NASA Clean-Air Program Wraps Up With X-48C Test Flight
April 13, 2013

NASA’s X-48C Advances Cleaner, Quieter Airliner Design

redOrbit Staff & Wire Reports — Your Universe Online

Tuesday´s flight of NASA´s remotely-piloted X-48C aircraft successfully concluded an eight month research campaign designed to demonstrate technological concepts for cleaner, quieter commercial air travel, the US space agency announced on Saturday.

The first flight of the Boeing-designed X-48 hybrid-wing-body subscale aircraft´s C model took place at Edwards Air Force Base in California on August 7. The April 9 flight was the 30th and final one for the manta ray-shaped scale-model vehicle, ending what NASA officials have dubbed a “productive” research project.

“We have accomplished our goals of establishing a ground-to-flight database, and proving the low speed controllability of the concept throughout the flight envelope,” Fay Collier, manager of the NASA Environmentally Responsible Aviation (ERA) Project, said in a statement. “Very quiet and efficient, the hybrid wing body has shown promise for meeting all of NASA's environmental goals for future aircraft designs.”

The X-48C, which was built by a UK company known as Cranfield Aerospace Limited, is a modified version of the X-48B blended-wing-body aircraft that was redesigned to evaluate both the low-speed stability and control of a low-noise hybrid-wing-body design.

The new design includes a flattened, tailless fuselage that has the engine mounted atop the rear part of the aircraft´s main body — a layout inspired by concept studies NASA claims are currently being tested by the ERA Project and could actually be airborne within two decade´s time.

In most ways, the X-48C retains the dimensions of its predecessor, officials from the space agency said. The vehicle´s wingspan is slightly over 20 feet and it weighs approximately 500 pounds, but unlike the B-model, the C has been altered to have an airframe noise-shielding configuration.

In addition, the wingtip winglets were relocated from the B to the C. They were moved inboard next to the engine, essentially turning them into twin tails. Furthermore, the aircraft´s rear deck was lengthened by about two feet and the B´s three 50-pound thrust jet engines were replaced with a pair of 89-pound thrust engines — giving the C an estimated top speed of 140 mph and a maximum altitude of 10,000 feet.

“Our team has done what we do best: flight-test a unique aircraft and repeatedly collect data that will be used to design future 'green' airliners,” Heather Maliska, the X-48C project manager at the Dryden Flight Research Center in California, explained. “It is bittersweet to see the program come to an end, but we are proud of the safe and extremely successful joint Boeing and NASA flight test program that we have conducted.”

“Working closely with NASA, we have been privileged throughout X-48 flight-testing to explore and validate what we believe is a significant breakthrough in the science of flight, and this has been a tremendous success for Boeing,” added Bob Liebeck, a senior technical fellow at Boeing and the aerospace firm´s Blended Wing Body (BWB) Program manager. “We have shown a BWB aircraft, which offers the tremendous promise of significantly greater fuel efficiency and reduced noise, can be controlled as effectively as a conventional tube-and-wing aircraft during takeoffs, landings and other low-speed segments of the flight regime.”