Late Friday, major US carriers said they were resuming operations after the FAA lifted the ground stop, but warned that delays and cancellations would continue as aircraft and crews were repositioned.

Delta said it was "safely resuming operations," but cautioned that it would take time to reset its network. Southwest said it would resume a limited number of flights after consulting with the FAA and would also focus on repositioning its operations for Saturday morning. United said it had resumed some flights Friday night.

JetBlue said it expected disruptions to extend into Saturday after canceling all of its remaining Friday flights, except Europe-bound flights from JFK and Boston.

American said it was focused on operating as many remaining flights as possible on Friday evening while positioning the airline for a recovery in the days ahead.

Most major US carriers issued travel waivers allowing eligible passengers to change or rebook flights under carrier-specific terms.