HOW TO RUIN A NICE DAY AT THE AIRPORT

“It can be a beautiful day, and then you can see a wall of snow coming. When you’re in it, you’re in it, sometimes for 10 to 12 hours,” says air traffic controller André Widmer, who loves working during snowstorms. “It’s a unique beast.” Here’s what can cause trouble for Pearson’s controllers.

Winds:

Winds at ground level can change direction — which can mean shifting pilots onto other runways because planes must take off or land into the wind. There are also issues around winds at altitude, which can create turbulence.

Snow:

Seasoned travellers know a major snowstorm can muck up travel plans. When a huge snowfall is forecast, things are actually quiet because airlines tend to cancel flights to avoid issues. The most challenging time is when there are just two to three centimetres of snow, because flights still take off, but slippery runways need to be cleared and extra time is needed for de-icing planes.

Thunderstorms:

When a line of thunderstorms descends on the region, it often brings lightning. That means air traffic controllers have to route planes around the potential strikes, which can wreak havoc as planes look for detours around moving lightning.

Extreme cold:

When a deep freeze hit Pearson airport in early January 2014, the Greater Toronto Airports Authority (GTAA) faced a problem of planes stuck at gates, but unable to depart, and more planes slated to arrive. That’s when the GTAA asked Nav Canada’s air traffic controllers to implement a ground stop, essentially preventing all North American flights from arriving for 11 hours.