Two American Airlines Jets Shared the Same Flight Number Over Phoenix. A Controller Caught It in Time.

A Phoenix air traffic controller with 25 years on the job stopped a serious mess before it became one late Thursday night into early Friday morning, according to the Associated Press, when he caught that two American Airlines jets were flying with the exact same flight number at the exact same time in the same airspace.

Both aircraft were labeled American 2482. One was arriving from Chicago O'Hare International Airport, landing about 90 minutes late at 12:13 a.m. The other was departing Phoenix Sky Harbor International Airport for Chicago at 11:58 p.m. the night before, according to InsideFlyer. Same callsign. Same frequency. Converging flight paths.

Pilots take instructions based on callsign. If both crews believed a given instruction was meant for them, they could have ended up at the same altitude heading toward each other. The Associated Press, in reporting carried by the Sun-Sentinel, Chicago Tribune, Las Vegas Sun and Local10, noted it was "crucial they knew which plane he was directing."

The controller solved it on the fly. Audio captured by ATC.com and reported by CBS News shows him splitting the identical callsigns apart verbally, calling one "American 2482 on the arrival" and the other "American 2482 on the departure." He kept the arriving jet above the departing one as their paths crossed, made sure both flight crews had each other in sight miles out, and told the departing plane to hold its climb so a vertical gap stayed in place.

"I've been working air traffic for 25 years. I've never seen two aircraft pretty much merge with the same call sign. That's pretty incredible," the controller said, according to the recording. After the planes cleared each other, the arriving pilot radioed "nice work." The controller responded: "It could have been disastrous, but I'm glad it worked out."

How two planes ended up with one flight number

Flight 2482 normally runs as a single round-trip: one aircraft flies Chicago to Phoenix, then turns around and flies the same route number back. That's standard practice for a lot of short-turnaround routes.

But weather delayed the inbound jet from Chicago. Rather than make Phoenix passengers wait for that same late plane to turn around, American Airlines swapped in a different aircraft to fly the return leg on time, according to the Associated Press. That decision put two Boeing 737-800s in the sky simultaneously, both carrying the label American 2482.

The FAA said the two aircraft maintained required separation throughout the encounter and confirmed it is investigating, according to CBS News. American Airlines said in a statement that it is "reviewing the details related to two American flights with the same callsign," and credited its pilots and controllers: "The diligence and professionalism of air traffic controllers and our pilots ensured required separation was always maintained and the issue was identified and addressed. Both flights continued safely and without incident."

Where the actual failure happened

Steve Arroyo, an aviation safety expert who spent four decades at United Airlines starting as a dispatcher before becoming a pilot, told the Associated Press this almost certainly traces back to a dispatch-level oversight. Someone signed off on a flight plan without catching that two aircraft would share a callsign in the air at the same time.

"You can drop the ball and that shouldn't happen, but it's nice to see that the system is resilient and we have all the safeguards," Arroyo said. He noted he's only seen this specific type of duplicate-callsign conflict a couple of times in 40 years.

InsideFlyer raised a fair operational question the other outlets didn't dig into: standard practice calls for a modified callsign, like an added letter or suffix, when a duplicate flight number is going to be airborne at the same time as its counterpart. Whose job that is remains unclear. It could fall on airline operations, air traffic control, or some shared protocol between the two.

Nobody was hurt. No aircraft came close to actual contact, based on the FAA's own account of maintained separation. But scheduling failures that allow two jets to share a callsign in overlapping airspace are exactly what regulators examine closely, because they depend entirely on a controller catching the problem in real time rather than being blocked from happening in the first place.

The FAA has not released a timeline for its investigation. American Airlines has not said whether it will change how it assigns flight numbers to substitute aircraft during weather delays. Until one of those two things happens, the fix that worked that night was a controller's judgment call, not a system safeguard.