A United Airlines computer fault that disrupted travel for thousands of fliers began with a router malfunctioning and prevented the carrier from ticketing passengers and dispatching crews.

Wednesday’s two-hour failure was separate from other recent digital mishaps, United spokeswoman Megan McCarthy said. But United’s persistent travails raise the prospect that customers may pick other carriers, according to consultants such as IdeaWorksCompany’s Jay Sorensen.

“This is not a weather problem catching everyone,” said Sorensen, a former Midwest Airlines executive. “This is something unique to a specific airline. Consumers are very upset and have zero patience when that happens and really expect the airline to bend over backwards in terms of compensation.”

Computer woes have been a recurring theme since the 2010 merger creating United Continental Holdings Inc. from former United parent UAL Corp. and Continental Airlines Inc. As recently as June 2, United had to suspend U.S. takeoffs for a little less than an hour after another computer failure.

The router malfunction affected computers at Chicago-based United including the Shares reservation system, said McCarthy, who didn’t have details on what other operations were involved. United fixed the issue in about two hours, by 10 a.m. New York time.

800 Flights

By then, travelers hustling for morning departures in the middle of the U.S. business week found themselves unable to take off, spawning delays that rippled across United’s system. United had about 800 tardy flights Wednesday, according to a spokeswoman, Jennifer Dohm.

That would be almost a third of United’s daily schedule, and the most in the global industry, based on data compiled by website FlightAware.com.

“I am more frustrated than anything,” said Jay Mitchell, an executive-search consultant who was booked to fly to Houston from Fort Lauderdale, Florida. A friend alerted him that United’s planes had been ordered parked, and he abandoned his trip to the airport.

“Almost half” of his United flights in the past two to three months have been delayed to some extent, said Mitchell, who flies almost weekly. “It’s gotten pretty consistent to where I now have to plan a buffer around my travel time.”

‘Minimal’ Fallout

United said affected travelers would be able to get a waiver to rebook trips without penalty. The carrier isn’t likely to feel much of a financial impact from Wednesday’s grounding, according to Bob Mann, a former American Airlines executive who now runs aviation consultant R.W. Mann & Co.

“For indefinite brief delays lasting from minutes to a few hours, there relatively little switching of carriers or cancellation of meetings, so the revenue loss is minimal,” Mann said.

United is no stranger to travelers dismayed by computer- related breakdowns. In 2012, Chief Executive Officer Jeff Smisek told analysts that some travelers “chose to fly other airlines” because of recurring disruptions during that year’s peak-summer travel season.

Wednesday’s grounding was similar to the incident on June 2, when the carrier cited a lack of “proper dispatch information” that forced a halt in U.S. takeoffs temporarily. Planes in the air weren’t affected in that episode either.

In February 2014, the system that handles check-ins and other passenger services failed, disrupting travel for about three hours at United hubs including San Francisco, Washington and Chicago. The previous month, a malfunction stranded pilots and caused about 1,500 cancellations.

United added extra precautions in 2012 after a computer breakdown caused one of its planes to take off about 20,000 pounds (9,100 kilograms) heavier than pilots believed, creating difficulties in getting the jetliner airborne.

Three other computer glitches that year at United also ensnared thousands of travelers with tardy flights.

–With assistance from Alan Levin in Washington and Mary Schlangenstein in Dallas.

This article was written by Michael Sasso and Lauren Thomas from Bloomberg and was legally licensed through the NewsCred publisher network.

Photo Credit: A United Airlines jet departs Seattle-Tacoma International Airport in Seattle. Elaine Thompson / Associated Press