WestJet pilots could go on strike ahead of the upcoming May long weekend, potentially disrupting some travellers’ flights. 

Air Line Pilots Association, Int’l (ALPA), which represents WestJet pilots, issued a 72-hour strike notice to WestJet management and the government Monday evening. 

If a deal isn’t reached by 3 a.m. ET on Friday, 1,600 flight crew members will hit the picket lines, according to the Canadian Press.

In a news release Monday, ALPA says the pilots plan to begin lawful job action which “could include grounding all aircraft and effectively shutting down operations.”

“Flight disruptions are never an ideal outcome, especially given the tremendous support our guests have shown us, and we want to continue being a major contributor to our company’s success by helping WestJet realize its growth strategy,” Chair of the WestJet ALPA Master Executive Council (MEC) Capt. Bernard Lewall said in a statement Monday. 

“However, WestJet pilots will withdraw our services to secure a contract that will fix many of the airline’s labour problems and make it a career destination for pilots once again,” he added.

The union notes that while progress has been made on most non-cost items, both sides have been unable to reach an agreement. 

The Canadian Press reports some 340 pilots have left the Calgary-based airline over the past year-and-a-half and most have joined other airlines. 

In response to the union, WestJet says its pilots are among the best paid in Canada but that a contract on par with those recently secured by some U.S. pilot groups would be financially unworkable and put the company’s future at risk, according to a statement on Monday.

The airline assures that the lockout notice does not mean a work stoppage will occur. However in the coming days, it will take necessary actions to manage the impacts. 

This includes beginning preparations to operate a reduced schedule, managing changes and cancellations, and providing flexible change and cancel options for travellers looking to make alternate arrangements. 

If flight delays or cancellations occur, WestJet says impacted travellers will be refunded or re-accommodated as applicable. 

In the event of a strike, travellers with a trip scheduled with WestJet or its subsidiary Swoop could experience some potential disruptions to their commute ahead of the upcoming Victoria Day long weekend.