美国航班停飞：FAA持续4小时故障致7000多架次航班取消内幕US flights grounded: Inside the 4-hour FAA outage that cancelled 7,000+ flights

The United States Federal Aviation Administration (FAA) lifted a nationwide ground stop Friday, November 13, after a communications failure at air traffic control centres disrupted flights across the country, forcing departing aircraft to remain on the ground for more than four hours.

The shutdown began at 3:54 pm Eastern Time (2:24 am IST on November 14) and was lifted at 8:15 pm ET (6:45 am IST), according to Transportation Secretary Sean Duffy. Although flights began resuming, airlines warned that the disruption could continue for days as aircraft and crew members were left out of position. A worker empties trash bins at Washington Dulles International Airport, in Chantilly, Friday after the Federal Aviation Administration grounded flights nationwide. (AP)

How did a communications failure bring flights across the US to a halt? What went wrong inside the air traffic control network, and why did the disruption continue after the FAA reopened the airspace? Our interactive graphic takes you through the shutdown, scene by scene, explaining what happened, why it happened and what comes next. More than 2,500 flights were cancelled in the United States on Saturday, with hundreds more delayed, news agency Associated Press reported. On Friday, over 4,700 flights were cancelled and around 10,000 delayed, news agency Reuters reported, citing FlightRadar24 figures.

The incident was the second nationwide ground stop since the September 11, 2001, attacks, t he report added. It has also renewed scrutiny of the ageing technology used to manage US air traffic and the challenges facing the government’s modernisation programme.

Express InfoGenIE · The day America stopped flying · 1/8 The day America stopped flying At 3:54 pm ET on November 13, the FAA held every departing flight in the United States on the ground.

It stayed that way for more than four hours. Times are US Eastern Time (ET) with India Standard Time (IST). The airport scene is an illustration. 1 2

3 4 5 6 7 8 Chapter 1 of 8 · Ground stop Next: First warning Friday, November 13, 2026 Every departure, frozen STOP All departures held 3:5234 PM ET Tap: planes already flying? Play scene↻ Replay↻ Replay Illustration · red stop-bar lights hold aircraft short of the runway Already in the air?

Keep going and land The order held departing flights on the ground. Aircraft that were already airborne were allowed to continue to their destinations and land. 3,500+aircraft in the air when the instability began, said Transportation Secretary Sean Duffy 3,000+flights landed safely during the disruption, said Homeland Security Secretary Markwayne Mullin Inbound international flights were to be managed case by case, the FAA said.

Close ×Ground stop issued3:54 pm ETFri, Nov 13 · 2:24 am IST, Sat, Nov 14 Ground stop lifted8:15 pm ETFri, Nov 13 · 6:45 am IST, Sat, Nov 14 How long departures were held

0123456789hr01234567890123456789min 3:36 to 3:54 pm ET: radar and radio instability3:54 to 8:15 pm ET: ground stopAfter 8:15 pm ET: delays and cancellations into Saturday The stop and the disruption are not the same. The ground stop lasted 4 hr 21 min. Cancellations and delays carried on into Saturday as airlines repositioned aircraft and crews. Sources: FAA statements; Sean Duffy and Markwayne Mullin, White House briefing, Nov 13, 2026; AP. Next in this story: First warning FAA statements (Nov 13, 2026); White House briefing by Transportation Secretary Sean Duffy and Homeland Security Secretary Markwayne Mullin (Nov 13, 2026), transcript via Roll Call Factba.se; AP. Updated November 14, 2026. Created by Aniruddha Dhar

What happened: How did the FAA ground stop unfold? The trouble began around 3:36 pm ET on Friday, when air traffic control centres experienced instability in radar and communications systems, Duffy said.

The Green family, from left, Charlie, his son Gavin, wife Paige MacWilliam and son Eli wait inside a terminal as flights are delayed at Seattle-Tacoma International Airport on Friday, in Seattle. (AP Photo) These facilities coordinate aircraft travelling between different parts of the country. The problems also affected Terminal Radar Approach Control facilities, or TRACONs, which manage aircraft approaching and departing airports.

Duffy said controllers began receiving inconsistent data from older switches and routers. Although communications and radar capabilities were not completely lost, the instability made it difficult for controllers to reliably communicate with pilots and track aircraft.

The FAA issued a nationwide ground stop at 3:54 pm ET, directing departing flights to remain on the ground until further notice. The agency described the decision as necessary under extraordinary circumstances and for safety reasons.

Express InfoGenIE · The day America stopped flying · 2/8 18 minutes: from first warning to ground stop Radar and radio problems were detected across the country before the FAA halted departures. Radar and network visuals are illustrations, not actual radar data or failure locations. 1 2 3 4 5

6 7 8 Chapter 2 of 8 · First warning Next: Airport chaos The first warning Radar and radio start to falter SIGNAL INTERMITTENT 15:36 ET Play scene↻ Replay↻ Replay Illustration · not actual radar data 3:36 pm ET · 2:06 am IST, Nov 14Instability in radar and communications is detected across air traffic control centres and TRACONs, Duffy said. Controllers began receiving inconsistent radar data. 18 minutes later 3:54 pm ET · 2:24 am IST, Nov 14The FAA issues a nationwide ground stop. The failure spreads

Duffy described instability “across the country”. Duffy said the communication issue affected all Air Route Traffic Control Centers, the regional centres that handle traffic between airports. Play scene↻ Replay↻ Replay Illustrative network. Dots and lines do not represent specific air traffic facilities or the links that failed; officials have not said which ones were affected.

En route centresTap to explainTRACONsTap to explain En route centres (ARTCCs) Air Route Traffic Control Centers are regional centres that guide aircraft at high altitude as they travel between different parts of the country. Close ×TRACONs Terminal Radar Approach Control facilities manage aircraft approaching and departing airports. Close ×Sources: Sean Duffy, White House briefing, Nov 13, 2026; FAA. Next in this story: Airport chaos Sean Duffy, White House briefing (Nov 13, 2026), transcript via Roll Call Factba.se; FAA; NPR. Updated November 14, 2026. Created by Aniruddha Dhar

More than 3,500 aircraft were in the air when the disruption began, Duffy said. Aircraft already airborne were allowed to continue to their destinations and land safely. International departures were handled on a case-by-case basis. The restrictions also affected international aviation. The European aviation agency suspended US-bound departures from its member states at the FAA’s request for several hours. Some flights across the Pacific, including those heading to Hawaii and Asia, were subsequently cleared to depart from San Francisco International Airport, according to the Associated Press.

Express InfoGenIE · The day America stopped flying · 3/8 Airport chaos: the numbers Thousands of flights were still due to leave when departures stopped. By evening, hundreds had been diverted.

Figures are from aviation analytics firm Cirium, as cited by Al Jazeera. The board is an illustration. 1 2 3 4 5 6 7

8 Chapter 3 of 8 · Airport chaos Next: Reopening Friday afternoon and evening The board turns red US DEPARTURESFRI · NOV 13 About this many still due to depart US airports after 4 pm ET01234567890123456789,012345678901234567890123456789ON TIMEBOARDINGDELAYEDSEE AGENTHOLDGROUND STOP Passengers on those flights (more than)1.5mBOARDINGBOARDINGDELAYEDSEE AGENTHOLDWAITING Flights diverted by 7:05 pm ET012345678901234567890123456789EN ROUTEBOARDINGDELAYEDSEE AGENTHOLDDIVERTED Returned to departure airport012345678901234567890123456789EN ROUTEBOARDINGDELAYEDSEE AGENTHOLDRETURNED Landed somewhere else012345678901234567890123456789EN ROUTEBOARDINGDELAYEDSEE AGENTHOLDELSEWHERE Play scene↻ Replay↻ Replay

Illustrative board · real figures 4 pm ET was 2:30 am IST on Saturday; 7:05 pm ET was 5:35 am IST. Where the diverted flights went 670 157 Returned to where they took offDiverted elsewhere What is a diversion?

Tap to explain Diversion A diverted flight lands somewhere other than its planned destination. Of the at least 827 diversions counted by Cirium by 7:05 pm ET, about four in five went back to the airport they had left. Close ×Source: Cirium, cited by Al Jazeera, Nov 14, 2026. Next in this story: Reopening

Cirium, as cited by Al Jazeera (Nov 14, 2026). Updated November 14, 2026. Created by Aniruddha Dhar At 8:15 pm ET, Duffy announced that US airspace had reopened. However, he warned that flights would resume gradually, depending on the availability of aircraft, pilots and flight attendants. “It’s going to be slow,” Duffy told reporters, urging passengers to check directly with their airlines. Express InfoGenIE · The day America stopped flying · 4/8

8:15 pm ET: the airspace reopens After 4 hr 21 min, the FAA lifted the nationwide ground stop. Getting back to normal would take longer. Times are US Eastern Time (ET) with India Standard Time (IST). Network and take-off visuals are illustrations. 1 2 3 4 5 6 7 8 Chapter 4 of 8 · Reopening Next: Inside the failure

Recovery The network comes back Ground stop lifted8:15 pm ETFri, Nov 13 · 6:45 am IST, Sat, Nov 14 Departures held for4 hr 21 minFrom 3:54 pm ET Departures resume · 8:15 PM ET Play scene↻ Replay↻ Replay Illustration Play scene↻ Replay↻ Replay Illustrative network. Dots and lines do not represent specific air traffic facilities or the links that failed; officials have not said which ones were affected. Back in the air is not back to normal Duffy warned that reopening the airspace would not mean an immediate return to normal. “It’s going to take us some time to get back to capacity,” he said. Why not? Tap to see What decides how fast flights resume 1Pilots available 2Flight attendants available 3Aircraft and crews out of position

“Does that mean every flight is going to fly right now? It’s going to be slow.” — “Do we have pilots and flight attendants available to fly your flight?”Sean Duffy, White House briefing. He told passengers to check with their airline.

Close ×Sources: FAA; Sean Duffy, White House briefing, Nov 13, 2026. Next in this story: Inside the failure FAA; White House briefing by Sean Duffy (Nov 13, 2026), transcript via Roll Call Factba.se; AP. Updated November 14, 2026. Created by Aniruddha Dhar

Why were US flights grounded? What caused the communications failure? The Trump administration blamed the outage on ageing air traffic control equipment that became overloaded as new technology was being integrated into the existing network.

A person looks at a flight information board at LaGuardia Airport in New York, Friday. (AP Photo)

Duffy said older switches and routers were overwhelmed by data, resulting in inconsistencies in the information reaching air traffic controllers. “Our switches, our routers actually got overloaded with data and they started to give us inconsistencies in the data from those routers and because of that we shut the system down,” Duffy said, according to Reuters. He said the system had not suffered a complete loss of radar or communications and that controllers had been able to land aircraft safely.

Homeland Security Secretary Markwayne Mullin said the introduction of new technology and security patches into the older network appeared to have overwhelmed parts of the system. CBS News reported, citing multiple sources familiar with the matter, that an update to the private communications network connecting the country’s air traffic control system had triggered a system reboot and communications outage. The network is operated by L3Harris Technologies, which did not immediately respond to the broadcaster’s request for comment. The precise technical trigger remained under investigation. Express InfoGenIE · The day America stopped flying · 5/8 Inside the failure: what officials have said

The FAA first called it a telecommunications outage. Hours later, officials blamed old equipment that could not cope. This is an official preliminary explanation, not a final technical finding. The precise trigger is under investigation. 1 2 3 4 5 6 7 8 Chapter 5 of 8 · Inside the failure Next: Cyberattack? What went wrong? Two explanations, a few hours apart

First: FAA, Friday afternoon“There has been a temporary telecommunications outage.”FAA post on X Later: White House briefingNewer technology and data overloaded old switches and routers. Duffy and Mullin, Friday evening Official preliminary explanationNot a final technical finding. Tap each step for what officials said. Step 1New technology and data+ Step 2Legacy switches and routers overload+OVERLOAD Step 3Intermittent communications and radar gaps+ Step 4Nationwide ground stop+ Play scene↻ Replay↻ Replay Step 1: New technology and data Mullin said the new equipment “was overwhelming the older system” as the FAA was “putting patches into the system”. “The patchwork doesn’t work,” he said. Markwayne Mullin, Homeland Security Secretary

Close ×Step 2: Legacy switches and routers overload “We have old switches, old routers. We use 1980s little copper lines… It got overloaded.”Sean Duffy, Transportation Secretary Close ×Step 3: Intermittent communications and radar gaps From 3:36 pm ET (2:06 am IST), controllers saw “instability for our radar and our communications” at centres and TRACONs, Duffy said. Sean Duffy

Close ×Step 4: Nationwide ground stop The FAA halted departures at 3:54 pm ET. “Our new IP switches did not go down; it’s the old hardware that went down,” Duffy said. Sean Duffy Close ×Also reported, not confirmed by officials CBS News, citing multiple sources, reported that an update to the private communications network linking the air traffic control system triggered a reboot and outage. The network is operated by L3Harris, which did not immediately respond to CBS News.

Sources: FAA; Sean Duffy and Markwayne Mullin, White House briefing, Nov 13, 2026; AP; CBS News. Next in this story: Cyberattack?

FAA post on X (Nov 13, 2026); White House briefing by Sean Duffy and Markwayne Mullin (Nov 13, 2026), transcript via Roll Call Factba.se; AP; NPR; CBS News. Updated November 14, 2026. Created by Aniruddha Dhar Was the outage caused by a cyberattack or the Microsoft disruption?

Mullin said officials had found no evidence that the outage was caused by a cyberattack or a rogue artificial intelligence system. He also said it was unrelated to the Microsoft service disruption that affected Outlook and other services on Thursday.

Reuters reported that the Department of Homeland Security had not ruled out either possibility while the investigation continued. Mullin said the National Security Agency was working with the department on the inquiry.

Duffy also said the FAA’s new AI-powered forecasting system was not connected to the failure.

Express InfoGenIE · The day America stopped flying · 6/8 Was it a cyberattack?

Three questions came up within hours. Here is what officials said, and what they have not ruled out.

Officials’ statements as of the White House briefing on Friday, November 13. The investigation is continuing. 1 2 3 4 5 6 7 8 Chapter 6 of 8 · Cyberattack? Next: The warning The cyberattack question Security check SECURITY CHECK · OFFICIAL STATEMENTS, NOV 13 > Cyberattack? NO EVIDENCE SO FAR

Microsoft link? NONE, MULLIN SAYS > AI tool? NOT CONNECTED > Investigation CONTINUING Play scene↻ Replay↻ Replay Tap each question to see what officials said. Was it a cyberattack??Was it linked to the Microsoft outage??Did the FAA’s new AI forecasting tool cause it?? No evidence so far “We’ve seen zero evidence that this was… a cyberattack,” Mullin said, adding that the National Security Agency was working with his department. He added that it “appears that this was mechanically driven; however, we’re still looking, so we’re not going to rule that out.”Markwayne Mullin, Homeland Security Secretary Close ×

No link, officials say “There is no connection between this and Microsoft,” Mullin said. Markwayne Mullin Close ×Not connected, Duffy says The SMART system “isn’t plugged in” to the core radar and automation systems, Duffy said: “There was no possible way SMART would have impacted what happened today.”

Its maker, Air Space Intelligence, also said the ground stop was not a result of the system. Sean Duffy; Air Space Intelligence, via NPR Close ×What is not known yet. Officials described the cause as preliminary.

Mullin and Duffy both said they were not ruling anything out while the investigation continues. Sources: Markwayne Mullin and Sean Duffy, White House briefing, Nov 13, 2026; NPR. Next in this story: The warning White House briefing by Markwayne Mullin and Sean Duffy (Nov 13, 2026), transcript via Roll Call Factba.se; NPR; Air Space Intelligence statement. Updated November 14, 2026. Created by Aniruddha Dhar The FAA lifted the ground stop only after testing its systems and confirming that they were stable and operations could resume, according to the agency. What is wrong with America’s air traffic control system?

The outage has highlighted the vulnerability of a US air traffic control network that still relies on ageing communications infrastructure, including legacy switches, routers and copper lines. Duffy said the country needed a much broader overhaul of its aviation technology to prevent similar failures.

The modernisation programme began last year after Congress approved $12.5 billion in funding. The FAA is replacing older copper connections with fibre-optic lines and upgrading radio, communications and other systems.

The White House and Transportation Department have sought another $30.1 billion to accelerate the upgrades, while Duffy has called for additional funding to complete the overhaul.

In September 2026, an eight-hour disruption affecting parts of the East Coast followed the failure of primary and backup data links at a Philadelphia air traffic control facility. Other incidents have affected Newark, Dallas and Denver. In January 2023, a failure in the FAA’s pilot-notification system forced a nationwide halt to domestic departures, Reuters reported. A September 2026 Government Accountability Office report had also warned about risks in the FAA’s modernisation programme, including the lack of an integrated schedule for thousands of projects and the possibility that poorly coordinated upgrades could disrupt air traffic control operations. The report did not predict Friday’s specific outage, but it highlighted the difficulties of upgrading a complex national system while keeping existing infrastructure operational.

Express InfoGenIE · The day America stopped flying · 7/8 The warning two months earlier A September report by the US Government Accountability Office said the FAA’s air traffic control overhaul lacked basic cost and schedule planning.

The GAO report did not predict the November 13 outage. It flagged risks in how the FAA is modernising the system. 1 2 3

4 5 6

7 8 Chapter 7 of 8 · The warning Next: Aftermath GAO report · September 14, 2026 11,389 schedules, no master plan 01234567890123456789,012345678901234567890123456789separate project schedules for phase one of the FAA’s overhaul, not integrated into a single master schedule Illustration · not actual schedules The report, Air Traffic Control Systems: Ambitious New Modernization Effort Needs to Improve Cost and Schedule Planning, covered the Brand New Air Traffic Control System programme.

No master scheduleTapNo reliable cost estimateTapClashing installationsTapAgeing systemsTap No master schedule The FAA has not built an integrated master schedule for phase one. It is working from 11,389 separate project schedules. Close ×No reliable cost estimate The FAA lacks a comprehensive, well-documented lifecycle cost estimate, raising the risk of overruns, delays and missed targets. Close ×Clashing installations Because projects are scheduled separately, installations are sometimes planned at the same sites, generally without schedules designed to limit disruption to controllers.

Close ×Ageing systems GAO reported in 2024 that over 75% of the FAA’s 138 air traffic control systems were unsustainable or potentially unsustainable. By May 2026, 2,560 of 5,170 copper wires, some dating to the 1960s, had been replaced with fibre. Close ×The timeline July 2025Congress appropriates $12.5 billion for the programme. The FAA is using most of it for phase one. September 14, 2026GAO publishes its warning. November 13, 2026Nationwide ground stop. December 2028FAA target to complete phase one.

Source: US Government Accountability Office, GAO-26-107992, Sept 14, 2026. Next in this story: Aftermath US Government Accountability Office, “Air Traffic Control Systems: Ambitious New Modernization Effort Needs to Improve Cost and Schedule Planning”, GAO-26-107992 (Sept 14, 2026). Updated November 14, 2026. Created by Aniruddha Dhar What’s next: When will US flights return to normal?

Although the FAA lifted the ground stop on Friday night, the disruption continued into Saturday as airlines struggled to restore their schedules.

More than 2,500 flights were cancelled in the US on Saturday, with hundreds more delayed, the AP report said. The cancellations came as aircraft and crew members remained at airports different from those where they were scheduled to operate.

Reuters reported that tens of thousands of passengers were stranded at airports across the country. Airlines, including American, Delta and United, were among those dealing with large numbers of cancellations.

The FAA and airlines are working to reposition aircraft and crews, rebook passengers and clear the backlog. Aviation analysts have warned that the disruption could take several days to fully unwind, even though the immediate technical problem has been fixed. Duffy said he expected the system to be operating normally in time for the Thanksgiving travel rush, one of the busiest periods for US air travel. Express InfoGenIE · The day America stopped flying · 8/8 After the ground stop: the long tail The stop ended on Friday night.

The disruption did not. The ground stop and the wider disruption are measured separately. The closing map is an illustration.

1 2 3 4 5 6 7 8 Chapter 8 of 8 · Aftermath Final chapter Saturday, November 14 Four hours of stoppage, a weekend of disruption

Ground stop 4 hr 21 min on Friday, 3:54 to 8:15 pm ET (2:24 to 6:45 am IST, Saturday) Knock-on disruption 3,000+ US flights cancelled on Saturday by about 5:45 am ET (4:15 pm IST), according to FlightAware data Bars show time, from 3:54 pm ET on Friday to the end of Saturday. Why it kept going 1Aircraft ended up at the wrong airports 2Crews were out of position

3Passengers missed connections and were rebooked Duffy said recovery would take time, but that the system would be operating normally for the Thanksgiving travel rush. Thanksgiving falls on November 26.

The bill for a fix $12.5bn Approved by Congress, July 2025, for phase one $30bn Requested by President Donald Trump, per Duffy $50bn What Duffy says he wants; Mullin put a full overhaul at about $50bn Play scene↻ Replay↻ Replay Can America’s aviation infrastructure keep up with its skies?

The FAA’s legacy systems support up to 45,000 flights a day, according to the GAO. The technical investigation into Friday’s failure continues. Illustration · aircraft depart again, then the view pulls back to the national network Sources: FlightAware; Sean Duffy and Markwayne Mullin, White House briefing, Nov 13, 2026; GAO. FlightAware data, via CNBC (Nov 14, 2026); AP; White House briefing by Sean Duffy and Markwayne Mullin (Nov 13, 2026), transcript via Roll Call Factba.se; Al Jazeera; GAO-26-107992 (Sept 14, 2026). Updated November 14, 2026. Created by Aniruddha Dhar Passengers whose flights were cancelled can seek free rebooking or a refund if they decide not to travel, AP reported. Travellers have been advised to check their flight status directly with their airlines. (With inputs from agencies)