Alaska Airlines temporarily grounded its planes following an IT outage.
The carrier said it experienced the outage impacting its operations at around 8pm Pacific time on Sunday (4am Monday UK time).
It did not specify the nature of the outage.
“We requested a temporary, system-wide ground stop for Alaska and Horizon Air flights until the issue is resolved,” the Seattle-based airline said in a statement.
Horizon Air is the regional subsidiary operating Alaska Airlines flights.
Alaska Airlines apologised for the ground stop of its flights and resumed operations hours later, but warned of “residual impacts to our flights”.
It will take some time to get our overall operations back to normal,” it added in a social media post.
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Alaska Air Group maintains an operational fleet of 238 Boeing 737 aircraft and 87 Embraer 175 aircraft, according to its website.
In June, Hawaiian Airlines, which is also owned by Alaska Air Group, said some of its IT systems were disrupted by a hack.
The firm said it was still trying to determine the financial impact of the incident.
