It is separate from the air traffic control system that keeps planes a safe distance from each other, but it’s another critical tool for air safety.
The FAA also operates the nation’s air traffic control system, with air traffic controllers using radar to track all planes in their air space and radio communications with their cockpits to guide them safely.
If no new problems crop up, flights should return to normal soon, though it may take time to get all the delayed flights in the air.
Just before noon ET Wednesday, tracking service FlightAware shows about 7,000 delayed flights to, from and within the United States, with nearly 1,100 canceled flights altogether.
But if the problem stretches too long, flight crews who are standing by to fly delayed flights will run out of time in their service day.