The Federal Aviation Administration Wednesday grounded all United Airlines flights in the U.S. due to an unspecified problem with the carrier's computer system.
The FAA lifted the ground stop at 8:47 a.m. Central Time, saying the issue had been resolved.
It is the second time in as many months that United flights were delayed because of a computer glitch. About a month ago, United Airlines held flights for about 40 minutes when their dispatch system went off line.
Word that United flights had ceased first spread on Twitter, with many passengers reporting they had been delayed.
According to the advisory issued by the FAA, it issued the ground stop at the request of United. The first stop was issued at 7 a.m. Central Time for an hour and 15 minutes and included all United flights. The FAA then released United's sub-carriers from the ground stop, but then extended it for mainline United flights until 9:15 a.m. Central Time.
It issued an advisory canceling the ground stop at 8:47, saying the issue was resolved.