According to aviation data firm Cirium, nearly 28% of Air Canada’s flights, more than 8,700, landed in late October, ranking the company ninth out of 10 airlines on the continent.

The report shows that WestJet ranks last with nearly 29% delay in landings, more than 15 minutes after scheduled arrival.

Both airlines’ on-time rates, at just over 70%, are well below the North American average of 80% – itself the lowest of any region in the world – while Delta Airlines, United Airlines, Alaska Airlines and American Airlines all ranked above 85%.

Still, Air Canada’s result represents an improvement over last month’s 68% result.

In the past, Air Canada has cited a lack of air traffic controllers, bad weather and a busy route network during high demand, which can lead to longer recovery times from a disruption, as reasons for delays.

Air Canada and WestJet did not immediately respond to requests for comment.

President and CEO Michael Rousseau recently acknowledged Air Canada’s relatively low ranking, particularly after a series of flight delays in June and July.

Despite more staff and upgraded technology, the airline’s operations have not reached “expected levels,” he told analysts on a conference call in August.

The CEO cited “severe weather” – particularly thunderstorms – and “global supply chain issues” as culprits.

“We spend a lot of time improving our punctuality,” he said. Mr Rousseau described April and May as “very bad” and the following two months as worse, when about half of all flights were delayed.

He also acknowledged that a high load factor – when all planes are nearly full – leads to increased “overflow traffic” after a flight is canceled, as passengers rush to rebook with competitors and may arrive hours or even days later than expected.

“If a plane crashes, for whatever reason – mechanical problems can occur – there is no backup,” said John Gradek, who teaches aviation management at McGill University and worked at Air Canada for 18 years.

“They prefer the planes to fly rather than have them lying around just in case,” he said. The problem is that if you do it “just in case,” you’re in trouble.”

The shortage of workers must also be pointed out

The sector’s limited capacity also extends to workers transitioning from pilots to baggage handlers. In July, the International Air Transport Association called out North American air traffic control authorities, including Nav Canada, over staffing shortages that “continue to cause unacceptable delays and disruptions.”

Nav Canada has acknowledged that some delays at the country’s largest airports are partly due to a shortage of air traffic controllers.

As aircraft wait to land, the time flight crews spend circling the runway can cause flight crews’ shifts to increase by several hours each week, bringing them closer to their 28-day cap and leaving them less room for maneuver to fill the gaps in the calendar by the end of the month.

At the same time, late arrivals mean that the window for preventive maintenance between night flights becomes shorter, which in the long term can lead to mechanical problems and further delays.