An air traffic controller’s quick thinking helped avert a dangerous situation late Thursday night when two American Airlines jets — one landing in Phoenix, Arizona, and the other simultaneously taking off — shared the same flight number and radio frequency.

The veteran air traffic controller realized that American Airlines Flight 2482 from Chicago that was coming in for landing at Phoenix Sky Harbor International Airport — and one that had just taken off and was headed for Chicago — were on converging flights and had the same call sign.

After catching the issue, the veteran air traffic controller began giving instructions to the pilots by differentiating their descriptions, using “American 2842 departing” and “American 2482 arriving.”

He was able to keep the aircraft separated, and both continued on their way without incident.

“I’ve been working air traffic for 25 years,” the air traffic controller told the pilots, according to dispatch audio recorded by ATC.com. “I’ve never seen two aircraft pretty much merge with the same call sign. That’s pretty incredible.”

He later added, “It could have been disastrous, but I’m glad it all worked out.”

The Federal Aviation Administration said the two planes maintained the required separation the entire time. The FAA said it is investigating the incident.

American Airlines told CBS News the situation was triggered because the flight arriving from Chicago O’Hare International Airport was delayed. That plane was supposed to land in Phoenix, take on new passengers, and then return to Chicago on the same callsign.

Because of the delay, however, a different aircraft was brought in so the waiting passengers in Phoenix could depart.

American Airlines said in a statement it was “reviewing the details related to two American flights with the same callsign.”

“The diligence and professionalism of air traffic controllers and our pilots ensured required separation was always maintained and the issue was identified and addressed,” the airline said. “Both flights continued safely and without incident.”