Nearly 2,000 Air Canada flights – roughly half of all flights – were delayed or cancelled over the Canada Day long weekend. The figures from aviation tracker FlightAware included Rouge and regional partner Jazz Aviation for the period from Saturday through Monday.

The 1,965 flight delays and cancellations stand in contrast to figures from some other Canadian carriers such as WestJet, Air Transat, and Flair Airlines, which registered lower flight disruption levels.

They also mark an uptick from the previous weekend, despite an unplanned shortage of air traffic controllers at Nav Canada that snarled the travel plans of thousands in that period.

Posts and photos of snaking lines and bulging terminals at airports in Toronto and Montreal plastered social media over the past few days, as passengers vented their frustration about late takeoffs and customer service.

“It is a sea of humanity and mayhem at the Montreal airport this afternoon,” passenger Andrew Holland said in a Twitter post Monday evening. “Stranded bags and delayed flights and huge lineup for taxis. Makes the experience at Pearson in Toronto last week feel like a picnic.”

Air Canada pointed out that the air travel sector is now in the throes of its summer peak, with 140,000-plus customers boarding the airline’s planes daily.

“Our top priority is to ensure everyone travels safely, even if it requires extra time,” spokesman Peter Fitzpatrick said in an email.

Bloated flight schedules and fewer spare planes play a role in travel turmoil, said John Gradek, who teaches at McGill University’s aviation management program, adding that disruption figures are trending upward.

“There are a lot of people flying, planes are full, and there’s very little operational reliability or operational backup,” Gradek said. “If an airplane craps out, for whatever reason – mechanical things do happen – you’ve got to fix the airplane before you go. So, you automatically take these monstrous delays or you cancel.”

Air Canada is running a more “tightly wound” schedule after the revenue collapse prompted by COVID-19 travel restrictions, Gradek added, with the company operating at roughly 90% of its pre-pandemic flight capacity.

The carrier echoed that message, pointing out how it may take longer to recover from a wrench in the gears of any system operating at full tilt.

“For example, when thunderstorms halt our operation, as we saw over the recent weekend in the US northeast, we may require more time than scheduled to get aircraft into position for their next flights,” Fitzpatrick said.

He added that Air Canada is fully staffed, with more employees than in the summer of 2019, despite running fewer flights.