Only a few red lines indicating cancelled flights popped up on the arrivals and departures board at Montréal–Pierre Elliott Trudeau International Airport on Saturday.

Canadian airlines also reported some delays, but overall, the disruptions were minor. Still, many passengers were bracing for the potential impact of trouble south of the border on their flight plans.

“It’s very scary actually to pass through the U.S. in this moment,” said passenger Montsarrat Perez-Gamboa, who was heading to Chile. “I tried to avoid it, but I didn’t have any other option, since we don’t have a direct flight from Montreal to Santiago. We must pass through U.S.”

More than 1,000 flights were grounded across the United States on Saturday, in addition to 1,000 more cancelled on Friday. This slowdown was ordered by the Federal Aviation Administration (FAA), which said it wanted to ease pressure on air traffic controllers working without pay during the government shutdown. Controllers have been calling in sick in record numbers.

U.S. Transportation Secretary Sean Duffy said there have been more complaints from pilots about stress among air traffic controllers, and more complaints about the lack of responsiveness from controllers.

The FAA order to reduce traffic does not target international flights, including transborder flights between Canada and the U.S., but experts and airlines expect some impact.

Air Canada sent a statement to CTV News on Saturday saying, “We continue to fly our normal schedule, but we have experienced some delays of our transborder flights, a relatively small number of which have resulted in cancellations.”

It added that a “goodwill policy” had been put in place for customers connecting to U.S. domestic flights on its American partner airline, United, to allow passengers to change or defer travel with no change fee.

WestJet confirmed it had experienced some operational delays, the majority lasting less than 30 minutes.

“To mitigate any further operational impacts, WestJet has adjusted flight paths around some airspace,” it said in a statement.

Porter Airlines said by midday Saturday that it had not seen any unusual flight delays or cancellations.

It encouraged passengers to check their flight status before leaving for the airport and said, “For those who have flexibility, complimentary moves to some U.S. destinations are available through Monday, when space permits.”

All airlines said they are monitoring the situation, and there is an increase in the number of flights that could be affected in the future.

For the moment, four per cent of flights are cancelled, but that could rise to 10 per cent by Friday. The disruptions could also add up leading into the American Thanksgiving holiday and affect Canadian travellers heading south.