Air travellers planning to fly WestJet may be concerned about potential disruptions from a strike, with dozens of flights already cancelled.

The airline scrapped 81 scheduled flights for Saturday, as a work stoppage looms for 4,400 flight attendants at Canada’s second-largest air carrier, after their union issued a 72-hour strike notice early Thursday morning. WestJet responded to the union’s move by issuing a 72-hour lockout notice.