Flights across US delayed due to system outage at FAA, says report

Over 400 flights were delayed within, into, or out of the United States as of Wednesday at 5:31 am ET, says the report

A U.S. Federal Aviation Administration (FAA) system outage is leading to delays at airports across the country due to 'ground stops', Austin-Bergstrom International Airport said on Wednesday.

The FAA said that it was working to restore a system that alerts pilots to hazards and changes to airport facilities and procedures that had stopped processing updated information.

"The FAA is still working to fully restore the Notice to Air Missions (NOTAM) system following an outage. While some functions are beginning to come back on line, National Airspace System operations remain limited," it said on Twitter.

More than 760 flights were delayed within, into, or out of the United States as of Wednesday 6:30 am ET, flight tracking website FlightAware showed, without citing the reasons.

An additional 91 flights within, into or out of the United States were also canceled.

A ground stop is an air traffic control measure that slows or halts aircraft at a given airport.

United Airlines said it had temporarily delayed all domestic flights and it would issue an update when it learned more from the FAA.

"Arriving and departing passengers can expect delays this morning and throughout the day," Austin-Bergstrom International Airport said on Twitter.

In an earlier advisory on its website, the FAA said its NOTAM system had "failed", although NOTAMs issued before the outage were still viewable.

A NOTAM is a notice containing information essential to personnel concerned with flight operations, but not known far enough in advance to be publicized by other means.

Information can go up to 200 pages for long-haul international flights and may include items such as runway closures, bird hazard warnings and construction obstacles.