Second nationwide US flight halt since 9/11: how the November 13 FAA ground stop compares with September 2001 and January 2023

The FAA’s order on Friday, November 13, 2026, to halt all departing flights across the US is only the second nationwide stop of departures since the September 11, 2001, attacks. The three events had very different causes, and they played out on very different scales.

September 11, 2001

At 9:25 a.m. ET on September 11, 2001, the FAA banned takeoffs of all civilian aircraft regardless of destination, the first national ground stop in US aviation history. After a third hijacked plane struck the Pentagon, the FAA ordered all aircraft at 9:45 a.m. to land at the nearest airport as soon as practical. More than 4,500 aircraft were in the air at the time.

By shortly after noon, the airspace over the 48 contiguous states was clear of commercial and private flights. The Department of Transportation reopened national airspace to commercial and private aviation from 11 a.m. ET on September 13, with flights resuming case by case as airports put stricter security measures in place.

January 11, 2023

The FAA’s Notice to Air Missions (NOTAM) system, which gives pilots safety notices about hazards such as runway closures, failed overnight. The FAA ordered airlines to pause all domestic departures until 9 a.m. ET while it validated flight and safety information.

Departures resumed first at Newark and Atlanta, and at 8:50 a.m. ET the FAA said the ground stop had been lifted. The halt lasted about 90 minutes, Reuters reported. More than 10,000 flights were delayed and over 1,300 cancelled that day, according to FlightAware.

A preliminary FAA review found that contract personnel had unintentionally deleted files while working to correct synchronization between the live primary database and a backup database. The agency said it found no evidence of a cyberattack.

A smaller outage in September

On September 21, 2026, a telecommunications outage forced ground stops or ground delays at Newark, JFK, Philadelphia, LaGuardia and Teterboro airports. The outage hit a circuit at the FAA’s Philadelphia TRACON, the facility whose controllers guide aircraft approaching and departing the area’s airports, USA Today reported.

Transportation Secretary Sean Duffy said in a post on X that an Amtrak construction crew had accidentally cut a fiber line in New Jersey. Amtrak said it was not responsible. Duffy said the lines were repaired and the ground stops lifted at around 6 p.m. ET.

November 13, 2026

Friday’s nationwide stop followed what the FAA called “a temporary telecommunications outage.” Duffy said in a post on X that the communication issue was affecting all Air Route Traffic Control Centers, the 22 regional centers that direct planes en route between airports. Flights already in the air were allowed to land, but departures were halted “until further notice,” according to the FAA notice.

Homeland Security Secretary Markwayne Mullin told reporters at the White House there was no indication of an attack and said there was no timeline for restarting flights. No cause had been confirmed at the time of publication.

How the three compare

In 2001, the FAA cleared the skies entirely after a terrorist attack and kept national airspace closed for about two days. In 2023, a damaged database file paused domestic departures for about 90 minutes, with no evidence of a cyberattack. In November 2026, a telecommunications outage at the en route centers halted departures nationwide while airborne flights landed. Officials said there was no sign of an attack, and no restart time had been given.

Sources: FAA historical perspective (Chapter 9), National Archives, PBS NewsHour (2001), FAA NOTAM statement (2023), Reuters (2023), USA Today (September 2026), FAA on X, AP, BBC, CBS New York

Featured image: Air route traffic controllers at work at the FAA’s Washington Air Route Traffic Control Center. File photo: Federal Aviation Administration / Wikimedia Commons, public domain