NASCAR Windshield Laminates Gaining Military Following
The coatings are made of Mylar, a polyester film first created in the 1950’s, and feature the ability to be peeled away, which leaves the windshield beneath unscratched. The inspiration for the product, military officials said, was NASCAR’s application of the coatings to hardened plastic windshields.
Pro-tint Inc. and United Protective Technologies Inc., both based in North Carolina, have teamed up to adapt their racetrack-proven windshield screens for use on military helicopters.
The private sector provided an almost ready-made solution to a new problem facing the U.S. military, with a company simply waiting to be called.
“A lot of times, the Army reacts to problems instead of being proactive,” said Nathan Bordick, an engineer working on the project at the Aviation Applied Technology Directorate in Fort Eustis, Va. “Someone just said, ‘Hey, NASCAR is doing this—why can’t we?’”
Pro-tint introduced its tear-away film to race teams in 1997, after NASCAR officials required a switch to Lexan windshields rather than stock glass to protect drivers from flying debris.
Lexan is a clear, tough plastic that is widely used in various applications, from bus stop windbreaks to security windows. However shatterproof, Lexan tends to chip, and if scratched, the sun’s glare can create a white haze that impedes a driver’s view. After several hundred miles, the damage makes the windshields nearly impossible to see through.
And so a market was born. Coatings began to appear on the racing circuits, with Steve Fricker, of Pro-tint, producing a tear-off coating to preserve the Lexan. The thin layer provides a degree of strength to the glass, but its true advantage lies in the ability to be stripped away, removing any superficial damage.
Pro-tint’s product was designed to endure speeds reaching more than 200 miles per hour without coming off. It reduces ultraviolet radiation by 99 percent without hampering visibility, and features 33,100 pounds per square inch of tensile strength.
Pro-tint partnered with United Protective to market the product to the defense industry. It was not received warmly until windshield damage from harsh desert conditions started plaguing the helicopter fleets in Iraq and Afghanistan during recent engagements.
The polycarbonate/glass, shatterproof windshields of helicopters are similar to the NASCAR’s Lexan, so the application is logical. However, the Mylar coatings required changes to reflect the performance requirements of combat helicopters.
“We had to make some serious modifications,” said Barbee. “The speeds are comparable, but the conditions are very different.”
United Protective, relishing the new market and forming acronyms accordingly, dubbed its product Advanced Screen Saving Aviation Layered Tearaways, or ASSALT. The companies first pitched the concept of applying these films to defense platforms in early 2002, but the idea did not gain any traction until late last year, said Brent Barbee, engineering vice president of United Protective.
“We’ve done a lot of testing in that time,” Barbee said, referring to a grueling regimen of more than 100 landings at the Kofa Dust Course at Yuma Proving Ground in Arizona.
The course is used sometimes to test brown out helicopter landings, where the dust, rocks and debris are so thick the pilots cannot see. The environment is hell on windshields, and a logical place to test window protection technology. “It did very well,” Bordick said simply.
Black Hawk helicopters have the greatest need for the material, but program managers from the Chinook and Apache programs also are interested, Bordick noted. The Kiowa’s geometrically unique windshields pose a problem, but using the Mylar on the rest of the helicopter fleet “should fall right into line,” according to Bordick.
While most of the details are proprietary, Barbee and Bordick said that some unique requirements involved the ability of night vision to work through the films, the application and tear-away abilities of the Mylar and resistance to a wider range of environmental pressures. The military version was designed to withstand high altitudes, having survived testing on small prop airplanes.
Bordick said the Mylar’s tendency to retain electrostatic energy, potentially shocking ground crews or passengers, was fixed by adding an additional layer of material he refused to identify because it was proprietary information. This new configuration is being tested, and its approval is the last hurdle before ASSALT is shipped to desert war zones.
Data from the tests is pending, but with managers from various helicopter programs already in agreement, it will be deployed once the directorate approves the material. The hope was to install the material early next year, Bordick said.
“All the right people are on board,” he noted. “We just have to work out the bugs.”
Replacing the windshield of a Black Hawk currently costs $3,000 to $7,000, depending on which piece is damaged, for the materials alone. Bordick said the estimated cost of purchasing and applying the Mylar on an existing windshield is several hundred times cheaper, about $100 per application.
A single layer on a helicopter windshield can last four to six months without replacement in constant harsh conditions, and a full year if the helicopter is stored out of the elements, Barbee said. United Protective boasts that windscreen life spans could potentially become infinite by applying two layers of the product, while keeping a primary coating on the Lexan at all times.
Fricker, the product’s inventor for Pro-Tint, said the first step in the creation of the film was to determine the proper thickness of material “that allowed a team to remove one layer of film without leaving residue for dirt and grime to stick to.”
Fricker and his colleagues experimented with the thickness of the layers and different adhesives. NASCAR teams evaluated the process and provided valuable feedback.
A thin layer of adhesive is applied on one side, and a scratch resistant coating on the other. This has been engineered for the racing industry so that up to 10 layers can be used without hampering visibility or durability.
NASCAR and military doctrines are similar because lives are at stake based on the performance of their products, Fricker said.
“While competing for millions of dollars and their sponsors who spend millions, their common goal is results,” he noted about NASCAR teams. “They want the best products they can use, because the cost of failure is too high.”