SEATAC — Ever wondered why so many flights get canceled when there’s a threat of snow? It all comes down to space at Seattle-Tacoma International Airport.
Sitting on 2,500 acres, Sea-Tac is one of the smallest U.S. airports that serves over 40 million passengers a year, said spokesperson Perry Cooper. Denver International Airport, for example, has 34,000 acres, and New York’s John F. Kennedy International Airport has double Sea-Tac’s acreage.
When snow falls, specialized vehicles must spray each aircraft with de-icing liquid before takeoff. So whenever snow is in the forecast, Celley Buchanan, an Alaska Airlines vice president, said the company “proactively” cancels flights because the airline doesn’t have enough time or space to de-ice all the planes leaving Sea-Tac.
Around 100 Alaska Airlines flights to and from Sea-Tac were canceled Tuesday, amounting to about 9% of the airline’s total scheduled flights. Around 70% of affected travelers had been rebooked as of Tuesday morning, said Tricia Bruckbauer, an Alaska Airlines spokesperson.
The airline, which amounts for roughly half of Sea-Tac’s operations, is expecting to be back on schedule Wednesday but may have additional cancellations Thursday and Friday due to another winter weather system, Bruckbauer said.
The wintry weather comes as Sea-Tac experiences another wave of busy holiday travel.
Sea-Tac’s Thanksgiving travel figures reached roughly 95% of those seen in 2019, and December holiday travel is expected to be similarly around pre-pandemic levels, Cooper said.
Capt. Ron Limes, an Alaska Airlines pilot for over 20 years, said he and his fellow pilots walk around the plane ahead of every flight, examining several crucial parts to see whether they need to be treated with de-icer.
If the plane needs de-icer but doesn’t get the preflight treatment, its lift would be affected, he said.
Planes are often treated with two types of de-icer: an orange fluid made up of glycol and a lime green anti-ice gel. The first one acts like soap at a carwash and the second acts like the wax.
The de-icing fluid is required solely to get the plane into the air. While the plane is in flight, heat systems keep the aircraft ice-free, Limes said. De-icing can take up to a half-hour, and the plane has a 12- to 25-minute window to get into the air before the fluid wears off, depending on weather conditions.
At Sea-Tac, where space is limited and the airport is hemmed in by neighboring cities, staff have had to get creative in finding places to de-ice planes, Cooper said. The airport has been challenged by the rising number of flights driven by the region’s population growth, as well as what he called an increasing frequency of winter snow events.
Planes are primarily de-iced at the gate, Cooper said. But in an effort to keep flights operating on schedule, crews also de-ice aircraft on the taxiway, as well as eight airfield pads opened for de-icing three years ago.
Alaska Airlines starts to make decisions about canceling flights around 72 hours in advance, using forecasts from the National Weather Service, the Weather Company and the University of Washington’s Department of Atmospheric Sciences, Buchanan said.
Unlike other airports that operate as connection hubs, around 70% of Sea-Tac traffic either begins or ends there, Cooper said, meaning most people learn about a canceled flight from home or a hotel.
“We know how incredibly disappointing it is to cancel flights,” Buchanan said. “However, our No. 1 commitment is to safety.”
