Aircraft of the future may not look significantly different from today’s aircraft, but a peek “under the hood” will reveal technologies that are vastly different. Commercial aviation giants such as Boeing and Airbus — in addition to NASA and academia — are developing breakthrough airframe, propulsion, materials, and cabin designs that will help aircraft of the future fly quieter, cleaner, and more fuel-efficiently, with enhanced passenger comfort.
NASA Visualizes the Next Passenger Aircraft
An 18-month NASA research effort called the NASA Fundamental Aeronautics Program was launched in April 2010 (www.nasa.gov/topics/aeronautics/features/future_airplanes.html) to visualize the passenger airplanes of the future. Four industry teams submitted designs for airplanes that may enter service 20 to 25 years from now. Just beneath the skin of these concepts lie breakthrough technologies, including ultramodern shape memory alloys, ceramic or fiber composites, carbon nanotube or fiber-optic cabling, self-healing skin, hybrid electric engines, folding wings, double fuselages, and virtual reality windows. The teams were led by General Electric, Massachusetts Institute of Technology (MIT), Northrop Grumman, and The Boeing Company.
“Standing next to the airplane, you may not be able to tell the difference, but the improvements will be revolutionary,” said Richard Wahls, project scientist for the Fundamental Aeronautics Program’s Subsonic Fixed Wing Project at NASA’s Langley Research Center in Hampton, VA.
The GE Aviation team conceptualized a 20-passenger aircraft (Figure 1) that could reduce congestion at major metropolitan hubs by using community airports for point-to-point travel. Features include an aircraft shape that smoothes the flow of air over all surfaces, and electricity-generating fuel cells to power advanced electrical systems. The aircraft’s advanced turboprop engines sport low-noise propellers and further mitigate noise by providing thrust sufficient for short takeoffs and quick climbs.
With its 180-passenger D8 “double bubble” configuration, the MIT team strays farthest from the familiar, fusing two aircraft bodies together lengthwise and mounting three turbofan jet engines on the tail. Important components of the MIT concept are the use of composite materials for lower weight and turbofan engines with an ultra-high-bypass ratio for more efficient thrust.
The Northrop Grumman team foresees the greatest need for a smaller 120-passenger aircraft that is tailored for shorter runways in order to help expand capacity and reduce delays. The team’s Silent Efficient Low Emissions Commercial Transport (SELECT) concept features ceramic composites, nanotechnology, and shape memory alloys in the airframe, and ultra-high-bypass-ratio propulsion system construction. The aircraft would use smaller airports, with runways as short as 5,000 feet, for a wider geographic distribution of air traffic.
The Boeing Company’s Subsonic Ultra Green Aircraft Research (SUGAR) team examined five concepts. The team’s preferred concept, the SUGAR Volt (Figure 2), is a twin-engine aircraft with hybrid propulsion technology, a tube-shaped body, and a truss-braced wing mounted to the top. Compared to the typical wing used today, the SUGAR Volt wing is longer from tip to tip, shorter from leading edge to trailing edge, and has less sweep. It also may include hinges to fold the wings while parked close together at airport gates.
MIT Flies the Eco-Friendly Skies
MIT’s green airplane designs — which were submitted to NASA’s above-mentioned study of future aircraft designs — are estimated to use 70 percent less fuel than current planes while also reducing noise and emission of nitrogen oxides (NOx).