Boeing and NASA have decided to halt the joint X-66A Sustainable Flight Demonstrator project in its current form.
Although the project will no longer lead to a demonstration flight of a modified McDonnell Douglas MD-90, it does not mean that all work related to the X-66A will be abandoned. NASA emphasizes that much of the developed material will be retained and that collaboration with Boeing will continue. However, the focus will now shift entirely to the Transonic Truss-Braced Wing (TTBW) concept. “The thin wing is the most promising design we have developed together in recent years. We are now going to focus all our attention on it,” Boeing said in a statement.
With this wing design, Boeing aims to achieve at least a thirty percent fuel saving, partly thanks to the use of new engines. Earlier tests, including wind tunnel research, showed that longer, thinner wings with diagonal braces can be much more efficient at speeds between four hundred and twelve hundred kilometers per hour. The X-66A was part of NASA’s Sustainable Flight National Partnership, but due to shifting priorities within the U.S. government, many sustainability projects are now fading from view.
Not a failure
Despite the cancellation of the X-66A demonstrator, Boeing and NASA do not view the project as a failure. Much of the knowledge and experience gained will be applied to future aircraft designs. Boeing, in any case, can put the freed-up capacity to good use. The manufacturer hopes to finally complete the certification of the 777X and the 737 MAX 7 and 10 in the near future after years of delays.