Quotes from the CBC article "Dozens of airline passengers in Canada hit with fines, warning letters for refusing to wear a mask" that mention AC:
"Air Canada spokesperson Peter Fitzpatrick said the airline has complied with reporting obligations and worked with Transport Canada during its investigations.
Air Canada was one of the first airlines to require face coverings and recently strengthened its policy to improve the safety of passengers and crew members, he said.
"For customers eligible for a face-covering exemption, as of Dec. 15, 2020, they will also need to present a negative COVID-19 test taken within 72 hours from departure, at the airport check-in and/or prior to boarding the flight," he wrote in an email.
"They may need another negative COVID-19 test for their return journey if the departure of their return trip exceeds 72 hours from the time the initial test was taken."
Full article:
https://www.cbc.ca/news/politics/air...ovid-1.5850825