A majority of domestic flights to Canadasa国际传媒檚 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.

Torontosa国际传媒檚 Pearson airport topped the list, with 51 per cent of flights delayed sa国际传媒� more than 700 sa国际传媒� 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 sa国际传媒� particularly at Pearson sa国际传媒� 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 Universitysa国际传媒檚 aviation management program, says carriers have used Ottawa as a sa国际传媒渟capegoatsa国际传媒� while scheduling more flights than they have staff or planes to provide, resulting in delays and cancellations.

sa国际传媒淭he airlines have lost some of their mojo,sa国际传媒� he said. sa国际传媒淭he government has reacted and has pumped up the resources, and wesa国际传媒檝e still got chaos.sa国际传媒�

Canadasa国际传媒檚 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.

sa国际传媒淭hat didnsa国际传媒檛 really move the needle in any direction,sa国际传媒� he said in an interview. sa国际传媒淥r maybe it did speed it up. But in the other direction, passengers also probably increased and so theresa国际传媒檚 a net-zero effect.sa国际传媒�

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.

sa国际传媒淲e just went for a drive to PEI instead,sa国际传媒� he said.

sa国际传媒淚 said screw it, if I donsa国际传媒檛 get a vacation, Isa国际传媒檓 building a (data) dashboard.sa国际传媒�

Philippe Rainville, CEO of Montrealsa国际传媒檚 airport authority, said in an interview that global flight disruptions are having a knock-on effect on domestic schedules.

sa国际传媒淚tsa国际传媒檚 a consequence of the delay in international flights,sa国际传媒� he said. sa国际传媒淭o delay a domestic flight is a lot easier because flying to major hubs in Europe, the slots are very tight. Domestically, wesa国际传媒檝e got a lot more leeway.sa国际传媒�

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.

sa国际传媒淚t creates a bottleneck and congestion and to some extent a bit of a nightmare,sa国际传媒� 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 sa国际传媒渄uty timesa国际传媒� sa国际传媒� the regulatory and contractual limits on hours worked sa国际传媒� prompting personnel gaps. Agents tied up boarding passengers for a delayed flight cansa国际传媒檛 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.

sa国际传媒淭heresa国际传媒檚 not enough of them. And if you get sick, then they get sick too,sa国际传媒� 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 sa国际传媒� nearing 2019 staffing levels sa国际传媒� and its schedule operating at just 80 per cent of 2019 volumes, said spokesperson Peter Fitzpatrick.

sa国际传媒擟hristopher Reynolds, The Canadian Press