CHICAGO (AP) — United Airlines has a new operations center in the tallest building in the U.S.

The airline gave the media a sneak peek Monday at its new network operations center that's housed on an entire floor in the Willis Tower. The center runs 24 hours a day, seven days a week with employees overseeing about 5,600 United and United Express flights a day. The center opened on May 31, combining operations centers from Houston and the Chicago suburb of Elk Grove Village.

About 1,300 people work shifts in the center, planning flights, forecasting weather, routing aircraft, scheduling crews and working with air traffic control from across the country.