The ''double bubble'' D8 Series future aircraft design concept comes from the research team led by the Massachusetts Institute of Technology. Based on a modified tube and wing with a very wide fuselage to provide extra lift, its low sweep wing reduces drag and weight; the embedded engines sit aft of the wings. The D8 series aircraft would be used for domestic flights and is designed to fly at Mach 0.74 carrying 180 passengers 3,000 nautical miles in a coach cabin roomier than that of a Boeing 737-800. The D8 is among the designs presented in April 2010 to the NASA Aeronautics Research Mission Directorate for its NASA Research Announcement-funded studies into advanced aircraft that could enter service in the 2030-2035 timeframe. Image credit: NASA/MIT/Aurora Flight Sciences
