As part of NASA’s Sustainable Flight Demonstrator project, Boeing has ferried an MD-90 airplane to Palmdale, US, where it will undergo extensive modification to test the Transonic Truss-Braced Wing (TTBW) configuration.

The Sustainable Flight Demonstrator project seeks to inform a potential new generation of more sustainable single-aisle aircraft. Boeing will work with NASA to build, test, and fly the X-66A, a full-scale demonstrator aircraft.

Modification will start soon, and ground and flight testing is expected to begin in 2028.

With ultrathin wings braced by struts with larger spans and higher-aspect ratios, the TTBW design and other expected technological advances could lead to reductions in fuel use and emissions by up to 30 per cent.

Boeing and NASA have collaborated for more than a decade on the concept through the Subsonic Ultra Green Aircraft Research (SUGAR) Program.

Todd Citron, Boeing chief technology officer, said: “This marks an important step in the Sustainable Flight Demonstrator project, advances Boeing’s commitment to sustainability, and brings us closer to testing and validating the TTBW design. ”

Ed Waggoner, deputy associate administrator for programmes in the NASA Aeronautics Research Mission Directorate, said: “We at NASA are excited to be working with Boeing on the X-66A Sustainable Flight Demonstrator making critical contributions to accelerate aviation towards its 2050 net-zero greenhouse gas emission goal.”

Congressman Mike Garcia said: “Aerospace Valley has a long and distinguished history as the cradle of aerospace innovation, and this unveiling is a continuation of that critical work. Palmdale’s talented workforce and infrastructure make it the perfect location for this important project.”