Alaska Airlines said the outage would lead to “residual impacts” to its operations overnight to its mainline fleet and the planes that fly under the Horizon Air brand.

Alaska Airlines grounded its entire fleet of planes and those of a subsidiary because of a software outage late on Sunday, the company said.

The airline first requested to ground the more than 200 aircraft it operates under the Alaska Airlines brand at about 11 p.m. Eastern time, according to an advisory released by the Federal Aviation Administration. The ground stop was then expanded to include planes from Horizon Air, a unit of Alaska Airlines.

“We requested a temporary, systemwide ground stop for Alaska and Horizon Air flights until the issue is resolved,” the airline said. “There will be residual impacts to our operation throughout the evening.”

Alaska Airlines said in late April that it was operating 238 planes, all Boeings, under its brand, and another