"Double Bubble" Architecture, Tail-Mounted Engines

"Double Bubble" Architecture, Tail-Mounted Engines Could Increase Aircraft Fuel Efficiency.

Popular Science (5/17, Dillow) reported, "An MIT team aims to bring aviation into the 21st century with two bold new designs for commercial airliners that could trim fuel use by up to 70 percent while increasing passenger capacity." The D series and H series designs "are part of a $2.1 million research contract from NASA to develop the next generation of subsonic airplanes," in which the goal "was to create a passenger jet that burns 70 percent less fuel, cuts emissions of nitrogen oxides by 75 percent, takes off from shorter runways, and reduces sound pollution." The MIT design relies on "a 'double bubble' architecture" with dual fuselages and tail-mounted engines. However, "there are drawbacks to both designs," such as increased engine stress and lower speeds.

        The CNET (5/17, Terdiman) "Geek Gestalt" blog reported, "The MIT-led team said that its designs for a so-called "N+3" airplane--meaning three generations beyond today's airplanes--could leverage new technologies like advanced airframe configurations and propulsion systems and could deliver the 70 percent fuel savings by around 2035." Ed Greitzer, a professor at MIT, said "meeting NASA's criteria for new, highly-efficient aircraft designs would require a 'radical change' from the current aviation paradigm. That's mainly because airplanes largely have the same design today as they've had for the last 50 years--an 'easily recognizable 'tube and wing' structure of an aircraft's wings and fuselage.'"