Air Canada has had to cancel around 50 flights out of Toronto's Pearson Airport on Friday due to a staged sick-out by pilots.

An unusually high number of pilots called in sick, despite being fit to fly, engaging in illegal job action, said Air Canada spokesman Peter Fitzpatrick, as reported by the BBC.

The result was flight cancellations and delays concentrated in Toronto and Montreal, frustrating Air Canada passengers.

Lee-Ann Bouchard, resident of Brampton, Ontario, spoke of how difficult it would be to get to her daughter's karate tournament in Alberta now that their flight to Calgary was cancelled.

Some people are going on WestJet out of Hamilton and Kitchener. We are going to Vancouver and then back to Calgary, she told Canadian news site The Star.

We are pretty perturbed. They'll miss practice, she also added.

Steven Brown spoke to the Toronto Sun about his experience boarding one of the cancelled flights out of Pearson Airport.

One of the attendants just came on the intercom and said, 'It's cancelled, there are no other flights, you should all just go home.' There was no other explanation, Brown said.

Although he was able to re-book his flight on another airline, the Air Canada sick-out will have cost him at least 200 dollars.

I'll probably stick with WestJet until Air Canada gets (its labor situation) straightened out, he told the Toronto Sun.

The pilots' sick-out is a continuation of Air Canada's labor disputes with pilot unions.

We are, like you, incredibly frustrated by management's refusal to negotiate with us and by the collusion with the federal government forcing us into a process that we are actively contesting, wrote union chairman Captain Jean-Marc Belanger in a letter released this week, reported Reuters.

Since the wildcat strike last month, when Air Canada grounds crew walked off their job, the Canadian parliament passed a law that forced the unions and airline into arbitration.

The union has already begun challenging the arbitration law.

These recent events, including the pilots' pseudo-strike on Friday, only spell bad news for the airline.

You're going to continue to annoy customers, no doubt there will be a legal response to this, and once again the pilots will be challenged for conducting an illegal strike. The government will say they're not going to tolerate it and ratchet it up again, making it worse, rather than better, George Smith, a Queen's University labor relations expert told Reuters.