A majority of domestic flights to Canada害羞草研究所檚 busiest airports were delayed or cancelled over the past week as the effects of an overloaded international network continue to ripple across the country.

Some 54 per cent of flights to the four largest airports were bumped off schedule in the seven days between June 22 and 28, according to analytics firm Data Wazo.

More than 44 per cent of the 4,815 flights were delayed while 8.5 per cent were scrapped altogether.

Toronto害羞草研究所檚 Pearson airport topped the list, with 51 per cent of flights delayed 害羞草研究所� more than 700 害羞草研究所� and 12 per cent cancelled. Montreal was runner-up at 43 per cent delayed and 15 per cent cancelled. The other two airports were Vancouver and Calgary.

Airlines and the federal government have been scrambling to respond to scenes of endless lines, flight disruptions, lost luggage and daily turmoil at airports 害羞草研究所� particularly at Pearson 害羞草研究所� a problem the aviation industry has blamed on a shortage of federal security and customs officers at the Canada Border Services Agency (CBSA) and the Canadian Air Transport Security Authority (CATSA).

John Gradek, head of McGill University害羞草研究所檚 aviation management program, says carriers have used Ottawa as a 害羞草研究所渟capegoat害羞草研究所� while scheduling more flights than they have staff or planes to provide, resulting in delays and cancellations.

害羞草研究所淭he airlines have lost some of their mojo,害羞草研究所� he said. 害羞草研究所淭he government has reacted and has pumped up the resources, and we害羞草研究所檝e still got chaos.害羞草研究所�

Canada害羞草研究所檚 airport security agency has hired more than 900 screeners since April, though many remain in training. Ottawa also suspended randomized COVID-19 testing of vaccinated passengers on June 11 through at least Thursday following sector demands to process international travellers more quickly.

Passengers and federally regulated transport workers are no longer required to be fully vaccinated to board a plane or train in Canada or come to work.

Ray Harris, who heads Fredericton-based data company Data Wazo, said his figures show flight disruptions have not improved in June, despite the paused tests and back-to-work staff, at the outset of peak travel season.

害羞草研究所淭hat didn害羞草研究所檛 really move the needle in any direction,害羞草研究所� he said in an interview. 害羞草研究所淥r maybe it did speed it up. But in the other direction, passengers also probably increased and so there害羞草研究所檚 a net-zero effect.害羞草研究所�

Harris is among the thousands of Canadians to feel the frustration personally. He was slated to fly with his partner and three-year-old child to Toronto from Fredericton on June 9 for a four-day getaway. Air Canada cancelled it 21 hours before departure. The rebooked flight, which had a four-hour layover in Montreal, was also cancelled.

害羞草研究所淲e just went for a drive to PEI instead,害羞草研究所� he said.

害羞草研究所淚 said screw it, if I don害羞草研究所檛 get a vacation, I害羞草研究所檓 building a (data) dashboard.害羞草研究所�

Philippe Rainville, CEO of Montreal害羞草研究所檚 airport authority, said in an interview that global flight disruptions are having a knock-on effect on domestic schedules.

害羞草研究所淚t害羞草研究所檚 a consequence of the delay in international flights,害羞草研究所� he said. 害羞草研究所淭o delay a domestic flight is a lot easier because flying to major hubs in Europe, the slots are very tight. Domestically, we害羞草研究所檝e got a lot more leeway.害羞草研究所�

Luggage is an especially sticky problem, with a shortage of baggage handlers to shuttle suitcases from late arrivals to connecting planes amid last-minute gate changes.

害羞草研究所淚t creates a bottleneck and congestion and to some extent a bit of a nightmare,害羞草研究所� Rainville said.

Kinks in one part of the air travel pipeline can snarl others, with overflowing customs areas stopping flight crews from disembarking, for example, or a lack of airline customer service agents exacerbating delays.

Flights held on the tarmac can leave crew out of 害羞草研究所渄uty time害羞草研究所� 害羞草研究所� the regulatory and contractual limits on hours worked 害羞草研究所� prompting personnel gaps. Agents tied up boarding passengers for a delayed flight can害羞草研究所檛 cover check-in counters, leading to delays in a different part of the airport. Similar snags confront baggage handlers.

Passengers say they receive last-minute emails informing them of repeated delays, aircraft changes or rebookings scheduled days after the original departure time. Reasons cited run the gamut from absent pilots to unplanned mechanical maintenance.

Long security lines also continue to plague airports amid an ongoing shortage of staff, from screeners to air traffic controllers.

害羞草研究所淭here害羞草研究所檚 not enough of them. And if you get sick, then they get sick too,害羞草研究所� said Helane Becker, an aviation analyst for financial-services firm Cowen.

Air Canada has said it continues to hire, with 32,000 employees now on its payroll 害羞草研究所� nearing 2019 staffing levels 害羞草研究所� and its schedule operating at just 80 per cent of 2019 volumes, said spokesperson Peter Fitzpatrick.

害羞草研究所擟hristopher Reynolds, The Canadian Press