Wing icing is one of the most frightening sights the pilot of a small airplane can see during flight. In medium and large airplanes and jetliners, special on-board equipment such as heated wing surfaces or inflatable rubber bladders on the leading edge of a wing can get rid of ice. But in small airplanes, the situation can be life – threatening if it’s not taken care of right away.
Ice accumulates on wings a couple of ways, either while flying in clouds—something only specially trained instrument pilots are allowed to do—or during a rainstorm in very cold weather.
Wing» aren’t the only part of the plane that can become covered with ice. Radio antennae can collect ice, which can block or distort radio signals, and even cause antennas to break off. The leading edge of propeller blades can build up ice layers, which can shake the engine violently because of unbalanced ice loads. Cockpit windshields can also collect thick layers of ice, blinding the pilot unless she acb right away.
Icing happens when the temperature is at or below freezing, with the water still in a liquid state. Contrary to common belief, water can remain liquid in temperatures as cold as several degrees below freezing, so-called “supercooled” water. As soon as something strikes a droplet of super-cooled water, it instantly freezes. Supercooled water in the form of tiny droplets in a cloud or supercooled water in the form of large raindrops, called freezing rain, can rapidly build up ice layers on the wings, tail surfaces, propellers, antennae and landing gear—virtually any structure on the airplane.
Icing creates two major problems: It adds massive amounts of weight to the plane, and it disrupts the smooth, aerodynamic flow of air over the airplane’s lift-producing surfaces.
The solution is to quickly fly toward warmer air. Depending on the weather conditions, warmer air might be back in the direction you came from. In other cases, lower altitude might be the right place to go. And in some special circumstances, there might be a layer of warmer air at a higher altitude, even though air temperature typically decreases at higher altitudes.
In spite of the complicated systems devised to get rid of it, icing has even been blamed for some commercial airline crashes. In January 1997, a Comair Airlines flight crashed and killed all 29 passengers and crew members aboard flight 3272 from Cincinnati/Northem Kentucky International Airport to Detroit Metropolitan Wayne County Airport. The airplane, a Brazilian-made Embraer propeller-driven plane, accumulated a layer of icing and began to lose control, perhaps before its pilots recognized the danger. Icing can happen on the ground, too, which is sometimes the cause of takeoff delays in cold weather as airport trucks spray de-icing fluid on the wings. The increased safety is worth the wait
De-icing equipment is not common on small planes for a few reasons. Some de-icing equipment is very expensive and would send the price of the airplane sky-high. It also adds extra equipment that must be inspected and maintained, adding still more cost to the expense of flying.
What’s more, most small sport planes aren’t really meant for bad weather flying. They are sometimes equipped with the flight instruments and navigation radios needed to fly in clouds, but icing is something that pilots of small – and medium-size airplanes try to avoid, even if they are equipped with de-icing gear.