The United Airlines aircraft is the first in history to use 100 per cent sustainable fuel on a commercial flight – estimated to have emitted 75 per cent less carbon dioxide into the atmosphere than kerosene. There were 100 people on the flight, but as it was a demonstration flight, it was a pretty impressive gathering: politicians, company executives, members of the press and the airline’s CEO, Scott Kirby. The plane, a 737 MAX 8, flew from Chicago’s O’Hare International Airport to Washington’s Reagan International Airport, according to a company statement.
The sustainable aviation fuel (SAF) in question is not made from petroleum feedstocks, according to the United States Department of Energy’s government agency page, but is made from renewable biological resources and products that are generally treated as waste. The feedstocks needed to make such biofuels are available in the United States in sufficient quantities to meet the entire fuel needs of the country’s aviation segment, according to the agency.
One of the purposes of this demonstration flight was to show that SAF is no different from conventional fuel, with 1,893 litres of SAF being filled into the tank of one engine and the same amount of kerosene into the tank of the other engine. Under current regulations, airlines are only allowed to use 50% SAF on a flight. This sustainable fuel is compatible with any current fleet of aircraft.
In April 2021, the airline launched the Eco-Skies Alliance, a partnership to collectively procure 26 million litres of SAF this year alone. As SAF emits 80 percent less greenhouse gas over its entire life cycle (including the production phase), it emits 66,000 tonnes less greenhouse gas than conventional fuel and is enough to fly more than 740 million kilometres. United Airlines aims to be completely greenhouse gas free by 2050.