Clean sweep at Northrop

has been selected by the US Department of Defense to design the first-ever supersonic flying wing aircraft that can vary the sweep of its wing for the most efficient flight performance.

The Defense Advanced Research Projects Agency (DARPA) has awarded a contract to Northrop Grumman's Integrated Systems sector for the first phase of its Oblique Flying Wing (OFW) program, which aims to design and conduct flight tests of an experimental tailless, supersonic, variable-sweep flying wing. DARPA's goal is to demonstrate that such aircraft are feasible so that similar designs can be considered for future military missions.

The oblique flying wing would vary its wing sweep (the angle of the wing's leading edge relative to the direction of flight) depending on its speed. At low speeds the wing sweep is relatively low, providing an efficient aerodynamic design. At high speeds the wing is highly swept, reducing supersonic wave drag.

The supersonic design envisioned by the OFW program offers potential benefits for missions requiring rapid deployment, long range and long endurance. In theory, an oblique flying wing could maximise its performance in every flight regime: takeoff or landing, high or low altitude, supersonic or subsonic speed.

During the program's first phase, which will conclude in November 2007, Northrop Grumman will conduct technology maturation to reduce the risk of the critical technologies associated with its OFW concepts and develop a preliminary design for the experimental aircraft. DARPA is providing funding of $10.3 million for this phase.

The preliminary design effort could be followed by a second phase to finalise the design, then build an experimental aircraft and flight test it. First flight of this "X-plane" is envisioned in 2010 or 2011.