Future green aircraft. Illustration of three designs produced by the aviation industry in 2011 in response to a NASA challenge to design future aircraft that were more fuel efficient,less polluting,and less noisy. They are: a flying wing design (Northrop Grumman,upper left),a hybrid wing body design (Boeing,upper right),and a box wing design (Lockheed Martin,lower left). The designs include advanced composite materials,aerodynamic and laminar flow control,advanced turbofan engines,and novel noise reduction strategies. The designs were assessed by NASA Aeronautics Research Mission Directorate's Environmentally Responsible Aviation Project |