Potential disaster was averted when a Phoenix air traffic controller recognized two American Airlines jets mistakenly were flying the same flight number and acted quickly to avoid confusion and keep them a safe distance apart. Audio of the incident shortly after midnight Friday shows how he found a solution to ensure the planes that were both called American 2482 maintained proper separation as one plane arrived from Chicago shortly after the other had taken off in Phoenix. Normally the same plane flies both legs of the round trip, but American employed a second plane after the flight out of Chicago was delayed. The incident will be investigated.