The Federal Aviation Administration on 9/11: All aircraft to land at the nearest airport as soon as practical. At the time, there were more than 4,500 aircraft in the air.
September 11, 2001, began as an ordinary day in the US air traffic control system. But that morning, the Federal Aviation Administration (FAA) would issue the first national ground stop in the nation’s history.
By 9:03 A.M., two hijacked planes had crashed into the World Trade Center’s North and South Towers. Responding to the attacks, the Federal Aviation Administration (FAA) issued the first national ground stop in the nation’s history – prohibiting departures for all civilian aircraft, regardless of destination.
Shortly after a third hijacked plane struck the Pentagon at 9:37 A.M, the FAA began the first ever unplanned shutdown of U. S. airspace, ordering all aircraft to land at the nearest airport as soon as practical. At this time, there were more than 4,500 aircraft in the air. At 11:06 AM, the FAA issued Advisory 036, which suspended operations in the National Airspace System.
Air traffic worked quickly to ground flights as the horrific events of the day continued to unfold, with the collapse of the North and South towers and crash of a fourth hijacked plane, United Airlines Flight 93, in Shanksville, Pennsylvania. By 12:16 P.M., three-and-a-half hours after the first plane hit, the airspace was clear of commercial and private flights.
A week later, the Director of Air Traffic Control issued a memo to all Air Traffic Control employees. He thanked the entire Air Traffic team for their strength, purpose, and dedication throughout the critical situation and their work to implement the national ground stop and clear the airspace. He recounts how two days later, “as we were all working through our shock and grief, we restarted the system – a little at a time, in accordance with national security interests.” The memo closes with the assurance that, “[W]e will recover and we will build a stronger and better system.” The events of September 11 changed the world. After the system restarted, air travel would never be the same.