Air Canada says it's expecting a "normal day" after a system-wide outage affected flights across the country on Tuesday, but a spokesman for the airline urges passengers to check their flight's status before heading to the airport.

Peter Fitzpatrick says the technical issue that affected airport systems, check-in and call centres on Tuesday has been resolved and "most functions have returned to normal" as of Wednesday morning.

He says some Wednesday flights have been cancelled due to planes being out of position after cancellations Tuesday, but the company plans to operate its full schedule.

Five additional flights have also been scheduled and several others have been "upgauged," meaning they will be assigned larger than normal aircraft, to accommodate passengers who were affected by the outage.

Fitzpatrick says despite the issue, Air Canada managed to operate more than 95 per cent of its schedule on Tuesday.

At the peak of the system-wide outage, the website for Toronto Pearson International Airport showed delays of more than two dozen Air Canada flights.

1/2 We can confirm airport systems, check-in and customer call centres are beginning to come back online. We’re still expecting some flight delays and cancellations, but we are working hard to move as many customers as possible this evening and we are putting on additional... pic.twitter.com/j2dSHLselE — Air Canada (@AirCanada) May 29, 2019

We’re experiencing a computer technical issue that is affecting our airport operations, check-in and customer call centres. We’re working to resolve this issue. We thank customers for their patience — Air Canada (@AirCanada) May 29, 2019

We are currently working to support @AirCanada after they experienced a network outage earlier this evening. This affects check in and baggage. We appreciate your patience and will provide updates as they become available. — YYC (@FlyYYC) May 29, 2019

We are currently working to support @AirCanada as they resolve a temporary IT problem affecting their passenger check in. We appreciate your patience. — Toronto Pearson (@TorontoPearson) May 29, 2019