FAA Outage vs the 2023 NOTAM Failure: How They Compare

The nationwide ground stop on Friday, Nov. 13, 2026 kept every departing flight in the country on the ground for about 4 hours and 20 minutes. Only one recent event comes close to it in reach: the Jan. 11, 2023 failure of the FAA’s NOTAM system, which also froze departures across the whole country.

The FAA has not named the failed system on Nov. 13, so any cause comparison below covers what has been said, not what was found. The two events look alike on a departure board, but they are different stories. In 2023 a pilot-notice database failed in the middle of the night and was fixed within hours of the morning rush. In 2026 the FAA said a telecommunications outage affected multiple Air Route Traffic Control Centers, in the afternoon, with more than 3,500 planes airborne when the order came down.

If you need to know how the tool itself works, our explainer on what an FAA ground stop is and how it differs from a ground delay covers the terms. If your own trip was hit, the guide to refund and rebooking rights after an FAA outage covers what you can claim.

This comparison covers what failed, what was halted, how long it lasted, how many flights were hit, what caused it and what changed afterward.

It also sets both against September 11, 2001, the only time U.S. airspace itself was closed, so you can see where each event sits on the scale.

Flight counts below come from flight-tracking tallies, which move through the day and get revised, so read them as the size of each event and not as an official count.

What failed

The 2023 outage began with the Notice to Air Missions system, known as NOTAM. It is the database that tells pilots about closed runways, equipment outages and other hazards. It is a safety information feed, not the radio or radar link that controllers use to work with aircraft. When it failed late on Jan. 10 and a reboot did not fix it, the FAA ordered domestic departures held until the morning data could be trusted.

The 2026 failure sits in a different layer. Duffy said the problem affected “all Air Route Traffic Control Centers,” the facilities that guide aircraft between airports, and Homeland Security Secretary Mullin described “a telecommunication outage throughout the FAA.” The FAA’s own statement called it a “temporary telecommunications outage” and said flights were halted out of an “abundance of caution.” Mullin said there was “zero evidence” of a cyberattack and that the outage appeared to be “mechanically driven.”

What was halted

Both events stopped departures nationwide, which is why both are counted as nationwide ground stops. Neither closed the sky. In 2023 the FAA held all domestic departures until about 9 a.m. ET. In 2026 the Command Center advisory said all airports were ground stopped and that departing traffic should stay put “until further notice,” while inbound international flights were handled “case by case.”

The 2026 stop was not a clean freeze. After 6 p.m. ET the FAA said flights could leave through coordination with the Command Center, and Hawaiian and Alaska resumed some West Coast flights before the order was canceled at 8:15 p.m. Only one event in modern history shut the airspace itself: on September 11, 2001, every aircraft in the sky was ordered to land and none were allowed to take off.

How long it lasted

By the clock, 2026 was nearly three times longer. The order came at 3:53 p.m. ET and was canceled at 8:15 p.m. ET. The 2023 hold ended around 9 a.m. ET after roughly 90 minutes of halted departures, though the system had been down for hours before that.

How many flights were hit

FlightAware counted 4,467 U.S. cancellations and 10,079 U.S. delays by about 9 p.m. ET on Nov. 13, and Cirium put the total at more than 10,000 disrupted flights, with about 600 diverted. For the 2023 outage, flight-tracking tallies reached more than 1,300 cancellations and more than 11,000 delays by the end of the day.

The delay counts are close. The cancellation counts are not: 2026 produced more than three times as many cancellations, and its count was still climbing. JetBlue told staff it would cancel the rest of Friday’s flights except European routes, plus all Saturday flights, and delays and cancellations were expected into the weekend.

What caused it and what was disclosed

This is the one dimension where 2023 is far ahead. About a week after the outage, the FAA said a preliminary review found that contract personnel unintentionally deleted files while trying to correct a synchronization problem between the live primary NOTAM database and its backup. It found no evidence of a cyberattack or malicious intent, and it revoked system access for the personnel involved.

For 2026 the public record so far is three official statements and no root cause. Officials ruled out a cyberattack in plain terms, but the FAA has not named the failed system. Duffy said of the equipment that “It’s going to continue to fail.” Air Space Intelligence, the maker of the FAA’s new SMART routing tool, said the ground stop “is not based on or a result of the SMART system.” Homeland Security Secretary Mullin, asked at the White House whether SMART was being examined, said, “We’re looking at that,” and “You can’t rule out anything at this point.”

What changed afterward

The 2023 outage pushed the FAA to replace the legacy NOTAM platform. The agency moved toward a new cloud-based NOTAM Management Service and said it began operating in September 2025, with the rest of the legacy system to be retired in phases. That is the main reform that followed, and it is a data-system fix, not a change to how the FAA links its control centers.

Nothing equivalent exists for 2026 yet, because there is no named failure to fix. The ground stop follows other equipment problems, including the Newark radar outages and the ground radar outage at O’Hare, which makes the question of aging control-system equipment harder for the FAA to set aside.

What travelers are owed

The rules around refunds are not the same. The Department of Transportation’s automatic refund rule took effect on Oct. 28, 2024, so it did not apply in January 2023. It requires an automatic cash refund when an airline cancels or significantly changes a flight and the passenger declines the alternative. A significant change is a delay of three or more hours on a domestic flight or six or more on an international one, with refunds due within 7 business days for credit card purchases and 20 calendar days for other payments. It applies whatever the cause, so the FAA outage is covered. Travel credits are optional.

What the rule does not do is pay for hotels and meals when the cause is outside the airline’s control. Delta offered free changes for Friday and Saturday travel, and United waived change fees and fare differences for flights departing Nov. 12 to 20, 2026 on the same route and cabin. Visitors on the Visa Waiver Program who cannot leave because of an emergency can request up to 30 days of satisfactory departure under 8 CFR 217.3.

The verdict: which was bigger

By the numbers that matter to travelers, 2026 was bigger. It ran almost three times longer, hit the afternoon peak instead of a pre-dawn lull, and produced more than three times as many cancellations, with more expected. By the question of why, 2023 is the more complete story, because it has a named cause and a reform program.

Neither event is close to September 11, 2001, when airspace itself was closed. The fair reading is that Nov. 13 is the larger of the two nationwide stops and the less explained. When the FAA names the failed system, this comparison should be updated.

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