MD-90 arrives at Boeing facility for NASA X-66A modification

A McDonnell Douglas MD-90 has been ferried to a Boeing facility where it will be modified to test the Transonic Truss-Braced Wing (TTBW) concept as part of NASA's Sustainable Flight Demonstrator project. Dubbed the X-66A, the aircraft is the space agency’s first experimental programme focused on helping the US achieve its goal of net-zero emissions. Modification work is expected to start soon, and flight testing is planned to begin in 2028. With ultra-thin wings braced by struts with larger spans