royce: Conducted extensive ground testing on the Trent 1000 engine to ensure the 100% blend was safe.
  • AirBP and Virent: Manufactured and blended the fuels.
  • ICF and Rocky Mountain Institute: Provided sustainability verification.
  • UK Department for Transport: Provided funding to support the initiative.

The Future of SAF

Flight 100 was a proof of concept. It eliminated the technical excuse that “engines can’t handle it.” The conversation has now shifted entirely to policy and investment.

The United States has introduced the Inflation Reduction Act, which offers tax credits for SAF production. The European Union has its “RefuelEU” initiative. These policies aim to bridge the price gap between fossil kerosene and SAF.

For the traveler, this means that while 100% SAF flights are not coming to commercial schedules tomorrow, the blend ratio on your flights will likely increase over the next decade. The technology is proven; the factory construction is what comes next.

Frequently Asked Questions

Is SAF safe to fly with? Yes. Extensive testing by Rolls-Royce and Boeing for Flight 100 proved that SAF performs identically to traditional jet fuel. It meets all safety standards for density, freezing point, and energy content.

Did Flight 100 carry passengers? The flight did not carry paying commercial passengers. It carried Virgin Atlantic founder Sir Richard Branson, CEO Shai Weiss, government officials, engineers, and media representatives.

Why is used cooking oil the main source of SAF? Used cooking oil (HEFA) is currently the most mature and cheapest technology for making SAF. It is chemically very similar to oil-based fuels. However, because the supply of waste oil is limited, the industry must develop other methods to scale up production.

When will I fly on a plane using 100% SAF? Commercial flights using 100% SAF are likely years away. Current regulations limit the blend to 50%. Regulators need to see more data and consistent fuel quality before allowing 100% blends for general commercial service.