United Airlines operated the world’s first passenger flight on 100% drop-in sustainable aviation fuel (SAF) as part of an effort to combat climate change and demonstrate the viability of scheduled flights with SAF.
The demonstration flight took place between Chicago O’Hare International Airport and Reagan National Airport in Washington DC, aboard a Boeing 737 MAX 8 aircraft. The aircraft with 115 people on board flew for one hour and 24 minutes and then landed safely at its destination airport.
The Boeing 737 jet used a pair of LEAP-1B engines developed by CFM International, a 50-50 joint company between GE and Safran Aircraft Engines.
Currently, international standards following the process developed by ASTM (American Society for Testing and Materials) International permit airlines to use a maximum of 50% SAF in commercial flights. On this demonstration flight, United Airlines operated one of the plane’s two engines on 100% conventional jet fuel and the other one on 100% SAF – about 500 gallons (1,893 L) in each engine.
The SAF used by the jet was “drop-in” ready, meaning it is interchangeable with conventional Jet A and Jet A-1 fuel and requires no modifications to engines or airframes. This makes it compatible with the existing commercial fleet and the existing fuel distribution and storage infrastructure. Additionally, this flight was part of United’s Eco-Skies Alliance, which was launched in April 2021 and has collectively contributed toward the purchase of approximately 5.7 million gallons of SAF this year alone.
GE Aviation is also working with Emirates on plans to test 100% sustainable aviation fuel in 2022.
“Today’s SAF flight is not only a significant milestone for efforts to decarbonize our industry, but when combined with the surge in industry commitments to produce and purchase alternative fuels, we’re demonstrating the scalable and impactful way companies can join together and play a role in addressing the biggest challenge of our lifetimes,” said United CEO Scott Kirby, who was on the D.C. flight.