United Airlines was forced to issue an urgent ground stop across its entire mainline fleet on Thursday night after a fire alarm sounded at its headquarters.
The move came just days after a similar Alaska Airlines ground stop caused hours-long delays for travelers across the United States.
Passengers who were already in the air at the time of the ground stop were warned to ‘expect some airborne holding due to excessive demand.’
The ground stop was lifted after about an hour, and a United spokesperson said: ‘A fire alarm sounded at our operations center, which caused employees to move to our nearby backup facility and resulted in a brief nationwide ground stop of United aircraft.
‘No flights were diverted, United Express regional flights [were] not affected.’
United operates the world’s largest fleet with more than 1,000 planes, all of which were temporarily placed on hold.
The order came just days after Alaska Airlines issued a similar ground stop which sparked hours of delays on Sunday night.
In that case, the airline issued requested the US Federal Aviation Administration stop all mainline flights across the United States due to a system-wide IT outage.
Both ground stops come amidst a turbulent time for the FAA after Trump fired as many as 400 employees as part of his vision to slim down the federal workforce.
Planes were grounded from around 8pm PT (11pm ET) before operations resumed again at 11pm PT (2am ET), Alaska Airlines said in a statement on Sunday.
The firm has as many as 238 planes in its fleet – all of which are Boeing aircrafts – and its biggest hubs include Seattle, Portland, LA and San Francisco.
Shortly after the initial request, a secondary order came through to extend the ground stop to subsidiary airline Horizon Air, which operates another 45 planes.
Alaska Airlines admitted the ground stop would cause delays for travelers and have knock on effects the following day.
‘At approximately 8 p.m. Pacific on Sunday, Alaska Airlines experienced an IT outage that’s impacting our operations,’ the airline said in a statement Sunday evening.
‘We requested a temporary, system-wide ground stop for Alaska and Horizon Air flights until the issue is resolved.’
The airline has warned of ‘residual impacts to our operation throughout the evening’ amid concerns about widespread travel delays.
One passenger revealed he and his fiancé spent two hours waiting on a tarmac in Denver before the flight crew finally instructed them that the plane would not be taking off.
At 10.30pm, all passengers were instructed to disembark and await further instruction, he said.
Another passenger, Riley Davis, said after two and a half hours on the tarmac, he still had no indication of when he would be free to deplane.
‘Since they cannot coordinate exact gates, they are manually assigning gates via radio communication,’ he revealed.
‘I would love to know when I can get some dinner, I’m starving.’
He was inundated with comments from other travelers who said they’d noticed tarmacs around the country blocked by Alaska Airlines planes which had nowhere to go.
