A computer glitch causes havoc in the air in the United States

A computer glitch at the US Federal Aviation Administration (FAA) grounded flights entirely on Wednesday, with hundreds of cascading delays at airports across the country. The action is scheduled to last until 9 a.m. local time (3:00 p.m. in Spain)

As of 7 a.m. ET, there were more than 1,200 domestic flights delayed to and from the United States, according to flight-tracking website FlightAware.

More than 100 canceled flights

More than 100 have been cancelled. Most of the delays have been concentrated along the East Coast, but are starting to spread to the West. Airlines have begun delaying flights in response to the disruption.

The FAA said it is working to restore the air mission notification system. “We are performing final validations and reloading the system now,” the FAA said.

Operations throughout the national airspace system are affected. Some jobs are beginning to return to work, the agency said, but “national airspace system operations remain limited.”

Transportation Secretary Pete Buttigieg said in a tweet that he is in contact with the FAA. United Airlines said it is temporarily postponing all domestic flights and will issue an update as soon as it learns more from the FAA.

The FAA is working to restore what is known as the Air Mission Notification System. NOTAMs were once available via hotline, but have been phased out with the Internet.

Alerts range from mundane information about airport construction to urgent flight restrictions or malfunctioning equipment. There is a possibility of widespread power outages due to the outage.

All aircraft must pass through the system, including commercial and military flights. The agency said it will provide frequent updates as it progresses.