US Flight Disruptions Persist After Nationwide Air System Shutdown

Passengers across the United States faced another day of turmoil in the skies, with the head of the Federal Aviation Administration warning that normal flight schedules were unlikely to resume until later today as the system works its way back from a rare, nationwide shutdown blamed on routine maintenance that went wrong.

By 9:35pm ET (2.35am Irish time), airlines had cancelled more than 6,400 US flights and delayed more than 8,000, according to FlightAware, an aviation website.

The latest wave of disruptions followed Friday’s chaos, when about 9,200 flights were cancelled and 7,500 delayed after the FAA ordered a nationwide ground stop because of disruptions to air traffic communications.

FlightAware said 875 flights scheduled for today were already cancelled.

FAA Administrator Bryan Bedford said he expects airline operations to largely return to normal later.

He apologised for the disruption and said the system remains stable.

The FAA’s nationwide ground stop on Friday halted nearly all departing flights for almost five hours. It marked the longest nationwide halt to air travel since the attacks of 11 September 2001, and ranked as one of the single worst US travel days ever.

The abrupt breakdown was serious enough that the White House convened an emergency meeting in the Situation Room, while federal agencies rushed to assess whether a cyberattack might be to blame.

A woman waits to hear about the resumption of flights at Miami International Airport

Officials later traced the problem to FAA contractor L3Harris, after the installation of at least one new router at a remote facility, Transportation Secretary Sean Duffy said.

“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,” Mr Duffy said at a press conference.

The Professional Aviation Safety Specialists, a union representing FAA safety employees, said the issue was isolated to two routers that were updated Friday.

An official told Reuters it was believed the routers were in Arkansas and Texas.

An FAA official said the agency conducted a safety assessment before the work.

L3Harris said it took the issue seriously and is supporting the FAA in its investigation. Its shares last traded down about 4% after hours on Friday.

Overloaded communications centres

Mr Duffy said the trouble surfaced Friday afternoon as air traffic control centres began experiencing instability in radar and communications systems. Officials said the router problem then spilled over, sending data that overloaded other communications centres.

“We had over 1,000 connection attempts every four to five seconds, and what that did was (it) gave us issues with our communication with airplanes, and it also caused some disruption with our radar,” Mr Duffy added.

Communications were affected at 17 of the FAA’s 22 en route centres, which guide aircraft during the cruise portion of a flight.

Mr Bedford said the FAA ordered the ground stop out of caution, in case any centre lost all communications.

“No facilities went dark. Nothing was fully lost,” Mr Bedford added.

Passengers wait at the check-in desks of Los Angeles International Airport

The FAA said it was conducting additional testing with L3Harris to determine whether any other risks remain.

Delta Air Lines, United Airlines and American Airlines each cancelled about 25% of their flights yesterday, while JetBlue cancelled nearly 45%.

Airlines have issued travel waivers allowing passengers to rebook flights for later dates without cost.

Even after the FAA lifted the ground stop Friday evening, the ripple effects continued, leaving tens of thousands of travellers stranded in airports.

Airlines worked to reposition flight crews and other personnel so operations could resume.

Funds sought to fix system strain

The episode is the latest — and most dramatic — example of strain within a US air traffic control system grappling with ageing technology, equipment and communications problems, along with a shortage of several thousand controllers.

Mr Duffy renewed his push for $50 billion in funding to upgrade air traffic control systems, raising his earlier request of $30 billion after Congress approved $12.5 billion last year.

Planes sit at their gates at Ronald Reagan Washington National Airport in Washington DC

House Speaker Mike Johnson told Fox News he supports approving additional funding for air traffic this year.

Republicans led by Mr Johnson will control Congress until next year, when Democrats will take over after gaining ground in the 3 November midterm elections.

US Representatives Rick Larsen and Andre Carson, Democrats slated next year to chair the House Transportation and Infrastructure Committee and aviation subcommittee, respectively, said in a joint statement that their panels will “hold the administration accountable for what happened to make sure this chaos does not happen again.”