Aviation experts are sounding a warning about drones, and the hazards they create when flown near airports. 

The small, remote-controlled helicopters have become both affordable and popular with hobbyists. But when flown too close to major airports, experts warn drones are dangerous. 

"The worst case is they could get ingested, be sucked into one of our engines, and that could be catastrophic," Craig Blandford of the Air Canada Pilots Association, told CBC News. 

Just last month a drone was spotted in the sky over Pearson International Airport, forcing pilots, just a few kilometres away, to change their paths and land on different runways. 

Drones have also recently alarmed pilots over Vancouver and Halifax — the drone in the latter incident was flying higher than 19,000 feet, above an Air Canada Jazz plane bound for St. John's.

So far this year pilots have reported 14 incidents of drones appearing in their path, compared to just three in 2013.

Many who use drones aren’t learning how to fly them safely, according to filmmaker and drone instructor Christiaan Cloete. 

“There's a whole lot of regulations for using [a drone] commercially, unfortunately they haven't given out regulations for [hobbyists] who are using it just for fun,” Cloete told CBC News. “So that's a big problem.” 

Transport Canada says recreational use of drones falls under the general guidelines against not endangering people or property. Breaking those rules can bring a fine of up to $25,000, though no one has ever been prosecuted, according to a spokesman for the federal agency. 

Transport Canada is working on introducing more specific rules, the spokesman said. 

From a report by the CBC's Lorenda Reddekopp and Genevieve Tomney