Emirates test flight runs plane engine entirely on sustainable aviation fuel

The flight, which took off from Dubai International Airport, was designed to demonstrate the ability to power flights entirely with SAF as part of efforts to cut carbon emissions from the aviation sector, which is notoriously difficult to decarbonise.

SAFs are typically derived by combining jet fuel with alternatives such as biofuels or recycled oils from industrial food facilities. Currently, SAF is approved for use in all aircraft, but only in blends of up to 50 per cent with conventional jet fuel. Following the successful trial on one engine, Emirates said it wanted to continue to develop the initiative with engine airframe manufacturers.

Emirates worked alongside partners GE Aerospace, Boeing, Honeywell, Neste and Virent to procure and develop a blend of SAF that closely replicates the properties of conventional jet fuel.

Eighteen tonnes of SAF were blended and at each blend ratio a host of chemical and physical fuel property measurements were carried out. After multiple lab tests and rigorous trials, they arrived at a blending ratio that mirrored the qualities of jet fuel.

While aviation releases only one-sixth the amount of carbon dioxide produced by cars and trucks, according to World Resources Institute, planes are used by far fewer people per day, meaning it is a higher per-capita source of greenhouse gas emissions.

Emirates CEO Adel Al Redha said: “This flight is a milestone moment for Emirates and a positive step for our industry as we work collectively to address one of our biggest challenges – reducing our carbon footprint.

“It has been a long journey to finally see this demonstration 100 per cent SAF flight take off. Emirates is the first passenger airline in the world to operate a Boeing 777 powering a GE engine with 100 per cent SAF. Such initiatives are critical contributors to industry knowledge on SAF and provide data to demonstrate the use of higher blends of SAF for future regulatory approvals.

“We hope that landmark demonstrations flights like this one will help open the door to scale up the SAF supply chain and make it more available and accessible across geographies, and most importantly, affordable for broader industry adoption in the future.”

Emirates has already signed up to the International Air Transport Association’s collective commitment to reach net-zero emissions by 2050. It runs a fuel-efficiency programme that investigates ways to reduce unnecessary fuel burn and emissions, wherever it is feasible.

Some of the programme’s initiatives include the operation of “flex tracks”, or flexible routings, partnering with air navigation service providers to create the most efficient flight plan for each flight.

Emirates’ first flight powered by SAF blended with jet fuel was in 2017, operating from Chicago O’Hare airport on a Boeing 777. It received its first SAF-powered A380 delivery in 2020.