Configured with two turbofan engines instead of three and with twin canted fins mounted on the aft body section, the X-48C is used to examine Blended Wing Body (BWB) noise levels. With a 21-foot wingspan, the 500-pound X-48 airplanes are 8.5 percent scale models of a heavy-lift, subsonic airplane with a 240-foot wingspan that the Boeing Phantom Works organization believes could be developed in the next 15 to 20 years for military cargo applications.