Boeing X-66

The Boeing X-66 is an experimental airliner under development by Boeing. It is part of the X-plane series, and is being developed in collaboration with NASA and its Sustainable Flight Demonstrator program. It will use an extra-long and thin wing design stabilized by diagonal bracing struts, which is known as a Transonic Truss-Braced Wing. The aircraft configuration is based on research studies referred to as "Subsonic Ultra-Green Aircraft Reach (SUGAR)" which extensively studied truss-bracing and hybrid electric technologies.