An FAA air traffic control tower. Photo: Tony Webster / Wikimedia Commons (CC BY-SA 2.0)
US air travel was still struggling to recover on Sunday after a nationwide shutdown that grounded flights across the country, after officials blamed a single faulty router installed by a government contractor for the worst disruption to American aviation in a quarter of a century.
The Federal Aviation Administration ordered a nationwide ground stop on Friday that halted nearly all departing flights for almost five hours. It was the longest nationwide halt to US air travel since the September 11, 2001 attacks and one of the worst travel days in American history.
By Saturday evening, the damage was still mounting. Airlines had canceled more than 6,150 US flights and delayed more than 7,300 on Saturday alone, according to flight tracking site FlightAware. That followed about 9,200 cancellations and 7,500 delays on Friday. More than 530 flights scheduled for Sunday had already been canceled by Saturday night.
A Router That Flooded the System
Transportation Secretary Sean Duffy said on Saturday that the problem was traced to FAA contractor L3Harris, which was installing at least one new router at a remote facility as part of routine maintenance to switch air traffic control telecommunications lines from old copper wire to fiber-optic cable.
Something in that work went badly wrong. The router began flooding the network with more than 1,000 connection attempts every four to five seconds, overwhelming communications at 17 of the FAA's 22 en route centers — the facilities that control aircraft during the cruise portion of a flight.
"We're working to determine whether we had incompetence, meaning was it user error or installer error from L3Harris, or did they install a faulty router? We haven't determined what the fault was," Duffy told reporters at a news conference on Saturday.
Officials said there may have been problems with routers installed in both Arkansas and Texas. L3Harris said it took the issue seriously and was supporting the FAA's investigation. Its shares fell about 4 percent in after-hours trading on Friday.
The FAA said it was doing additional testing with L3Harris to see whether there are any further risks in the system.
White House Scrambled as Fears of a Cyberattack Grew
The scale of the failure initially raised fears of something far worse. The White House convened an emergency meeting in the Situation Room on Friday, and federal agencies scrambled to determine whether the outage was a cyberattack.
It was not. FAA Administrator Bryan Bedford said the system remained stable and apologized for the disruption, adding that he expected airline operations to largely return to normal by late Sunday.
Bedford said the FAA ordered the ground stop in case a center lost all communications. "No facilities went dark. Nothing was fully lost," he said.
Even so, the human cost was enormous. Tens of thousands of passengers were stranded in airports across the country, airlines struggled to get flight crews and aircraft back into position, and some college football teams were stranded on Friday before games scheduled for Saturday. Delta Air Lines, United Airlines and American Airlines each canceled about 25 percent of their flights on Saturday, while JetBlue canceled nearly 45 percent. Airlines issued travel waivers allowing passengers to rebook without cost.
An Aging System Under the Spotlight
Friday's shutdown is the latest and most dramatic sign of strain on a US air traffic control system beset by aging technology, failing equipment and a shortage of several thousand controllers. The FAA's telecom systems have failed several times in recent years after fiber-optic cable cuts, accidental file deletions and a melted component that filled a facility with a strong chemical smell.
"This was an FAA system that didn't meet the moment," Duffy said on Saturday.
Duffy called on Friday for $50 billion in funding to upgrade air traffic control systems, up from his earlier request of $30 billion, after Congress approved $12.5 billion last year. House Speaker Mike Johnson said on Saturday that he supports approving more funding for air traffic this year.
Democrats who are set to chair the House Transportation and Infrastructure Committee and its aviation subcommittee next year said their panels would "hold the administration accountable for what happened to make sure this chaos does not happen again." They noted that since receiving $12.5 billion last year, the Transportation Department has awarded contracts worth $4.3 billion but spent only $1 billion.
For now, travelers face at least one more day of disruption before the system returns to normal — a reminder of how fragile the infrastructure guiding America's skies has become.
Sources: Reuters, Associated Press. Flight data: FlightAware.