MONTREAL -- Canadian air travellers will be largely unaffected by the grounding of Boeing's 737 Max 9 airplane, but they may want to double-check their itineraries all the same.

Some passengers could be booked on routes affected by the U.S. Federal Aviation Administration order, which grounded the Max 9 after part of the fuselage tore away from an Alaska Airlines plane Friday, leaving a gaping hole in the side of the cabin.

The grounding left tens of thousands of passengers facing cancellations south of the border, with 171 planes temporarily barred from takeoff.

No Canadian airlines operate the Max 9, but some of the big carriers have partnerships with Alaska Airlines and United Airlines, which both include the narrow-body jets among their fleets.

John Gradek, who teaches aviation management at McGill University, says the scale of the ripple effect will hinge on whether the problem was a one-off or the product of a systematic flaw.

The grounding marks another hit against Boeing's reputation after the 737 Max 8 airliner was grounded for 20 months in 2019 and 2020, costing the U.S. jet maker billions of dollars and raising questions about its reliability.

This report by The Canadian Press was first published Jan. 8, 2024.