The US Defense Advanced Research Projects Agency (DARPA) has tasked Boeing’s Aurora Flight Sciences with developing a flapless aircraft that relies solely on blown air to maneuver.
DARPA’s Control of Revolutionary Aircraft with Novel Effectors (CRANE) program aims to develop an X-Plane without moving control surfaces.
Instead, the aircraft would rely on active flow control (AFC), maneuvering by use of air drawn from its engine, expelled from several exhausts over its airframe at different speeds. This would reduce the aircraft’s weight, simplify its maintenance and reduce its radar signature as much as possible.
Aurora Flight Sciences, an aviation and aeronautics research subsidiary of Boeing, had already completed the preliminary design and conducted wind tunnel testing in the first phase of the program. Now DARPA has selected the company to proceed with the second phase, with the detailed design of a demonstrator.
“Over the past several decades, the active flow control community has made significant advancements that enable the integration of active flow control technologies into advanced aircraft,” CRANE Program Manager Richard Wlezien said in a statement. “We are confident about completing the design and flight test of a demonstration aircraft with AFC as the primary design consideration.”
For the third phase of the program, DARPA intends to fly a 3-ton (7,000-pound) X-Plane that will incorporate AFC technology for flight testing.
Active Flow Control, a sought-after technology
Though it has only been used on unmanned aircraft so far, the low-observability and increased operating range properties offered by this maneuvering method could find applications with the sixth generation of fighter jets currently being developed.
DARPA is not the only party interested in this new technology. In 2010, BAE Systems presented a similar aircraft, called the Demon, as part of its Flapless Air Vehicle Integrated Industrial Research (FLAVIIR). Another technology demonstrator – MAGMA, developed in partnership with the University of Manchester – successfully carried out a series of flight tests in 2019.
