Update: United Air lifts halt after computer failure grounded flights

[ATLANTA] United Continental Holdings Inc lifted a halt on domestic flights, ending a disruption that was caused by a computer failure.

"We have resolved the issue and flights are resuming,' Maddie King, a spokeswoman for the Chicago-based carrier, said by e-mail.

"Customers may experience additional delays as we work to get flights out this evening. We apologise for the inconvenience to our customers."

The third-biggest US carrier halted flights at about 5:30pm in Chicago. It was resolved by about 8:00pm, Ms King said.

United had 481 flight delays Sunday, or 26 per cent of its total daily flights within, into or out of the US, according to flight tracking firm FlightAware.com. That was the most of any US carrier, the website said.

A rash of computer failures disrupted flight operations at US airlines last year, stranding thousands of passengers as carriers struggled to keep older information systems working. Delta Air Lines Inc took a US$100 million hit to sales after a power-control module at the company's Atlanta command centre caught fire in August, cutting power to computers.

Southwest Airlines Co had to halt flights the month before that because of issues with "multiple technology systems".

At United, a 2015 computer issue prevented the carrier from ticketing passengers and dispatching crews, disrupting travel for thousands of fliers.

The domestic market accounts for about 60 per cent of United's sales, according to a report by Bloomberg Intelligence. The carrier serves more than 200 domestic airports with major hubs in Chicago, Houston, Washington and San Francisco, according to the company's website. United has about 4,500 departures throughout its global network.

Ground stops are relatively common reactions to thunderstorms and other disruptions in the US aviation system. They are typically short-lived and narrowly drawn, such as halting departures to a congested airport for an hour or two.

BLOOMBERG