American Airlines was forced to ground all flights in the US on Christmas Eve due to an unspecified technical issue.
The airline did not immediately say why it was stopping all flights, but social media was quickly abuzz with travellers worrying about getting to their loved ones for the holiday.
A groundstop notice was lifted not long after it was issued, but the possibility of disruption remains with so many flights needing to make up time.
Earlier on Tuesday, the airline said on social media: “An estimated timeframe has not been provided, but they’re trying to fix it in the shortest possible time.”
The Federal Aviation Agency said American Airlines was reporting “a technical issue and has requested a nationwide ground stop”.
In an update on Tuesday afternoon it said: “American Airlines reported a technical issue this morning and requested a nationwide ground stop. The ground stop has now been lifted.”
Passengers on social media reported having their flights stuck on the runway at various airports and being sent back to the gate.
American Airlines operates thousands of flights per day to more than 350 destinations in more than 60 countries.
It comes months after a faulty CrowdStrike software update led to worldwide flight cancellations.