UNITED flies first with 100% ‘Sustainable Aviation Fuel’

This week, United Airlines made aviation history by flying from Chicago to Washington, D.C. using “sustainable aviation fuel,” or SAF as it is known in the aviation industry. SAF is a significantly less hazardous environmentally friendly option.

The trip took place aboard a Boeing 737 Max 8 carrying 100 people and consuming around 500 gallons of SAF. The right engine went 612 miles on 100 percent SAF, emitting 75 percent less CO2 than a trip on standard jet fuel, bringing us closer to making 100 percent green carbon neutral flying the norm.

100 percent SAF is a fuel mix consisting of about 80% HEFA (world energy) and 20% SAK (VIRENT) that is being developed as a replacement for approved fuels such as jet A-1. SAF has a fraction of the carbon impact of traditional fossil fuels, according to the US Department of Energy, and the country’s feedstock supplies are deep enough to pilot the entire aviation industry

The big picture: Aviation is one of the hard-to-decarbonize sectors of the economy, especially since airlines and plane manufacturers are already working to squeeze every ounce of efficiency out of an airframe, such as using lighter materials and more fuel-efficient engines.

At the moment, airlines are only allowed to utilize a maximum of 50% SAF on board. This means that any flight using SAF is now using a blend of SAF and regular jet fuel in the same engine.

What makes this flight historic is, United Airlines was granted permission to run one engine on 100 percent SAF and the other on conventional jet fuel to demonstrate that there are no operational differences. This also paves the way for more scalable SAF applications in the future of aviation.