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... An incident involving two American Airlines flights near Phoenix early Friday "could have been disastrous," according to an air traffic controller who helped manage the situation.

Both planes were operating as American Airlines Flight 2482 " one traveling from Chicago to Phoenix and the other from Phoenix to Chicago.

The flights normally operate at different times, avoiding any conflict over the shared flight number. But the Chicago-to-Phoenix flight was delayed Friday, putting both planes in the same airspace at the same time.

Flight-tracking data showed the planes converging along the same path while separated by about 3 miles horizontally and 2,000 feet vertically, within legal separation requirements.

Air traffic controllers were aware that the two aircraft were using the same call sign. In recorded audio, controllers can be heard distinguishing between them by referring to one as "2482 on arrival" and the other as "2482 on departure."

"I've been working in air traffic for 25 years. I've never seen two aircraft pretty much merge with the same call sign. That's pretty incredible," one controller said. ...