|
7
Deicing System for Airplanes

A deicer clears snow off a KC-135 Stratotanker before it takes off from Manas Air Base, Kyrgyzstan, bound for Afghanistan.

Image courtesy U.S. Air Force/Tech. Sgt. Matthew McLean

Airplane wings provide a significant amount of lift -- as long as they maintain their factory shape. Coat a wing with even a thin layer of snow or ice, however, and you disrupt its ability to keep a plane in the air. In fact, by some estimates, ice buildup can reduce lift by as much as 25 percent, which is why ground and flight crews worry so much about deicing during wintertime air travel [source: Kaydee].

The tried-and-true method to remove ice involves a three-step strategy. During the first step, deicing, airport ground crews spray a hot solution of glycol and water on an airplane's wings. This melts existing ice but does little to prevent new ice from forming. Accomplishing this requires an anti-icing step and a second type of fluid, which contains more glycol and an additional additive to make it cling to the wing surface during takeoff. Once an aircraft reaches its cruising altitude, liquids become less effective in the fight against frozen precipitation. Jet pilots solve the problem by diverting some heat from the engines to piping in the wings. Pilots of propeller-driven planes rely on rubber boots that inflate and deflate to knock ice from the wings and tail.

But what if you could build a plane with a surface so smooth that ice fails to form in the first place? Several types of nanotechnology may soon make this a reality. Scientists from GE Global Research have developed a nanotextured, superhydrophobic (or water-repellent) coating that dramatically reduces ice adhesion on wing surfaces. And a team at North Carolina State University is experimenting with a nonstick polymer that works together with an elastic substrate. The polymer gets applied to the substrate when the elastic material is stretched slightly. When the tension is relieved, the substrate pulls the polymer molecules together into a superdense configuration. Airplane wings coated with the friction-free polymers resist being coated by anything -- even ice.

|