The number of mid-air conflicts between drones and crewed aircraft rose in the first half of this year in most parts of Canada, with Ontario leading the way by far, according to new statistics obtained by CBC News.

Transport Canada says between Jan. 1 and June 30, there were 33 "incidents" between drones and airplanes in Ontario's skies. During the same period in 2018, there were 24, and 25 in the first six months of 2017.

Transport Canada defines an incident as a conflict between a crewed aircraft and a drone that "poses a risk to aviation safety."

"More drones are flying, so there's more probability that incidents could be reported to the department," said Ryan Coates, manager of Transport Canada's remotely piloted aircraft systems task force. "They've just increased in numbers by the thousands."

During the same time period, the number of drone-airplane conflicts has risen in other regions across Canada, with the exception of Quebec, where they've dropped since the first half of 2017, from 11 incidents to six this year.

Even so, there has only been one case of a drone striking a crewed aircraft, according to Coates.

In late 2017, a passenger plane and a drone collided over Quebec's Jean Lesage airport. There were no injuries and the plane landed safely.

In November 2016, two flight attendants were injured when a Porter Airlines flight dove suddenly on its approach to Billy Bishop Toronto City Airport.

"The crew observed a 'drone' type object on a collision course with the aircraft," the captain reported in documents obtained under a freedom of information request. "The object was described as: solid, dark, about 5-8 feet in diameter, and shaped like a doughnut."

This chart shows the number of reported drone incidents posing a risk to aviation safety, region by region. (Transport Canada)

Emails between employees at Porter Airlines and Transport Canada investigators speculate the object could have escaped from a U.S. military base near Watertown, N.Y., where "they launch and test-fly drones." Ultimately, the object was never positively identified.

Although Transport Canada attributes the spike in drone-plane conflicts in part to an increase in the number of drones in the air, the agency and drone operators agree it's difficult to estimate how quickly the number has grown in recent years, because registration has only been mandatory since June 1, when new federal regulations came into effect.

As of Aug. 2, Transport Canada says, there were 9,468 drones registered in Ontario and almost 28,000 in Canada.

The new rules stipulate everyone operating a drone that weighs more than 250 grams must register it. Operators also need to obtain a drone pilot's certificate. Only advanced-level drone pilots — who must be at least 16 years old and pass a more comprehensive exam — are allowed to fly over people, or within airspace regulated by an air traffic controller.

The number of drones registered from Jan. 9, 2019 to Aug. 2, 2019 by province. No stats were collected before January. (Transport Canada)

Drones that weigh less than 250 grams don't need to be registered, and owners don't need a licence to fly them, according to the new rules.

Local police services enforce the regulations, Coates said.

Fines for "putting aircraft and people at risk" can be up to $15,000 according to Transport Canada's website.

But Coates said Transport Canada's efforts to educate the drone-operating public began well before the new regulations came into effect.

"We've done extensive outreach ... and we think it'll have a more positive impact on safety more generally," he said. "But I think what you will see is that when you create more awareness, and you see an increase in flights, that you will see an increase in incidents that are reported."

Coates said Transport Canada will continue studying all drone/manned aircraft conflicts, to see what more, if anything, needs to be done to enhance public safety.

"We are going to monitor the kinds of incidents that come in to see if there are trends that are emerging, to see if there are steps we can take. We are committed to continually getting the message out to Canadians so that we can see safety incidents and safety reports come down."

Former airline pilot Michael Cohen, who runs a company that employs industrial drones, says as the number of users has increased, it was inevitable the number of conflicts would too. (Submitted by Michael Cohen)

Several drone operators told CBC Toronto they question Transport Canada's numbers. The number of conflicts may not be accurate because airplane pilots often misidentify the objects they come into contact with, they said.

"Transport Canada is reasonably confident that the majority of drone incidents reported actually involve drones," the agency said in an email to CBC News on Wednesday. "The department analyses drone incident data and does not include reports that lack descriptive information and/or information that would allow officials to validate the report."

Michael Cohen, a former airline pilot who now runs Toronto-based Industrial Skyworks, said the risk to crewed aircraft is biggest during takeoffs and landings, when planes are most likely to come into contact with low-flying drones.

"Any pilot's going to be worried about a vehicle that's going to conflict with their airspace, particularly on departure and arrival. That's going to be a very, very serious concern," he said.

"The potential for damage to a commercial airliner could be really, really significant, so if we have an increased amount of conflict, that's going to be problem."

Mike Campbell, a licensed drone pilot and vice-chair of the industry association Unmanned Systems Canada, questions whether the number of reported drone sightings by airplane pilots is accurate. (Kelda Yuen/CBC)

However, he said, increasingly professional commercial drone operators are mitigating the potential for problems.

"Those operators now are aviation professionals."

Drone pilot Mike Campbell, vice-chair of operations for the industry organization Unmanned Systems Canada, said as consumers become more comfortable with the new rules, the safety of airspace users will increase.

"I think it's going to take some time for the public to get fully aware of all the facts and information around flying drones," he said. "But I think at the end of the day, it'll be safer, people will be aware and the industry as a whole will be better off."