The already impressive line-up of experimental X-planes gets an addition, as US Air Force has designated the Transonic Truss-Brace Wing demonstrator from Boeing and NASA as the X-66A. The aircraft should be available for flight testing in 2028. Boeing’s truss-braced wing demonstrator gets X-66A designation.
The aircraft is also known as the Sustainable Flight Demonstrator, which is part of NASA’s Integrated Aviation Systems Program. In January, NASA announced that it will invest $425 million over the next seven years in developing and testing the TTBW aircraft. Boeing and partners will fund $725 million.
While the fuselage of the X-66A will be based on a McDonnell Douglas MD-90 fuselage, the aircraft features the advanced truss-brace wing concept with wing-mounted engines that Boeing and NASA have studied in various programs over the past decade. The long and thin wing with a high aspect ratio should offer at least a nine percent fuel burn saving, wind tunnel tests have demonstrated. Combined with new-technology engines, new materials, and advanced systems architecture, Boeing and NASA think that a combined thirty percent improvement in fuel efficiency should be possible.
No new plane this decade
This is exactly what Boeing is targeting for its next airliner, which it will not launch until the next decade. President and CEO David Calhoun caused a surprise when he announced last November that no new plane would be coming this decade, but he always said that he wants to see an aircraft with at least 25 percent better fuel efficiency. X-66A could form the foundation for the next generation of Boeing single-aisle aircraft.
“The Sustainable Flight Demonstrator builds on NASA’s world-leading efforts in aeronautics as well climate,” said NASA Administrator Bill Nelson in a media statement. “The X-66A will help shape the future of aviation, a new era where aircraft are greener, cleaner, and quieter, and create new possibilities for the flying public and American industry alike.”
“To reach our goal of net zero aviation emissions by 2050, we need transformative aircraft concepts like the ones we’re flying on the X-66A,” said Bob Pearce, associate administrator for NASA’s Aeronautics Research Mission Directorate. “With this experimental aircraft, we’re aiming high to demonstrate the kinds of energy-saving, emissions-reducing technologies the aviation industry needs.”
Validate breakthrough designs
Boeing Chief Technology Officer Todd Citron said that “the X-66A will be the next in a long line of experimental aircraft used to validate breakthrough designs that have transformed aviation. With the learnings gained from design, construction, and flight-testing, we’ll have an opportunity to shape the future of flight and contribute to the decarbonization of aerospace.”
The Air Force has used the X-designation for experimental and research aircraft since the 1940s. The X-59 Quiet SuperSonic Technology demonstrator is the most recent one and is scheduled to fly in 2024.
