Passengers are facing disruptions to their travel ahead of a possible strike by Air Canada flight attendants, which could happen Saturday.

Air Canada said it is gradually cancelling flights starting Thursday, with a full shutdown looming by the weekend. The union representing more than 10,000 Air Canada flight attendants issued a 72-hour strike notice Wednesday and the airline responded with a lockout notice.

“We regret the impact a disruption will have on our customers, our stakeholders and the communities we serve,” Air Canada CEO Michael Rousseau said in a statement.

As talks between the two parties reached an impasse, here’s what passengers need to know.

What happened with the talks?

Air Canada said it and the union are far from reaching a deal. Some of the main sticking points include unpaid work for flight attendants when the plane is not in motion, including during boarding, deplaning and a medical emergency on the ground.

The Air Canada Component of the Canadian Union of Public Employees (CUPE) said its 10-year contract for flight attendants expired March 31.

Union President Wesley Lesosky said the airline’s proposal of an eight per cent increase in the first year wouldn’t pull members out of the poverty level, and flight attendants are still unpaid for certain work.

Flight attendants have taken a nine per cent cut to their real wages due to inflation since 2015, making Air Canada’s wage offer “below inflation, below market value, below minimum wage,” Lesosky added in a message posted online Tuesday.

Air Canada didn’t immediately respond to CTVNews.ca’s request for comment Wednesday.

However, it shared a press release on its website Wednesday, stating that its “revised comprehensive proposal” on Aug. 11 sought no concessions and offered a 38 per cent total pay hike over four years. In addition, it said the proposal addressed contract improvements such as ground pay, better pensions and benefits.

Air Canada said it tried to prevent travel disruptions by suggesting the union enter third-party, binding arbitration to settle the dispute.

But the union said it won’t enter a binding arbitration process with the airline because it wants members to vote on an agreement.

What flights are affected?

Air Canada and Air Canada Rouge flights are affected by the cancellations. Jazz and PAL Airlines, which run Air Canada Express flights, will be running normally.

Air Canada advises those without confirmed flights not to go to the airport.

What happens if flights are cancelled?

Air Canada will notify customers if their flights are cancelled and they will be eligible for a full refund. It said it made arrangements for alternative flights with other Canadian and foreign airlines.

When will the strike possibly happen?

Flight attendants could walk off the job as soon as Saturday at 12:58 a.m. ET.

What are airline passenger rights?

Gabor Lukacs, president of the non-profit advocacy group Air Passenger Rights, encourages travellers to not make changes to their plans and wait until the airline cancels their flight. He said Canada’s Air Passenger Protection Regulations (APPR) apply once the airline cancels the flight.

He said the airline will not reimburse you for any expenses you incur when you pre-emptively adjust your flight plans or travel plans.

Lukacs said the airline is responsible for meals, accommodation and a lump sum compensation of up to $1,000 per passenger, based on the length of the delay, if the cancellations are within the airline’s control.

But he also said the airline doesn’t owe passengers any lump sum compensation under the APPR once the strike occurs, although passengers travelling internationally may seek reimbursement for their expenses under the Montreal Convention.

Similar rules apply if a flight is delayed by at least three hours, he added.

Passengers have rights during a labour disruption or strike, which is considered outside of a carrier’s control under Canada’s Air Passenger Protection Regulations.

If a strike by airline staff, for instance, causes flight delays of at least three hours and cancellations, the airline must offer alternate travel arrangements or a refund. In cases where flights are cancelled due to a strike, the airline must rebook the affected passenger on another flight for free, including on a higher class if lower class seats are unavailable, Lukacs said.

The airline must also buy the affected passenger a ticket on a competitor airline if it can’t rebook the individual on one of its flights, or a partner airline leaving within 48 hours of the original departure time, he added.