The FAA cleared its newest AI tool Friday night. Flights had stopped nationwide for four hours earlier that day. A ground stop is the FAA's own order holding planes at the gate, and Friday's covered every airport at once1. Transportation Secretary Sean Duffy named the real cause: old telecom gear.
SMART, the tool officials cleared, had reached every U.S. control center just three days before the stop2. The three-day gap put the new AI system under suspicion right away. Duffy called the two events unrelated1.
What Duffy Says Actually Failed
Duffy named the culprit fast, within hours of the first delay. He pointed at the FAA's radio and data lines, apart from its newest computer program1.
"Our switches, our routers, actually got overloaded with data ... and started to give us inconsistency in the data," Duffy told reporters Friday1. He called the setup "an incredibly old air traffic control system" that still runs on "analog telecom".
The failure hit fast. Radar and communications trouble surfaced by 3:30 p.m. ET, with 3,500 planes already airborne when the stop began at 3:54 p.m.1. Controllers then grounded every other departure behind them.
Duffy drew a hard line between the old wiring and the new software. "There was no possible way SMART would have impacted what happened today," he said1.
Friday's stop ran four hours and 21 minutes, from 3:54 p.m. to 8:15 p.m. ET1. That comes to 4.35 hours, more than four times the length of the FAA's last nationwide stop. A contractor deleted files from a different system in January 2023, and that stop lasted one hour6.
Friday's Ground Stop Ran More Than Four Times as Long as 2023's
Length of the FAA's two most recent nationwide ground stops, in hours
Each column is one ground stop's length in hours: the short column is January 2023's stop, caused by a deleted file, and the tall column is Friday's stop, caused by old telecom gear.
The 2023 figure counts the departure pause after a NOTAM system outage; the 2026 figure counts the FAA's own ground stop advisory window.
Sources: ABC News [1]; Wikipedia [6]. Chart by Ryan Elliott Dennis.
The numbers behind this chart
| Item | Value |
|---|---|
| 2023 outage | 1.00 hrs |
| Nov. 13 stop | 4.35 hrs |
The Vendor and Microsoft Clear Themselves
Air Space Intelligence builds SMART under the $875 million FAA contract2. The Boston company posted its own denial within hours of the stop.
"The current ground stop is not based on or a result of the SMART system, any product of ASI or our integration with FAA and ATC," Air Space Intelligence wrote on X4.
ASI@AirSpaceIntelThe current ground stop is not based on or a result of the SMART system, any product of ASI or our integration with FAA and ATC.
Microsoft issued a similar denial that same night, days after its own Outlook problems earlier in the week3. "We have no indication that the FAA's nationwide ground stop is related to any Microsoft services," Microsoft said.
Mullin, the Homeland Security secretary, backed a more careful version of both accounts. "That's part of something that obviously through CISA at DHS we're taking a look," he told reporters2. "We're working with our counterparts throughout all agencies," he added.
Why a Three-Day-Old Rollout Drew Suspicion
SMART stands for Strategic Management of Airspace, Routes and Trajectories. The tool reads weather, airport congestion and flight paths, then suggests smoother routes to controllers2.
Officials expanded SMART to all 22 of the FAA's en route centers on Nov. 102. The nationwide stop followed three days later. A gap that short invites a question any flier, nervous about a new system, would naturally ask.
SMART only suggests a route. A human controller still decides whether to use it, and keeping two planes apart stays that controller's job alone2. The stop still cost the day more than 5,000 canceled flights nationwide3.
A Question Mullin Leaves Open
Mary Schiavo stays doubtful. She is a CNN aviation analyst and a former Department of Transportation inspector general. Watching the same timeline Duffy did, she read it differently on air Friday5.
"It's just too much of a coincidence that they're trying to start that moving today, and now we have problems with the en route system," Schiavo said5.
She raised a specific worry. A brand-new system might still struggle to talk to decades-old wiring, even if SMART itself stayed clear of any radar screen5.
Mullin left room for her doubt too. Asked about a cyberattack, he said, "It doesn't appear that way," then added, "There's nothing completely certain right now"2. Both officials described the same four hours. Only Duffy called SMART's part in them settled.
Friday's Stop Canceled More Than 5,000 Flights While 3,500 Already Flew
U.S. flights affected by the Nov. 13, 2026 ground stop
The short bar counts planes already in the air the moment the stop began; the long bar counts flights canceled across the whole day of disruption.
The airborne count is a single moment Friday afternoon; the cancellation count covers the full day and is a floor, reported as 'more than 5,000.'
Sources: ABC News [1]; Yahoo News [3]. Chart by Ryan Elliott Dennis.
The numbers behind this chart
| Item | Value |
|---|---|
| Already airborne at 3:54 p.m. | 3,500 flights |
| Canceled across the day | 5,000 flights |
What to do
Two separate questions sit inside this story, and each deserves its own answer. The first: did SMART cause Friday's stop? Duffy, Air Space Intelligence and Microsoft each deny it, and each points to the same old telecom equipment.
The second question stands apart. Should the FAA keep expanding an AI tool while Congress and the GAO review how well the agency tested it? The rollout question survives Friday's telecom finding, whatever caused the stop.
Readers who fly often should watch for the FAA's own technical report. A clean telecom finding answers Schiavo's doubt about coincidence. The testing question still leaves whether the agency checked SMART enough before reaching every center in the country unanswered.
By the numbers
- $875 million: the 12-year contract Air Space Intelligence holds to run SMART2.
- 4 hours, 21 minutes: how long Friday's nationwide ground stop lasted, from 3:54 p.m. to 8:15 p.m. ET1.
- 3,500 planes: already in the air when the FAA ordered every other flight grounded1.
- 3 days: the gap between SMART reaching all 22 control centers and the stop that followed2.
- 1 hour: the length of the FAA's last nationwide ground stop, in January 20236.
- 5,000-plus flights: canceled across the day of Friday's stop, beyond those already in the air3.
What to watch
Watch for the FAA's own technical report on what failed in its telecom network. A report like that would settle Schiavo's coincidence with evidence instead of timing. Named parts and dated logs would do more for a nervous flier than any official's quote. A clear account of the overloaded switches would settle it best.
The Government Accountability Office review that more than 20 lawmakers requested in October stays worth tracking too. Its findings on SMART's testing and training record will land apart from Friday's stop. Either way, that review will tell controllers and travelers something real. It will show how carefully the FAA checked its own work before trusting SMART everywhere.
Sources
- ABC News, "Nationwide ground stop lifted after more than 4 hours as Trump administration blames old, overloaded tech," ABC News, Nov. 13, 2026, https://abcnews.com/US/nationwide-ground-stop-ordered-airports-faa/story?id=138121848
- Click2Houston, "FAA investigating whether new AI technology contributed to nationwide ground stop," Click2Houston, Nov. 13, 2026, https://www.click2houston.com/news/local/2026/11/13/faa-investigating-whether-new-ai-technology-contributed-to-nationwide-ground-stop/
- Yahoo News, "FAA SMART AI system vendor and Microsoft both say ground stop isn't their fault," Yahoo News, Nov. 13, 2026, https://www.yahoo.com/news/us/articles/faa-smart-ai-system-vendor-234927133.html
- Air Space Intelligence, "Post on X," ASI (@AirSpaceIntel), Nov. 13, 2026, https://x.com/AirSpaceIntel/status/2121371183836696583
- Mediaite, "CNN Aviation Analyst Says 'It's Just Too Much of a Coincidence' FAA Rolled Out New AI Traffic Tool Right Before Nationwide Ground Stop," Mediaite, Nov. 13, 2026, https://www.mediaite.com/media/news/cnn-aviation-analyst-says-its-just-too-much-of-a-coincidence-faa-rolled-out-new-ai-traffic-tool-right-before-nationwide-comms-outage/
- Wikipedia contributors, "2023 FAA system outage," Wikipedia, Nov. 13, 2026, https://en.wikipedia.org/wiki/2023_FAA_system_outage
