X-66A Sustainable Flight Demonstrator

The X-66A is the X-plane specifically aimed at helping the United States achieve the goal of net-zero greenhouse gas emissions by 2050. To build the X-66A, Boeing will work with NASA to modify an MD-90 aircraft, shortening the fuselage and replacing its wings and engines. The resulting demonstrator aircraft will have long, thin wings with engines mounted underneath and a set of aerodynamic trusses for support. The design, which Boeing submitted for NASA’s Sustainable Flight Demonstrator project, is known as a Transonic Truss-Braced Wing.