CHICAGO (CBS) — Technical issues with a software system called Aerodata caused delays for several airlines nationwide Monday morning.

The Federal Aviation Administration told CBS News several carriers were “experiencing issues with a flight planning weight and balance program called Aerodata. Mainline operations and regional operations” were being “impacted to varying degrees.”

Southwest Airlines issued a ground stop for all its flights for about 40 minutes, due to a technology issue with a vendor that provides aircraft weight and balance data. The ground stop was lifted around 6:30 a.m., and flights were resuming with delays.

United Airlines also experienced computer problems, and said it was working to get passengers in the air as soon as possible.

Delta Air Lines, Alaska Airlines, and JetBlue also reported delays tied to a computer outage.

According to the Chicago Department of Aviation, only a handful of flight cancellations were reported Monday morning.

There were 23 cancelled flights at O’Hare International Airport as of 7:30 a.m., and 16 at Midway International Airport. It was unclear how many of those, if any, were related to the computer issues.