Take a seat in a commercial aeroplane like a Boeing 737, gaze out the window, and you might be able to see the wing sticking out from the bottom of the fuselage of the aircraft, partially obstructing your view of the ground below.
But as of today, NASA said that it will collaborate with Boeing to create an experimental new aircraft demonstrator that is remarkably unlike from the conventional passenger planes. Long, slender wings on the aircraft will protrude from the top of the fuselage, not below the windows, but above them. These wings will also be supported by trusses since they will be longer and more thin than ordinary commercial aeroplane wings.
This new aircraft, to be known as the Sustainable Flight Demonstrator, is being developed for one straightforward reason: to figure out a way to make flying much more environmentally friendly and fuel efficient. Although that drastically better efficiency gain wouldn't come from new wings alone, that is the number that NASA is aiming for—up to 30 percent better efficiency.
The project is a "significant new NASA commitment to reducing carbon emissions in the air transportation system," which Pamela Melroy, NASA's deputy administrator, called "one of the most difficult industries to decarbonize," during a news conference in Washington, DC, today.
The aircraft will also feature two engines, one beneath each wing, and a tail in the back that is formed like a T in addition to those long, slender wings. It won't be a wide-body with two aisles like a 787 or an A350; rather, it will be a single-aisle aircraft like a Boeing 737 or an Airbus A320. The intention is for aircraft like these to fly regularly scheduled commercial flights between cities like New York City and Chicago.
The wing is the main attraction
Bill Nelson, the administrator of NASA, remarked during the occasion, "We're going to lower the fuel usage by as much as 30%—with improved engines, and look at this wing. The wing "needs a brace because it is so long and thin."
The trusses, or braces, may do another feat in addition to supporting the wings, which are what give an aeroplane the lift it needs to fly. "You can actually get lift on this brace, as well as [from] the wing, [like] the old concept of the old biplanes," Nelson continued.
All aspects of aircraft engineering involve tradeoffs: The long, slender wings of this experimental plane must be supported by those trusses, but there is a compelling reason why they were designed that way in the first place. We intend to show off this extra-long, thin wing, stabilised by the braces, which will significantly increase the fuel efficiency of commercial aircraft by reducing drag, the man stated.
Technically speaking, the design of the aircraft is known as a TTBW, or Transonic Truss-Braced Wing. Popular Science closely examined NASA's plans to develop such an aeroplane in May of 2020. Long, thin wings are said to create less drag because they can lessen vortices at the wing tips, according to aerospace engineers. Kevin James, a senior aerospace engineer with NASA, offered the following explanation at the time: "Out at the tip of the wing, where there's no more wing beyond what the air can see, the air is very clever, and it will simply just go around the tip," he said. But by lengthening the wings, "we can generate more lift more effectively."
A plane with these wings must have trusses because disadvantages to this layout include the possibility that a long, thin wing might flutter, like a bridge or a sign blowing in heavy winds. Of course, if aircraft of this type wind up replacing narrowbody aircraft like the 737, they would need to fit through the airport gate, and big wings may make that difficult.
Today, NASA and Boeing announced their plans to fly this cutting-edge, more fuel-efficient bird by 2028, with the possibility of similar aircraft entering service as early as the 2030s.
According to the International Energy Agency, more than 2% of carbon dioxide emissions from "energy-related" sources occurred globally in 2021. There are additional approaches to try to make aircraft greener, such as operating smaller planes entirely on electric power or utilising sustainable aviation fuel, in addition to researching novel aircraft designs like the TTBW in the form of the Sustainable Flight Demonstrator. Melroy added at the start of the event, "I'm still quite worried about the carbon impact of international aviation travel. We must treat the aviation industry seriously since it is a huge part of the global economy.