Boeing and NASA will collaborate with U.S. airlines to advise the Sustainable Flight Demonstrator (SFD) project and development of the X-66A research aircraft.

The X-66A will test the Transonic Truss-Braced Wing (TTBW) airframe configuration and will be built from a modified MD-90 aircraft at a Boeing facility in Palmdale, Calif. It is NASA's first X-plane focused on helping achieve its goal of net-zero aviation greenhouse gas emissions.

When combined with expected advancements in propulsion systems, materials and systems architecture, a single-aisle airplane with a TTBW configuration could reduce fuel consumption and emissions up to 30% relative to today's domestic fleet of airplanes.

As part of a new sustainability coalition, Alaska Airlines, American Airlines, Delta Air Lines, Southwest Airlines and United Airlines will provide input on operational efficiencies, maintenance, handling characteristics and airport compatibility.

NASA and Boeing unveiled the new X-66A livery at the 2023 EAA AirVenture Oshkosh.