This Switchblade is a flying wing with a pod attached underneath to carry the engines, surveillance equipment and weapons. It doesn't have fuselage, a tail, tail fins or other extraneous parts: it's literally one giant wing. For most of its mission, the Switchblade will cruise at high altitude for as long as 15 hours, waiting for the signal to strike. For that part of the mission, the wing will be perpendicular to the direction of flight, like a traditional aircraft. This will minimize fuel burn, and maximize the time aloft, much like a glider.
When the time comes for a strike, the entire wing will pivot 60 degrees relative to the direction of flight. This will leave the right wing tip pointing forward, while the rest of the wing slants back. The resulting aerodynamic profile will be ideal for a high-speed assault -- in this case, up to Mach 2 for a distance of 2,500 miles. This type of pivoting wing is an oblique wing design. With the wing in the oblique position, supersonic shock waves disperse, rather than "piling up" in front of the craft and creating drag.
The Switchblade will have a 200-foot wingspan. The pod suspended beneath the wings will hold two advanced jet engines, cameras, flight computers and any missiles or bombs required for the mission. It won't have a cockpit, because it won't have a pilot. Flight control computers will handle all the flying because of the unstable wing configurations. This also prevents problems with pilot fatigue during extremely long missions.
For lots more information about the Switchblade project, flying wings and variable-wing geometry, check out the links below.
The Switchblade is not the first attempt to develop an oblique wing aircraft. A NASA wind tunnel project conducted in 1979 showed that a pivoting wing could increase fuel efficiency at supersonic speeds by as much as 100 percent [ref]. Aircraft designer Burt Rutan developed a AD-1 oblique wing prototype that helped prove the viability of an oblique wing system. (Rutan is most famous for designing SpaceShipOne, the first privately owned and funded craft to carry a human into space.)
The AD-1 allowed the wing to pivot gradually as speed increased, always positioning it for maximum efficiency at the plane's present speed. NASA hoped that the technology could lead to a more efficient supersonic commercial transport. However, testing revealed that an aircraft became extremely unstable as the wing moved into an oblique position. A human pilot could not cope with the constant, minute adjustments necessary to maintain flight under these conditions. At the time, flight control computers were not sophisticated enough to manage it, either.
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More Great Links
- AD-1 Oblique Wing http://www.dfrc.nasa.gov/gallery/Photo/AD-1/HTML/index.html
- DARPA Oblique Flying Wing http://www.darpa.mil/tto/programs/ofw.htm
- "F-22 Raptor Cost." GlobalSecurity.org, March 15, 2006. http://www.globalsecurity.org/military/systems/aircraft/f-22-cost.htm
- "The FB-111A 'Switchblade' History." FBI-111a.net, June 16, 2006. http://www.fb-111a.net/History.html
- Shachtman, Noah. "U.S. Miltary Plans Shape-Shifting Supersonic Bomber." Popular Science, July 2006. http://www.popsci.com/popsci/aviationspace/0f2505a52aceb010vgnvcm1000004eecbccdrcrd.html
- Cramer, M.S. "Sonic Boom, Sound Barrier, and Condensation Clouds." Fluid Mechanics, Cambridge University Press, 2004. http://www.fluidmech.net/tutorials/sonic/soundbarrier.htm
- "Switchblade." AirAttack.com, February 1, 2006. http://www.air-attack.com/page/9/Switchblade.html
- "USA: Northrop Awarded Contract to Develop a Conceptual Design." TMC.net, March 19, 2006. http://www.tmcnet.com/usubmit/2006/03/19/1470791.htm