OTTAWA—A quick-thinking air traffic controller saved an ORNGE air ambulance helicopter from taxiing into the path of a landing Federal Express cargo jet at Ottawa airport.

The Transportation Safety Board of Canada has launched a formal investigation after the helicopter ignored a controller’s instruction and taxied into the protected area of a runway at Ottawa airport as the jet was preparing to land.

It was only a second instruction from the air traffic controller that stopped the ORNGE helicopter, callsign “Lifeflight 4,” in time, according to a preliminary report into the June 5 incident.

The incident is known as a runway incursion, a growing problem at Canadian airports and one that is on the safety board’s watchlist of serious transportation risks.

A Star analysis last year of Transport Canada data revealed that on average, there are almost 400 runway incursions by aircraft, vehicles and pedestrians each year at Canadian airports. A search of a Transport Canada database that logs aviation incidents shows there have been 175 runway incursions so far this year.

The Ottawa incident unfolded when the AW139 helicopter, preparing to depart to Pembroke, Ont., was told by air traffic control to stop its taxi before crossing Runway 25. However, the helicopter continued past the stop line and entered the runway’s protected area as the Federal Express Airbus A300 twin-engine jet was landing.

There was a “risk of collision” when the helicopter crossed the runway stop line without authorization and into the potential path of the arriving jet, according to a preliminary Transport Canada report into the accident.

“ATC (air traffic control) had to stop LF4 Medevac before it entered the runway,” the report says.

Chris Krepski, a spokesperson for the safety board, confirmed that an investigation is underway. He did not know how close the two aircraft got, saying that information would be sought as part of the investigation.

A spokesperson for ORNGE said the helicopter’s pilots reported the incident to the agency’s own safety team.

“We are conducting our own internal investigation in cooperation with Nav Canada, Transport Canada and the Transportation Safety Board. There was no damage or injury resulting from this occurrence,” Laurelle Knox told the Star in an email.