Duffy: Router in FAA contractor’s upgrade caused nationwide ground stop, not a hack; 5,000 more U.S. flights canceled Saturday

Live updates:  This story is being updated every 15 minutes.  Last updated 5:46 p.m. PT Saturday.

The Federal Aviation Administration lifted the nationwide ground stop at 5:15 p.m. PT Friday after restoring “full functionality” at its air traffic control centers, Transportation Secretary Sean Duffy said, ending a halt that had grounded departures for more than four hours, including at San José Mineta, San Francisco and Oakland international airports.  The stop followed a telecommunications failure at the FAA’s regional control centers, and it left thousands of canceled and delayed flights.  On Saturday, Duffy said the failure began when a router flooded the FAA’s network with traffic during routine work by its contractor, L3Harris, to replace aging copper lines with fiber at a remote FAA site, and that officials do not believe it was a cyberattack, according to Scripps News.  “It will take us time [to] resume normal operations,” Duffy said.  At 5:50 a.m. PT Saturday, Duffy said operations “are slowly returning to normal this morning” and that “it is safe to fly,” but warned travelers will “continue to see some delays and cancellations.”  At 10:28 a.m. PT, the FAA said “the system is stable and we’re returning to normal operations.”

Hawaii’s Transportation Department first reported the lift at 5:20 p.m. PT, and SFO confirmed at 5:30 p.m. that the stop had ended.  The FAA reposted Duffy’s statement at 6:02 p.m., and at 7:05 p.m. it said that “some flight departures are resuming” and that “before clearing flights to resume, we thoroughly tested our systems to confirm they were stable and that operations remain reliable.”  Its Command Center had posted no new advisory after one issued at 2:46 p.m. as of 9:55 p.m.  By 6 p.m., the FAA’s status page no longer listed any departure delays tied to the national stop; at 5:10 p.m. it had shown delays of about 3 hours at Atlanta and 5 hours at Chicago O’Hare.

Flights canceled and delayed

The flight-tracking site FlightAware counted 9,190 canceled flights and 7,470 delayed flights within, into or out of the United States on Friday.  At SFO it counted 519 cancellations and 412 delays, at SJC 102 cancellations and 98 delays, and at OAK 72 cancellations and 90 delays.  The disruption is spilling into Saturday:  as of 5:43 p.m. PT Saturday, FlightAware already counted 6,371 U.S. cancellations and 7,929 delays for Saturday, including 271 cancellations at SFO, 41 at SJC and 27 at OAK.  Those are tracker counts that include flights hit by other problems, such as SFO’s separate wind delays, not official totals.  Neither the FAA nor the airlines had released totals.

The nationwide stop has not returned.  A separate, much narrower ground stop that the FAA put on Delta flights bound for New York’s LaGuardia Airport at 12:47 p.m. PT Saturday was no longer listed on the agency’s status page at 3:40 p.m. PT, and the page showed no ground stops or ground delay programs anywhere in the country.  The FAA had listed the reason for the LaGuardia stop only as “other,” and neither the FAA nor Delta had explained it.

What caused it

At a Saturday news conference at Transportation Department headquarters that began at 7:51 a.m. PT, Duffy said the outage began during routine telecommunications maintenance at a remote FAA facility, where L3Harris, the FAA’s longtime telecommunications contractor, was replacing aging copper lines with fiber-optic service, according to Scripps News.  During the work, he said, a router began flooding the FAA network with traffic, generating more than 1,000 connection attempts every four to five seconds and disrupting communications.  Investigators have not yet determined whether the failure came from human error, an installation mistake or the equipment itself, and officials do not believe it was a cyberattack or other malicious activity, Duffy said.  The White House posted a clip of his update on the investigation.  FAA Administrator Bryan Bedford opened with an apology.  “I’d like to start with a sincere apology to the American traveling public,” he said.  “Tens of thousands of Americans had their flights disrupted yesterday and I want you to understand that we did that out of an abundance of caution.”  Bedford said the work at the remote site was routine upkeep of the FAA’s existing 1980s-era network, which the agency spends $1 billion a year maintaining, and “not part of the Peraton-FAA $12.5 billion modernization effort,” according to a White House clip.  “Every agency within the government for better than two decades has flagged this as a critical weakness,” he said.  “Let’s not kid ourselves:  it will continue to break until we replace it.”  Duffy said at 9:42 a.m. PT Saturday that, with $12.5 billion Congress provided as a “down payment,” 70% of the FAA’s telecommunications lines have been upgraded to high-speed fiber over the past year.

L3Harris said at 11:08 a.m. PT Saturday that it is “supporting the FAA in its investigation to understand the conditions that led to the Nov. 13 ground stop” and “takes the nationwide ground stop and its impact on travelers, airlines and air traffic operations seriously.”  The company said it, its telecommunications partners and the FAA have completed more than 70% of the planned switch from legacy copper wires to fiber.  It did not address Duffy’s account of the router.

On Friday, Duffy said in a 1:16 p.m. post that the stop followed “a communication issue impacting all Air Route Traffic Control Centers,” the regional centers that guide planes between airports, and that FAA technicians are investigating.  At 2:02 p.m., the FAA called it “a temporary telecommunications outage” and said all flights were halted “out of an abundance of caution.”  “Every flight has been accounted for,” the agency said.  An FAA advisory to its centers described a “nationwide comms failure.”  In a timeline posted at 6:15 p.m., Duffy said the telecommunications problems hit FAA facilities and approach-control centers across the country at 12:36 p.m. PT, while more than 3,500 planes were in the air.  Pilots and controllers landed them using established procedures, bringing the number in the airspace to under 400 by 5 p.m. PT, he said.  “The FAA confirms they did not lose all radar or telecom,” Duffy wrote, and medevac, “life-saving cargo” and law enforcement flights were allowed to keep flying.

Homeland Security Secretary Markwayne Mullin told reporters shortly after 2 p.m. that “there is no indication as of yet that this was a nefarious attack.”  “Everybody is safe,” Mullin said.  “There is no reason to be concerned about your loved ones if they’re flying.”

Pressed by reporters, Mullin did not rule out a cyberattack.  “As we investigate what caused this, you always got to assume that as many cyberattacks that take place that you make that assumption,” he said, according to The Hill.  “But as of right now, that’s not known.”  He said the first priority is to restore communications and get flights back to normal, and that the government will keep working “to find out what the root of the cause is.”  At 6:25 p.m., Duffy blamed the age of the system.  “Today’s nationwide ground stop happened because our air traffic control system is operating on DECADES-OLD, analog equipment that simply cannot compete with the demands of the 21st century,” he wrote, and urged Congress to pass funding for a new system.  At a White House briefing that began about 5:30 p.m., Mullin said “there is nothing that indicates a cyberattack as of right now,” but that officials are “not ready to completely rule it out,” according to a White House post of his remarks.  “We have seen zero evidence that this was a cyber attack,” he said in a clip posted by Homeland Security.  Mullin also called the aging system “a national security risk,” in a clip posted by Homeland Security, and blamed Congress for not making it a priority.  Duffy used the briefing to press for money to replace the system.  “What we have is an incredibly old air traffic control system,” he said in a White House clip, adding that the president has been asking Congress to fully fund a new one.  At the White House briefing, Duffy said switches and routers on the FAA’s analog air traffic control system became overloaded with data, causing inconsistent communications, and pointed to time-division multiplexing, a dated, mostly copper-wire technology that carries controllers’ voice and radar data, according to the Los Angeles Times.  “It’s an old system that went down and went down everywhere,” he said, and he said there was no evidence of a cyberattack or the involvement of foreign adversaries, the Times reported.  Duffy called on Congress for $50 billion for a “complete overhaul” of the system, The Hill reported.  In a Homeland Security summary of the briefing, Mullin is quoted as saying “the President has declared this a national emergency” and that the department has brought in “all of our assets,” including the Cybersecurity and Infrastructure Security Agency, and that the “NSA is working with us.”  The FBI and CISA had posted nothing about the outage on their own X accounts.

How long until things are back to normal

Lifting the stop does not mean flights are back to normal.  Duffy said Friday it “will take us time.”  At 5:50 a.m. PT Saturday he said operations “are slowly returning to normal,” with planes “pushing back, taxiing, and taking off,” and that delays and cancellations will continue “as carriers reschedule flights and reposition aircraft/crews where they are needed most.”  He said the department is “in close coordination with the airlines to support the ongoing recovery” and scheduled a press briefing for 10:30 a.m. ET (7:30 a.m. PT) Saturday at Transportation Department headquarters.  At that briefing, which began at 7:51 a.m. PT, Duffy thanked controllers and pilots for safely landing the 3,500 aircraft that were in the air and urged Congress to fully fund air traffic control modernization.  The FAA, quoting Duffy’s post at 6:13 a.m., thanked travelers for their “continued patience as operations return to normal” and told them to check flight status with their airline.  At 9:57 a.m. PT, FAA Administrator Bryan Bedford said the agency is still working “to recover operations.”  At 10:28 a.m. PT, the FAA said “the system is stable and we’re returning to normal operations,” and asked for patience “as our airline partners work to get you to your destination.”  As of 11:19 a.m. PT, neither the FAA nor the department had posted a time when operations will be fully normal.  Its Command Center said it is releasing traffic “as conditions allow” in “a tiered approach,” letting more flights go as limits ease.  The original order, issued at 12:54 p.m., grounded departures “until further notice.”  At 11:15 a.m. PT Saturday, the FAA’s status page showed no ground stop or delay program at SFO, SJC or OAK; a separate wind-related ground delay program at SFO that had averaged more than two hours was no longer listed.  With planes and crews out of position after the stop, delays and cancellations are spilling into Saturday.  American Airlines said at 7:30 p.m. that it is “positioning the airline for the strongest possible recovery in the days ahead,” and JetBlue said it expects “disruptions to continue into tomorrow, including additional cancellations.”  Before the nationwide order, the FAA had stopped flights at Chicago’s O’Hare and Midway airports starting about 12:10 p.m. because of an equipment outage.

What airlines are doing

• Delta:  At 6:21 p.m., Delta said the ground stop “has been lifted and we are safely resuming flights,” and told customers to check the Delta app or delta.com for flight status.  Earlier, at 3:44 p.m., it said a travel waiver lets customers change flights “at no extra cost.”
• United:  At 8:44 a.m. PT Saturday, United said “most United flights this weekend are operating normally” after the ground stop, but that “some flights will continue to be delayed or canceled as we work to restore our aircraft and crew schedules.”  On Friday at 6:56 p.m., United said the ground stop “has lifted” and that it “is resuming operations, including some Friday night flights,” as it works “to restore our full schedule.”  Earlier, at 2:30 p.m., it said travelers can check or rebook at united.com or in its app.
• American:  At 11:22 a.m. PT Saturday, American said Friday’s nationwide ground stop “led to significant disruption across our operation” and encouraged customers traveling Saturday “to monitor their flight status and view their latest rebooking options on the American app.”  On Friday at 7:30 p.m., American said the stop “has been lifted” and that it is “focused on operating as many remaining flights as possible this evening,” and it urged customers to check their flight status.  Earlier, at 4:53 p.m., it said it expected “unavoidable cancellations.”
• Alaska and Hawaiian:  Hawaii’s Transportation Department said at 3:05 p.m. PT that Hawaiian and Alaska Airlines “have confirmed all west coast flights will resume.”
• JetBlue:  At 5:08 p.m., JetBlue said it is canceling all remaining flights Friday evening except Europe-bound departures from New York’s JFK and Boston, and that fee waiver and rebooking options are on jetblue.com and its app.
• Southwest:  Southwest had not posted a general statement on X about the stop as of 4:59 a.m. Saturday.  Check its app for your flight.

Under Transportation Department rules, if your flight is canceled or significantly changed and you choose not to travel, the airline must refund your ticket, even when the cause is outside its control.  Airlines are not required to pay for hotels or meals when the government grounds flights, but some offer them, so ask.

At Bay Area airports

San José Mineta International Airport said at 5:50 p.m. that the FAA has lifted the stop and told travelers to “expect delays to continue as airline operations ramp back up to normal.”  SFO said at 5:30 p.m. that it “is reverting back to normal operations.”  Earlier, at 3 p.m., SFO had cleared Pacific-bound flights, including to Hawaii and Asia.  SFO is also under a separate wind-related delay program, according to the FAA’s status page.  Oakland airport said at 4 p.m. it is seeing “potential delays and disruptions to departing and arriving flights” and had not posted a newer update as of 6:55 p.m.  All three airports say travelers should check with their airline before heading out.

What it means

• Flying today or Sunday:  The stop has been lifted and Duffy says it is safe to fly, but check your airline’s app before you leave for the airport.  Planes and crews are still out of place, so expect late departures and more cancellations.  FlightAware already counts more than 6,200 U.S. cancellations for Saturday, including 41 at SJC, and Duffy says delays and cancellations will continue as airlines reposition planes and crews.
• Was it a hack?  Officials say they have seen no evidence of a cyberattack or terrorism.  Duffy says a router flooded the FAA’s network during a contractor’s upgrade of old copper lines, and investigators are still working out whether a person or the equipment was at fault.
• Canceled flight:  You can rebook for free or, if you decide not to fly, get a refund under federal rules.  Delta has a change waiver in place.
• Picking someone up:  Planes in the air can still land, but use the airline’s live flight status instead of the original arrival time.
• Thanksgiving trips:  The holiday is Nov. 26.  A one-day stop now should not affect those flights, but check your airline’s app for changes before you leave.
• Live status:  The FAA posts airport-by-airport delays at nasstatus.faa.gov.

Nationwide ground stops are rare.  In January 2023, the FAA halted departures across the country after an outage of its NOTAM system, which sends safety notices to pilots.

Source:  FAA National Airspace System Status, 3:40 p.m. PT Saturday; American Airlines on X, 11:22 a.m. PT Saturday; L3Harris statement on X, 11:08 a.m. PT Saturday; FAA on X, 10:28 a.m. PT Saturday; FAA Administrator Bryan Bedford on X, 9:57 a.m. PT Saturday; Transportation Secretary Sean Duffy on X, 9:42 a.m. PT Saturday; United on X, 8:44 a.m. PT Saturday; Scripps News, Duffy remarks at Saturday briefing, Nov. 14, 2026; White House clips of Saturday briefing (Duffy on investigation; Bedford apology), Nov. 14, 2026; White House clips of Bedford on the network and modernization, Nov. 14, 2026; Los Angeles Times, Duffy remarks on cause, Nov. 13, 2026; The Hill, Duffy funding call, Nov. 13, 2026; Transportation Secretary Sean Duffy briefing stream on X, 7:51 a.m. PT Saturday; Homeland Security briefing summary, Nov. 13, 2026; Transportation Secretary Sean Duffy on X, 5:50 a.m. PT Saturday; FAA on X, 6:13 a.m. PT Saturday; Transportation Secretary Sean Duffy on X, Nov. 13, 2026; Transportation Secretary Sean Duffy on X, 6:25 p.m. PT; Transportation Secretary Sean Duffy timeline on X, 6:15 p.m. PT; Delta on X, 6:21 p.m. PT; Homeland Security clip of Mullin, 6:23 p.m. PT; Transportation Secretary Sean Duffy on X, 5:59 p.m. PT; FAA repost on X, 6:02 p.m. PT; SFO on X, 5:30 p.m. PT; SJC Update No. 2 on X, 5:50 p.m. PT; White House and Homeland Security posts of the 5:30 p.m. briefing; FAA Command Center advisories 111, 116, 117, 119 and 120; FAA on X, 2:02 p.m.; White House video of Secretary Mullin’s remarks; White House briefing by Secretaries Mullin and Duffy; The Hill, Mullin’s remarks; SFO on X, 3 p.m. update; Oakland airport statement, 4 p.m.; San José Mineta International Airport on X; Delta, United and American on X; American travel update, 4:53 p.m.; JetBlue on X, 5:08 p.m.; Hawaii Department of Transportation on X, 5:43 p.m. PT; Hawaii Department of Transportation on X, 5:20 p.m. PT; Hawaii Department of Transportation on X; U.S. Department of Transportation refund rules; FlightAware cancellation and delay counts for Friday and Saturday, 8:13 a.m. PT Saturday; FAA National Airspace System status; FAA on X, 7:05 p.m. PT; United on X, 6:56 p.m. PT; American Airlines on X, 7:30 p.m. PT.