As per reports, a nationwide ground stop was issued for American Airlines due to an IT outage shortly after 1900 hours EDT (2300 hours UTC) on Tuesday (28 July).

• The temporary disruption affected all destinations and airports served by American Airlines across the US. The Federal Aviation Administration (FAA) confirmed that American Airlines had requested a nationwide ground stop after an IT outage affected the airline’s systems.
• During the disruption, aircraft already airborne were permitted to continue and land at their destinations. However, no American Airlines departures were permitted until the issue was resolved.
• As of approximately 1930 hours EDT (2330 hours UTC) on Tuesday (28 July), the airline confirmed that systems were coming back online, flights had resumed departures, and the temporary ground stop had been implemented while technical teams worked to restore operations.