The Federal Aviation Administration issued a rare nationwide ground stop Friday afternoon, after outdated air traffic communications equipment became overloaded with data and began to fail, officials said.
The outage stranded thousands of passengers and caused widespread delays from which airlines and airports are still struggling to recover. It also highlighted persistent vulnerabilities in the aging U.S. air traffic infrastructure and a funding fight, as administration officials demanded lawmakers approve tens of billions of dollars more to accelerate systemwide upgrades.
Here’s what to know.
What caused the problem?
Sean Duffy, the transportation secretary, told reporters at the White House Friday night that the radar and other air traffic communications started to falter at 3:36 p.m. when old routers became overloaded with data. While the failures were not universal, they were pervasive enough to prompt officials to issue the unusual nationwide moratorium on takeoffs, Mr. Duffy said.
Appearing alongside him at the White House, Markwayne Mullin, the homeland security secretary, stressed that there was no evidence that nefarious activity had triggered the technology failures.
“We’ve seen zero evidence that this was a cyberattack,” Mr. Mullin said, suggesting that new equipment and new technology the Mr. Duffy’s department had added to the old infrastructure was what had overwhelmed it.
Mr. Duffy insisted that the failure was caused by the antiquated, legacy communications equipment, not recent upgrades to the system.
“What we have is an incredibly old air traffic control system,” Mr. Duffy said, predicting that until significant upgrades are made, “it’s going to continue to fail.”
How long will it take to get things back to normal?
Mr. Duffy warned that it would take “some time” for air travel nationwide to recover from the ground stop, predicting flight schedules would be fully back to normal by the time the Thanksgiving travel season begins.
“I believe that it’s going to take us some time to get back to capacity,” he said, adding: “We’re going to have some makeup to do.”
Mr. Duffy said that the F.A.A. would prioritize larger commercial flights ahead of private and charter flights, to get previously grounded flights off the ground.
What does the administration say needs to be done?
Mr. Duffy has long been pushing for a sweeping overhaul of the U.S. air traffic infrastructure, routinely complaining that controllers have been hampered by the country’s failure to upgrade outdated equipment.
“We have old, old switches, old routers — we use 1980s little copper lines,” he said to reporters Friday. Only last week, the F.A.A. announced that it had begun to phase out the use of floppy disks.
Last year, Congress approved $12.5 billion to fund upgrades to the country’s aging air traffic facilities and networks, some of which has been directed toward communications system upgrades. Mr. Duffy noted Friday that air traffic facilities that had been upgraded to digital systems did not experience the same overloading issues that prompted the F.A.A. to issue the ground stop order.
But he stressed that having an air traffic control system dependent on a “patchwork” of upgrades and fixes was untenable, calling on Congress to spend tens of billions more to allow for more upgrades.
Why did Duffy blame Congress?
For months, Mr. Duffy has been calling on the Republican-controlled Congress to give his department another $30 billion to accelerate efforts to upgrade air traffic control systems. On Friday night, he upped the ante, telling reporters he wanted $50 billion — and that he wanted it before the end of the year.
“This is an emergency, I want Congress to give us emergency funding,” he said, adding: “How many more times does this have to happen for Congress to give the money to fix it?”
But it is unclear whether Republicans will prioritize such a sum before the end of the year, after which control of Congress shifts to the Democrats, who are expected to scrutinize how the F.A.A. has utilized air traffic funding they have received so far. Republican lawmakers have filed bills in the House and Senate to authorize $30 billion in air traffic upgrades, but neither piece of legislation has cosponsors.
Later on Friday, Representative Hakeem Jeffries of New York, the House’s top-ranking Democrat, appeared to reject Mr. Duffy’s accusing tone and shifted the blame back to the Trump administration.
“Today’s unprecedented breakdown is the latest in a series of unacceptable air travel incidents under the Trump administration’s failed leadership,” he said in a statement, adding that “American travelers deserve timely answers from the Trump administration about how and why this happened and assurances that steps are being taken to ensure that our air travel system remains safe and functional.”
