A technical glitch caused flight delays across multiple U.S. airlines Monday morning.
A program called Aerodata, which monitors the weight and balance of planes, was down between 5:25 a.m. and 6:12 a.m., according to the Federal Aviation Administration
Southwest, United Airlines, JetBlue, Alaska and Delta were all experiencing residual delays due to the outage, the FAA said.
Airports in New York, Chicago, Washington, D.C., Atlanta and Dallas experienced the heaviest delays.
Both Delta and Southwest responded to customers on Twitter who were expressing their dismay with the travel disruption.
"It's affecting our flights system wide, and we're working to see if it's affecting any other carriers this morning as well. In the meantime, once more information has been made available our Agents at the airport will be happy to disseminate it to y'all," said a Southwest tweet.
Nearly 1,000 Southwest flights were delayed by noon Monday, according to flight tracking website FlightAware.
A Southwest statement said that the airline had lifted a ground stop of 7:05 a.m. that had lasted for about 40 minutes "during an outage with a vendor that services multiple carriers with data used in flight planning."
American Airlines, JetBlue and Delta also said in statements that the issue had been resolved, but residual delays could be expected. Delta's statement said the airline did not cancel any flights due to the "brief third-party technology issue."