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Deicing and Anti-Icing Unite
and remove ice. The system’s two parts are well he Icing Branch at NASA’s Glenn suited for airfoil leading edges where ice Research Center strives to increase contamination can degrade aerodynamic abilities.
aviation safety through the development
T
Tested extensively at the Icing Research Tunnel, of advanced ice protection and related technolo- the system uses much less energy than other gies. Efforts began in 1944 with the opening of products that provide equivalent protection, the Icing Research Tunnel, which was desig- thereby decreasing the operating cost.
nated an International Historic Mechanical The design of the deicing actuator, which is Engineering Landmark in 1987 for its leading a rolled-up printed circuit, enables the system to role in making aviation safer for everyone.
COMMERCIAL BENEFITS—SPINOFFS function on substantially less energy. Starting Taking advantage of this national asset and out as a flat oval, the actuator’s shape changes funding from Glenn’s Small Business Innovation to a circle when electrical energy is applied.
Research (SBIR) program, Cox & Company, This change causes the actuator to impact the Inc., of New York, New York, built an ice inside of the leading edge surface, which protection system that innovatively combines responds with a small but rapid flex movement thermal anti-icing and mechanical deicing to that expels the accumulated ice from the keep airfoils (wings and other lifting surfaces) surface of the aircraft’s erosion shield.
clear of ice.
Although no deicer can remove all accumu- In 1995, Cox proposed an ice protection lated ice, EMEDS has shown to remove ice to system equivalent to hot air or electro-thermal within 0.030 inches thickness. As soon as the anti-icing systems at a fraction of their costs. To ice reaches a certain thickness, it is expelled.
accomplish this, the system would need to Another advantage of the system is its resis- provide an effective means of protecting the tance to deterioration from sun exposure and leading, or front, edge of aerodynamic surfaces the harsh icing environment. While systems with limited use of power. Similar systems are with rubber leading edge surfaces require known as “low power.” Cox’s concept was to periodic replacement, EMEDS’ metal leading combine an anti-icing system with a mechanical edge surface enables it to last for the life of an deicer developed by NASA called the Electro- airplane.
Mechanical Expulsion Deicing System (EMEDS).
The anti-icing element of this hybrid would reduce the aerodynamic losses associated with deicing systems.
Using this idea, the firm developed the Cox Low Power Ice Protection System. The anti-icing element of the system heats the leading edge of the airfoil, preventing ice from forming. Past the leading edge, EMEDS functions to break up Tests conducted at the Cox & Company Icing Wind Tunnel at LaClerc Icing Research Laboratory helped solve the problem of removing ice from airfoils.
74 PUBLIC SAFETY Cox’s innovation, which The Cox Low Power Ice Protection System is combines thermal anti- the first new aircraft ice protection system that icing and mechanical has been approved by the Federal Aviation deicing, was tested Administration (FAA) for use on a business jet extensively by Cox Ice in 40 years. According to Andrew Reehorst, an Protection Systems icing research engineer at Glenn, “the FAA engineers at Glenn approval culminates 20 years of NASA efforts to Research Center’s Icing foster the development of a practical, low power Research Tunnel. ice-protection technology.” For Cox & Company, COMMERCIAL BENEFITS—SPINOFFS the FAA certification gives them credibility in the commercial marketplace.
The system is in production for Raytheon Aircraft’s Premier I six-passenger business jet, where it is used on the horizontal stabilizer.
VisionAire has also selected the system for its Vantage business jet, and other companies are considering its use. While the system is cur- rently sized for Premier class aircraft, there are no apparent constraints prohibiting its use on aircraft of any size. The company is investigating further applications, such as adapting the system for unmanned aerial vehicles and other military aircraft. EMEDS is also a viable candidate to replace pneumatic boots and other forms of ice protection. ❖ 75 PUBLIC SAFETY