The incident occurred when one aircraft attempted to land at Portland International Airport while another had just taken off.

It took place around 4.15pm local time on Monday 16 October, during stormy conditions.

An Alaska Airlines flight from Orange County, California, aborted its attempted landing on an airport runway due to wind and reportedly turned towards the flight path of a SkyWest Airlines plane that had just lifted off from a parallel airstrip.

A controller can be heard telling the Alaska Airlines pilot to change course in air traffic control audio that has been made public by Live ATC.

Data shows that Alaska Airlines flight 1299 was travelling at 214mph, while SkyWest Airlines flight 3978 had reached a speed of 190mph.

An Alaska Airlines spokesperson said: "Due to inclement weather at Portland International Airport on Monday 16 October, Alaska Airlines flight 1299 from Orange County conducted a routine go-around during its initial approach to landing.

"There was another aircraft departing on the parallel runway to the north which created a potential traffic conflict.

"The crew of flight 1299 followed cockpit indications and reacted immediately to increase separation from the other aircraft."

The spokesperson added: "The aircraft maintained a safe amount of lateral separation throughout the entire event.

"Our aircraft then diverted to Redmond Airport due to the inclement weather. The flight later continued to its intended destination in Portland where it landed safely.

"The safety of our guests and employees is always our top priority, and consistent with that value, Alaska Airlines is internally reviewing this event."

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A spokesperson for SkyWest said: "We are aware of reports regarding SkyWest Airlines flight 3978, operating as Delta Connection from Portland to Seattle on Monday 16 October.

"The flight departed normally with pilots following air traffic control instructions and landed routinely at Seattle.

"At no point was the safety of the flight compromised."

The Federal Aviation Authority (FAA) said it will be conducting an investigation into the incident, in which it "will determine the closest proximity between the aircraft".