In Austin, an air traffic controller shortage prompted the FAA to issue a ground stop, causing more than 150 flights to be delayed. "Flying is no longer fun," one traveler said.

The Federal Aviation Administration is investigating another radio outage at the troubled air traffic approach control facility responsible for flights approaching and departing Newark Liberty International Airport.

Airport officials called it a "brief limited-scale ground stop" issued by the Federal Aviation Administration after a "reported possible security issue."

A ground stop has been issued at Hartsfield-Jackson Atlanta International Airport on Sunday. The Federal Aviation Administration said the ground stop was placed at 10:40 a.m. due to an equipment outage and is expected to last until noon. Officials said all inbound flights are being held at their origin until noon.

Something similar happened recently at Dallas/Fort Worth International Airport, when a safety incident forced authorities to check the aircraft and even issue a brief ground stop. While it appears that this was just a case of misunderstanding,

according to the Federal Aviation Administration. The ground stop at DIA started at 4 p.m. and was lifted by 6:20 p.m., the FAA said on its website. More than 700 flights are delayed or canceled ...