United Airlines briefly grounds all flights in US, Canada for second time in two months

United Airlines briefly grounded all mainline flights in the United States and Canada for about an hour Wednesday after the carrier asked the Federal Aviation Administration to pause departures at U.S. and Canadian airports. The move effectively halted departures across United's network before operations were restored, the airline said.

The stoppage marked the second time in two months that United has temporarily halted all of its mainline departures. The airline attributed the disruption to a brief connectivity issue just before midnight Central time on Tuesday, with operations resuming shortly thereafter. As of Wednesday morning, neither United nor the FAA had publicly acknowledged the stop on their official social media accounts, and the carrier did not provide updates beyond its initial statement.

"United experienced a brief connectivity issue just before midnight Central time on Tuesday, but has since resumed normal operations," a United spokesperson told FOX Business.

In August, United said a glitch caused grounded flights across major U.S. airports, including Newark Liberty International, Denver, Houston and Chicago, leading to widespread delays across its network. The outage at that time was resolved within a few hours, underscoring a pattern of intermittent disruptions that have affected the airline's operations in recent weeks.

Ground stops are a process that requires 'aircraft that meet a specific criteria to remain on the ground,' the FAA's website explains. They can be airport-, airspace-, or equipment-specific and are intended to manage traffic flow and safety. The traffic-management initiatives typically occur with little to no warning, according to the FAA, and can ripple through hubs and feeder networks as flights await clearance to depart or land.

Travelers faced confusion and delays as the system recovered, with lines for luggage and shifting gate information reported at major hubs. The abrupt pauses and subsequent resumption disrupted schedules during a peak travel period, testing customer patience and airline staffing decisions as crews and equipment rotated across airports.

The episodes come as United works to maintain reliability amid a busy summer and a network that has historically stretched from Newark and Chicago to Denver, Houston and San Francisco. While a one-hour ground stop does not appear to have caused long-term network-wide outages, the incidents add to ongoing questions about the resilience of United's IT and operational infrastructure and the speed with which the airline can recover from intermittent connectivity glitches.

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