Air Canada said it has resolved computer-telecommunications issues that affected operations earlier today, but there will be delays and some cancellations due to the outage.
Air Canada is Canada's largest domestic and worldwide airline serving more than 200 airports on six continents.
Air Canada's check-in counters were back online Monday after a massive network outage snarled travellers who were trying to board their flights. The flight was scheduled to depart at 10 a.m.
People stuck in airport lines have been posting pictures on social media of lines backed up with hundreds of people waiting.
The airline has not immediately replied to a request for comment from CBC News.
"There's no communication. Everybody just says they don't know what's going on", she tells us.
Air Canada customers in Canada and overseas took to Twitter to complain of long lines, flight delays and other travel disruptions because of the computer problems.
"We're now experiencing an interruption at our customer Contact Centres and".
"We apologize for any inconvenience and are working towards restoring our service as quickly as possible", Air Canada wrote in a tweet.
It appears the problem didn't only affect Air Canada flights in this country. "Thank you for your patience".
A message shown on Air Canada's website on March 12, 2018.
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