A United Airlines departure from Chicago’s O’Hare air terminal to Washington Wednesday will make aeronautics history as the first commercial flight conveying travelers that is working on 100% sustainable fuel in one of two engines.

The jet engine is fueled with non-petroleum feedstocks.

The 737 Max 8, conveying in excess of 100 travelers, is scheduled to land at Reagan National Airport at 4 p.m. Wednesday.

United says it has consented to buy almost twice as much sustainable aeronautics fuel as some other airline. Sustainable flying energizes can possibly deliver a similar performance of petroleum-based jet fuel with a fraction of the carbon footprint.

The U.S. Department of Energy has estimated the country’s feedstock assets are sufficient to fulfill the projected fuel demand of the whole U.S. aviation industry.

Wednesday’s demonstration flight uses 500 gallons of sustainable aeronautics fuel for one jet engine and an equivalent amount of conventional jet fuel for the other, to show no operational difference between the two. Airlines are presently simply allowed to use a maximum of 50% sustainable aeronautics on board.

Sustainable aircraft fuels can be mixed with conventional jet fuel, however this is the first commercial flight using 100% for an engine.

United says the sustainable avionics fuel being used is viable with existing airplane fleets. The showing flight is a partnership with World Energy, the only commercial sustainable avionics fuel maker in North America.

United additionally declared a few new corporate partners for its Eco-Skies Alliance program, which was launched in April.