NEW YORK -- Domestic flights were delayed across the country Wednesday due to an FAA system outage that impacted air travel nationwide.
The Federal Aviation Administration says its flight personnel alert system went down overnight.
The system alerts pilots and other flight personnel about hazards or changes to airport services, like runways closures or bird warnings.
All U.S. departures were delayed for a few hours, but the ground stop has since been lifted.
See live updates below for the latest.
More learned about what caused FAA outage
Transportation Secretary Buttigieg promises to find out "what steps are needed to make sure that it doesn't happen again"
Wednesday was not an ideal day for travelers, thanks to an FAA computer outage.
By midday, more than 1,000 flights were canceled, and 7,700 delayed, according to flight tracking website FlightAware.
That included our three area airports.
Flights were back up and running at Newark Liberty International Airport around 9 a.m. after the nationwide ground stop was lifted.
Still, travelers were arriving to learn their flights were impacted.
"I'm kind of frustrated, because I left the hotel very early in the morning from Manhattan. I tried to make it here with time, and finally we got here and just 10 minutes ago they sent me a text, delayed," said traveler Juan Mella.
"Did they tell you why it's delayed," CBS2's Jenna DeAngelis asked traveler Ava Yvonne.
"No. I didn't even get an alert," she said.
The FAA says the issue was an outage to its Notice to Air Missions system which provides safety information to pilots. The agency implemented a ground stop which Transportation Secretary Pete Buttigieg says lasted about an hour and a half.
"It is the right call to act out of an abundance of caution but no, these kinds of disruptions should not happen, and my primary interest now that we've gotten through the immediate disruptions of the morning is understanding exactly how this was possible and exactly what steps are needed to make sure that it doesn't happen again," Buttigieg said.
The ripple effect was being felt at airports across the country Wednesday, with thousands of flights canceled or delayed.
Around noon, fights still seemed to be impacted.
"We're going on a cruise today, so we hope we're not delayed too long. Right now, we're delayed for an hour, so we'll see what happens when we get upstairs," Gary and Sharon Swanson told DeAngelis. "We're trying to be cautiously optimistic."
So is flight expert Scott Keyes of Going.com, who had a prediction of what's to come.
"I'm hopeful that we're not going to see a major domino effect from today. I think we'll still see some number of delays and cancellations rolling into tomorrow, but that hopefully by Friday, and certainly by the weekend, things will mostly return to normal," Keyes said.
"I think it really underscores the need for more investment in some of the behind the scenes technology across the airline industry. Obviously, we're just coming off of a couple of weeks of the operational meltdown over at Southwest, caused by some of these similar tech meltdowns, and it seems as though that there might be something similar happening with technology and over at the FAA as well, causing widespread delays and cancellations," he added.
He has this tip for travelers.
"Under federal law, if an airline cancels or significantly changes your flight, you're entitled to a full cash refund if you choose not to travel. Even if the cause was outside of the airlines control, could be weather, could be an FAA issue like we saw this morning, you're still entitled to a full cash refund," Keyes said.
The FAA says it will continue to look into what caused it in the first place.
Travelers express cautious optimism after system gets back online
Flights are back up and running after delays and cancelations across the country following an FAA computer outage.
The stop order was lifted around 9 a.m., but there were some residual effects.
It was a headache for travelers, but those CBS2's Jenna DeAngelis spoke with were headed to their gates hopeful it won't be too long of a wait.
Chopper 2 captured grounded flights finally taking off at Newark Airport around 9 a.m. after the nationwide ground stop was lifted. But for hours, travelers came to the airport not knowing when they'd leave.
"We just got here, try to get on our flight over to Atlanta over to get to Equador, but if this delayed it might mess up our flight to Equador and we'll see what happens from there," travelers Suzanne and Jack Cruse told DeAngelis.
Early Wednesday, the Federal Aviation Administration's Notice to Air Missions system - or NOTAM - experienced an outage. That's a computer system that alerts pilots to hazards or changes to airport services like runway closures, or any warnings.
Around 10 a.m., almost 900 flights were canceled, nearly 5,000 delayed, including Gary and Sharon Swanson.
"We're going on a cruise today, so we hope we're not delayed too long. Right now, we're delayed for an hour, so we'll see what happens when we get upstairs," they told DeAngelis. "We're trying to be cautiously optimistic."
Travelers DeAngelis spoke with said they weren't informed why there was a delay at check-in. Juan Mella finally found out via text his flight to Tennessee was pushed back at least an hour.
"We're sorry for this delay," the text message read.
"I'm kind of frustrated, because I left the hotel very early in the morning from Manhattan. I tried to make it here with time, and finally we got here and just 10 minutes ago they sent me a text, delayed," Mella said.
Transportation Secretary Pete Buttigieg tweeted just before 9 a.m.
"The nationwide ground stop will be lifted effective immediately. I have directed an after-action process to determine root causes and recommend next steps," Buttigieg wrote.
Now that flights are back up and running, those DeAngelis spoke with are hopeful, if impacted, they won't be waiting too long and can get to their destination.
"We've been planning this trip for a long time," Alison and Pat Cavanaugh told DeAngelis. "This is our first trip alone since our honeymoon - 30 years or so."
It's not yet clear why it happened. In its latest update, the FAA said it will continue to look into the cause of the initial problem.
In the meantime, if you are flying Wednesday, keep in mind there could be lingering impacts.
Ground stop lifted
The FAA says normal air traffic operations are gradually resuming, and the ground stop has been lifted.
Travelers should check with their airlines for the latest.
CBS2 at Newark Airport
Jenna DeAngelis is at Newark Liberty International Airport, where more than a dozen flights are delayed.
Departures resume at Newark Airport
The FAA says it's making progress restoring its Notice to Air Missions system and departures are resuming at some airports, including Newark Liberty International.
They're expected to resume at other airports by 9 a.m.
FAA: Planes in the sky are "safe to land"
As departures remain delayed, the administration tweeted "all flights currently in the sky are safe to land."
Domestic flights delayed further
The FAA now tells CBS News that U.S. flight departures will be delayed until at least 9:30 a.m.
CLICK HERE for more from our national team.
FAA: Domestic flights delayed until 9 a.m.
The administration's latest tweet says it has ordered "airlines to pause all domestic departures until 9 a.m."
Newark tweets update to passengers
United delays all domestic flights
United Airlines released the following statement:
"The FAA system that sends out important real-time flight hazards & restrictions to all commercial airline pilots - Notice to Air Missions (NOTAM) - is currently suffering a nationwide outage. United has temporarily delayed all domestic flights and will issue an update when we learn more from the FAA."
American Airlines "closely monitoring the situation"
American Airlines shared the following statement:
"The Federal Aviation Administration is experiencing an outage with its NOTAM (Notice to Air Missions) system, which provides critical flight safety operation information. We are closely monitoring the situation, which impacts all airlines, and working with the FAA to minimize disruption to our operation and customers. We encourage customers to check aa.com for the latest flight information."
FAA tweet on the issue
Check your flight status
Use these links for the latest updates from local airports: