Why Are All Flights Grounded? The FAA Nationwide Ground Stop, Explained, and What It Means for Airline Stocks

Short answer: all U.S. flights are grounded because the FAA lost communications at its Air Route Traffic Control Centers, the 22 regional centers that guide planes between airports. Transportation Secretary Sean Duffy said the nationwide ground stop followed "a communication issue impacting all Air Route Traffic Control Centers" (Duffy on X, AP). The FAA later called it a temporary telecom outage and said all flights were halted as a precaution (FAA via FinancialJuice).

6:15 PM PT UPDATE (Nov 13, 2026): The FAA lifted the nationwide ground stop shortly after 8 PM ET Friday, about 5:15 PM PT. Reuters, the Associated Press, the Washington Post and WIRED reported the lift. Reuters calls it the longest nationwide shutdown since the September 11, 2001 attacks. It lasted more than four hours. At a White House briefing, Transportation Secretary Sean Duffy said the cause was an "incredibly old" legacy analog (TDM) telecom system. Switches and routers were overloaded with data and began giving inconsistent data, so the FAA stopped traffic. Homeland Security Secretary Markwayne Mullin said the problem came from putting software patches into the system as new equipment was being installed, and that the new technology overwhelmed the older system. Mullin said there is no evidence of a cyberattack or AI involvement, though officials are not fully dismissing a cyberattack. Duffy said communications and radar never fully went dark (a partial loss), and the updated digital centers did not have issues. Duffy is asking Congress for emergency funding, about $50 billion, for air traffic control improvements. He said he expects the system back to full operation before holiday travel, but that unwinding will take time. Reuters, citing FlightRadar24, says more than 4,700 flights were canceled and 10,000 delayed Friday, with about 700 already canceled for Saturday. Analysts say it could take days for airlines to restore schedules. Airline shares (UAL, DAL, AAL, JBLU, LUV and the JETS ETF) slipped after hours Friday. Monday's open is the first full session to price the cancellations and the weekend recovery. Cash markets were closed during the stop.

4:15 PM PT: The ground stop is still in effect. CBS News, citing multiple sources, reports that an update to the private communications network that links U.S. air traffic control caused the system to reboot and crash, which took down communications. That network is operated by L3Harris (LHX), which had not commented as of CBS's report. Microsoft says the ground stop does not appear to be linked to its services, and Nav Canada says traffic control measures at major Canadian airports were lifted after 6 p.m. ET with systems functioning normally. The FAA's national ground stop advisory is set to run until 8:30 PM PT unless it is lifted earlier.

UPDATE 3:15 PM PT: The ground stop is still in effect (FAA via FinancialJuice), but the FAA says that as its en route centers recover, flights will be allowed to depart in coordination with its command center (FinancialJuice). The FAA advisory runs the stop until 8:30 PM PT for now, subject to change (FAA advisory). CNN reports the outages hit air traffic control radar and radio frequencies (via FinancialJuice). On the cause, Homeland Security Secretary Markwayne Mullin said DHS, through CISA, is checking whether the FAA's new AI traffic tool, SMART, played a role (KPRC). The tool was expanded to all 22 en route centers on Tuesday, three days before the stop (New York Post). Mullin also said there is no reason to believe this was an attack and that he believes it was a software update (via Unusual Whales). Verizon says its network is working normally (via Bloomberg headlines). No official cause has been confirmed yet.

The stop hit just before 1 PM PT, about 3:54 PM ET, six minutes before the stock market closed. That means Wall Street has not had a full session with this news in it yet. The first real test for airline stocks is Monday's open.

What we know so far

• The FAA ordered all departing aircraft to stay on the ground "due to extraordinary circumstances and for reasons of safety" (AP, USA Today).
• Planes already in the air were not ordered to land immediately. International flights heading to the U.S. are being handled case by case (USA Today).
• The FAA said every flight is accounted for (FAA via FinancialJuice).
• Major airports including Atlanta, Reagan National, Miami, BWI and Houston Bush confirmed the stop (BBC).
• The National Weather Service separately reported nationwide internet and communication disruptions around the same time (NWS via FinancialJuice). Officials have not said whether the two are linked.
• As of about 2:10 PM PT, the FAA had not given a time for the stop to be lifted.
• As of about 3:15 PM PT, the FAA said departures will restart in coordination with its command center as centers recover, with no exact restart time.

Is it a cyberattack?

Not according to early reporting. CNN reported the ground stop does not appear to be a cyberattack (via Watcher.Guru), and the FAA described a temporary telecom outage. Homeland Security Secretary Markwayne Mullin said there is no cause for public alarm and that the president has been briefed (via FinancialJuice). He also said officials are not excluding any options at this stage, so treat "not a cyberattack" as preliminary until the FAA finishes its review.

It lands at the end of a rough week for critical systems. Microsoft's 365 and Outlook outage stretched across two days (our Microsoft outage page), and Google searches for "is there a cyber attack going on right now" were trending in the U.S. on Friday afternoon (Google Trends).

What happened last time: the January 2023 precedent

The closest comparison is January 11, 2023, when the FAA's NOTAM pilot-alert system failed and the agency paused all domestic departures until about 9 AM ET. More than 9,500 U.S. flights were delayed and more than 1,300 canceled that day (CNBC).

The stock reaction is the part traders should remember. Airline shares dipped in premarket, then rose during the session, with United up 3.9% that afternoon (WRTV/AP). A one-day federal outage that gets fixed fast has historically been a headline, not an earnings event.

The counterexample is a long tail. Delta's July 2024 meltdown after the CrowdStrike software failure ran for days, forced more than 5,000 cancellations, and cost the airline about $500 million (CNBC). Duration is what turns a scary headline into a real cost.

Airline stocks after hours

So far that is an orderly move, roughly 1.5% for the big carriers. The weekend matters more than tonight. Friday afternoon is one of the busiest travel windows of the week, so every hour the stop runs means more rebookings, crew timeouts and hotel bills that land on the airlines, not the FAA.

What to watch: if/then

• If the FAA lifts the stop tonight and gives a clear technical cause, the 2023 playbook says airline stocks can recover Monday. Watch whether JETS reclaims Friday's $28.84 close.
• If the stop drags into Saturday, expect cancellations to snowball the way they did for Delta in 2024. That is when JETS breaking under its after-hours $28.48 starts to matter.
• If officials link the FAA and Weather Service outages to one telecom provider, that provider's stock and network-security names become the story on Monday.
• If the cause turns out to be malicious, the move is no longer about airlines. Expect a risk-off open and a bid for cybersecurity stocks.
• If JetBlue (JBLU) keeps underperforming, it is the weakest balance sheet in the group and the most sensitive to a lost weekend.

FAQ

Why was the FAA ground stop lifted, and what caused it?

The FAA lifted the nationwide ground stop about 8:15 PM ET Friday. Officials blame data overload on an old analog telecom network after software patches during an upgrade. There is no evidence of a cyberattack so far.

Who runs the FAA's air traffic control communications network?

CBS News reports the private communications network that connects U.S. air traffic control is operated by L3Harris (LHX). Sources told CBS that an update to that network caused it to reboot and crash, leading to the nationwide ground stop. L3Harris had not commented as of that report, and the FAA has not published a final root cause.

Why are all flights grounded today?

The FAA issued a nationwide ground stop on Friday, Nov. 13, 2026, after a communications failure affected all of its Air Route Traffic Control Centers. The FAA called it a temporary telecom outage.

When will flights resume?

As of about 2:10 PM PT, the FAA had not given a time. Check your airline's app directly. In January 2023, the nationwide stop lasted about 90 minutes, but delays rippled through the rest of the day.

Is the FAA ground stop a cyberattack?

Early reporting says no. CNN reported it does not appear to be a cyberattack, and the FAA described a telecom outage. Homeland Security said officials are not ruling anything out yet.

How many nationwide ground stops have there been?

This is only the second nationwide ground stop since Sept. 11, 2001, according to the Washington Post. The other was the January 2023 NOTAM outage.

What does this mean for airline stocks?

Airline stocks were down about 1.5% to 3% after hours Friday. History says a short outage is a headline, while a multi-day disruption can cost an airline hundreds of millions. How long it lasts is the whole trade.

Did the FAA's new AI system cause the ground stop?

Not confirmed. DHS says it is looking at whether the FAA's new SMART air traffic tool, expanded to all 22 en route centers on Nov 10, played a role, and Secretary Mullin said he believes a software update was involved. The FAA has not named a cause.

Not financial advice. Flight counts, statements and after-hours quotes are snapshots as of about 2:10 PM PT Nov 13, 2026 and can change quickly. Nothing here guarantees any market outcome.

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Your call: Is this a one-night headline that airline stocks shrug off by Monday like January 2023, or the start of a Delta-2024-style weekend meltdown? Pick a side in the comments.