January 1, 2008 Atmospheric Scientists recently improved the ability to forecast icy conditions at altitudes used by regional airliners. Using graphical displays and advanced weather prediction models, they can now quantify the safety risks by guiding aircraft away from areas where icing is likely to occur. The improved analysis differentiates between conditions where icing should be light and where it should be heavy.
Of all the dangers weather can pose to an aircraft, ice is often considered the worst. For three decades, the National Transportation Safety Board has repeatedly called icing a threat to air safety. Now there's a new technology that could save travel time, money, and lives.
Even with the most up-to-date weather information, commuter and small aircraft pilots are vulnerable to ice build-up on the wings.
“The best thing is to avoid it,” pilot Al Yecny told Ivanhoe.
This plane lost an engine due to ice build-up. Small aircraft are more prone to icing because they fly at lower altitudes and lack the mechanisms of larger jets that prevent icing. The NTSB blames over eight hundred deaths in the past three decades on ice. But atmospheric scientists at the National Center for Atmospheric Research in Boulder, Colorado have developed an experimental ice-forecasting tool.
“Experimental means you can use it, you can look at it, but you probably should not be making decisions, critical decisions, based on that information. The FAA has not approved it for that,“ NCAR Project Scientist, Marcia Politovich, told Ivanhoe.
Inside the cockpit, the system details where ice might form. Information is updated hourly and forecasted six hours out.
“It decreases the drag. It decreases the lift. Generally you just want to stay out of it because Mother Nature can surprise you in a nasty ways,” Politovich said. Ice not only causes crashes, but each year millions of lost dollars due to unnecessary cancellations and delayed flights … if only the pilot had changed to a safer route.
THE SCIENCE OF ICE: Ice is the frozen form of liquid water. The same substance will behave differently at various temperatures and pressures. Water (H2O) is the most familiar example. It can be a solid (ice), a liquid (water), or a gas (steam), but it is still made up of molecules of H2O, so its chemical composition remains unchanged.
At sea level, water freezes at 32 degrees Fahrenheit (0 degrees Celsius) and boils at 212 degrees Fahrenheit (100 degrees Celsius), but this behavior changes at different altitudes because the atmospheric pressure changes. In fact, get the pressure low enough and water will boil at room temperature. The critical temperature/pressure point at which H2O changes from one form to another is called a phase transition.