US airlines were hit on Monday by system-wide computer outages related to problems with the Aerodata planning weight and balance program, the Federal Aviation Administration (FAA) said.
There were delays at airports in Chicago, New York, Boston, Atlanta, Miami and Detroit. The FAA recommended people contact airlines directly for flight information and updates.
After reporting problems along with several major peers, Southwest Airlines said on Twitter it had received word that the problem had been resolved and that systems would be back up soon.
Southwest said it lifted an internal ground stop at 7.05am ET, after about 40 minutes. The airline anticipated scattered delays and said travellers should check its website for the updates on specific flights.
Earlier, carriers reported problems through their social media accounts, with United Airlines saying it was unable to create paperwork. The No 1 US carrier, American Airlines, said the outage was affecting regional carriers nationwide. Delta said some of its flights were impacted.
Canada’s Alaska Air said on its social media account it was experiencing a system-wide outage.