Safer, More Effective, More Efficient De-icer
n innovative NASA
ice removal system will be included with the first new general aviation
aircraft to be introduced in the United States in 15 years. The lightweight,
patented ice zapper device could help NASA meet its goal of greatly improving
commercial aircraft safety by keeping wings and other aircraft parts free
of dangerous ice during an aircraft's entire flight.
An electric current runs through parallel layers of flat, copper ribbon. A repelling magnetic field is created, causing a high acceleration to break the ice into tiny particles that fall from the airplane's surface. Even in warm climates, aircraft icing can be a problem at higher altitudes where temperatures are cold.
"The ice zapper uses one-thousandth the power and is one-tenth the weight of electro-thermal ice removal systems used today," said inventor Leonard Haslim of NASA's Ames Research Center, Moffett Field, California. "The system pulverizes ice into small particles and removes layers of ice as thin as frost or as thick as an inch of glaze.
" There are other, less effective methods to combat airframe icing, including thermal de-icing and pneumatic boots. "Thermal de-icers that melt ice use a lot of energy," Haslim said. "Also, melted ice can refreeze elsewhere on the aircraft, or larger loose ice shards can fly into the aircraft to cause damage.
" Pneumatic boots inflate slowly and need as much as a quarter inch of ice to accumulate before they start to work. They also dislodge bigger ice pieces that can damage aircraft engines, according to Haslim. "In one winter alone, 26 F/A-18 engines were damaged by ice chunks hitting engine fan blades," he said.
"The system uses a powerful electronic photoflash-like power supply combined with a thin copper ribbon that looks like a belt flattened on itself and embedded in a rubbery plastic," said Haslim. "The looped, flattened copper ribbons are bonded to wings, engine inlets and other airplane parts where ice can form.
" In less than a millisecond, the system sends bursts of high-current electricity through the two parallel layers of copper ribbon, resulting in magnetic fields that repel each other. The upper ribbon jumps less than twenty-thousandth of an inch, causing a high acceleration. The motion breaks the ice bond, shatters the ice into table-salt-size particles and expels them from the airplane's surface. The system can run continually during flight, pulsing once or twice a minute, to keep airplane surfaces ice free. The system's overlapping copper ribbon prevents electrical interference.
Lancair Inc. in Bend, Oregon, will test the ice removal system with its Lancair IV aircraft. The company will make the system available later in 1998 with the new Columbia 300, a four-seat, general aviation airplane.
In 1995, NASA licensed the ice zapper, officially known as the Electro-Expulsive Separation System, to Ice Management Systems, Inc., Temecula, California, for development and marketing. Ice Management recently agreed to develop the system for Lancair aircraft. Haslim won NASA's inventor of the year award in 1988 for the ice zapper system.
For more information, contact Dr. Leonard Haslim at Ames Research Center.
Call (650) 604-6575, Fax: (650) 604-6996. Or contact Bob Fair at Lancair
Inc.
Call (541) 923-2233. Please mention you read about it in Innovation.
This high-speed photography sequence demonstrates how the Electro-Expulsive
Separation System shatters and ejects ice from a wing model in a wind
tunnel test.
The ice zapper device keeps airplane surfaces ice-free without refreezing.
