Already a member? Please login below for an enhanced experience. Not a member? Join today

An icy situationAn icy situation

Contaminated runways require skills you may already have

It may be hard to believe if you are just starting your pilot training, but when it comes to snow and ice on runways, you may—as contest ads say—already be a winner.
Icy Runway

Icy RunwayCritical to a landing on what may be a slippery surface—“contaminated” is the official term—is keeping the fuselage parallel to the runway centerline. Is that not what you practice on every landing, even if the reason given is protecting the flight school’s tires? And what about crosswinds? Isn’t one of the goals of any crosswind landing to stop sideways drift? That’s yet another skill that will keep you safe on ice, too.

Be aware that if your plan is to simply stay off the brakes, you’ll need 300 percent more icy runway than for a dry runway. In a 2010 study by the University of North Dakota, Professor Tom Zeidlik found that no matter what general aviation airplane you fly, from a Cessna 172 to a Cirrus SR22 or a twin-engine Piper Seminole, the percentage is always the same.

The study didn’t include actual landings; aircraft accelerated on dry pavement and reduced power to idle once reaching a long stretch of clear ice that was created by the local fire department. Zeidlik said airspeed control is even more important on slick runways—another skill you are already practicing. At one foot above the runway, “Be as slow as possible,” he said.

“Land for the worst, hope for the best,” Zeidlik said.

According to the Aeronautical Information Manual, “A runway is considered contaminated whenever standing water, ice, snow, slush, frost in any form, heavy rubber, or other substances are present.” In Alaska, landing on contaminated runways is a fact of life. And although you might not encounter runways caked with inches of snow anytime soon, you can still use the techniques pilots practice up north.

“The first order of business is knowing what the conditions are,” said Matt Gallagher, director of training and check airman at Warbelow’s Air in Fairbanks, Alaska. The company flies to villages in northern Alaska, and it has agents at each of its stops whom pilots can call for the latest conditions. For you, that means calling the airport to learn the condition of the runway. “If we know there are three or four inches of snow, we know the takeoff distance is going to be greater,” Gallagher said.

Those agents, Chief Pilot Greg Probst said, are not trained and pilots are not even sure on a particular day who the agent is going to be, because of changes in daily village life. Once an aircraft has landed, the pilot may discover more snow than expected and will use the aircraft’s momentum to take off again, Probst said.

It doesn’t have to be winter to cause a problem, Probst said. Snow and ice on the gravel runways found at many villages melt slowly in the spring. Surface water is blocked from sinking into the ground by the ice layer underneath and the surface becomes a slurry, capable of trapping a taxiing aircraft.

Gallagher mentioned one technique student pilots routinely practice: soft-field takeoffs. “Use proper flap setting, stick all the way back, and try to break free of the drag as soon as possible, level off in ground effect and build up some speed,” he said. Alaska pilots use ground effect, or pushing a cushion of air against the runway while staying a few feet above it, to great advantage, he said. Don’t try to climb until you’ve accelerated to the best climb speed.

Gallagher also made the case for additional ratings. “There’s a lot of us up here that have floatplane ratings or have flown on skis, and we’re able to apply those principles to operating into and out of hard-surfaced runways with wheeled airplanes.” That includes lifting one wheel during the takeoff roll to reduce friction and gain speed faster, as a pilot might do with a floatplane on glassy water—or an airplane equipped with skis in heavy snow.

“The soft-field landing is all about approaching in a nose-high attitude. If a person can get that, the odds are in their favor. They are able to bring their airplane to a stop in less distance,” Gallagher said. He added a technique usually found in short-field landings: “If you get the flaps up right away, that transfers the weight to the wheels. Getting the stick back allows the brakes to be more effective.”

You don’t want to lock up the brakes—something that could promote skidding—but you also don’t want to stay off the brakes. Warbelow’s teaches its pilots to apply and release the brakes as needed. “I’m feeling out the situation. It tells me what condition the runway is in,” Gallagher said.

Warbelow’s pilots are taught that if they are operating in snow, the airplane’s brakes are probably going to freeze prior to arrival. The answer to that problem is to forget about the greaser-smooth landing. Plop it down to try to break the brakes free as the aircraft starts its landing rollout, he said. When they join the company, Warbelow’s pilots are told in ground school that reduced friction on the runway—whether from snow, ice, or a combination—means a longer takeoff run and landing rollout.

Make your own decision prior to landing as to whether you will attempt it based on your own observation. Gallagher pointed out that what may appear to be a well-plowed runway to a snowplow operator may be inadequate for a pilot. “Know if that is a place you don’t want to be on that certain day,” Gallagher said.

“If we do make the decision to land, we are already thinking about being right on our airspeed, nose-high attitude, proper alignment, stuff like that. All those things come together to keep us from rolling off the end of the runway.”

Alton Marsh

Alton K. Marsh

Freelance journalist
Alton K. Marsh is a former senior editor of AOPA Pilot and is now a freelance journalist specializing in aviation topics.

Related Articles