English: An historic wind tunnel at NASA's Langley Research Center in Hampton, Va., is helping test the prototype of a new, more fuel-efficient, quieter aircraft design. Boeing Research & Technology, Huntington Beach, Calif., has partnered with NASA's Aeronautics Research Mission Directorate and the U.S. Air Force Research Laboratory, Wright Patterson Air Force Base, Ohio, to explore and validate the structural, aerodynamic and operational advantages of an advanced hybrid wing body concept called the blended wing body or BWB. NASA is flight testing one version of a 21-foot (6.4 m) wingspan BWB prototype, called the X-48B, at NASA's Dryden Flight Research Center, at Edwards AFB, Calif. The other one being tested in the Langley Full-Scale Tunnel is the X-48C. It has been modified to make it quieter. Those modifications include reducing the number of engines from three to two and the installation of noise-shielding vertical fins. The wind tunnel tests are assessing the aerodynamic effects of those modifications.