Freya Scott-Turner
Live reporter

Image source, Bloomberg via Getty Images

It's been a manic Monday for multiple airports across the northeastern US, after an equipment issue delayed hundreds of flights. Major airports in New York, Philadelphia, Boston and New Jersey were among those affected.

The problem? A malfunction of a system which guides planes during take-off and landing, called the Terminal Radar Approach Control System.

Aviation administrator Bryan Bedford said that a circuit had failed, and the system went down because a backup cable had been damaged by a construction crew in New Jersey.

The travel chaos has come on the eve of the United Nationals General Assembly, which will see more than 130 officials from around the world jet into New York.

There are signs of improvement, with flights starting to resume at New York's LaGuardia Airport and Philadelphia Airport, but delays remain.

Duffy said the incident "underscores the need for additional funding" to modernise "ageing infrastructure".

Meanwhile, telecommunications company Verizon said it was "actively working" to repair the cable restore connectivity, but Bedford warned of a lengthy repair process that could take as long as 13 hours.

• We're ending our live coverage now, but you can get further updates on the ongoing US flight disruption in our news story here.

Douglas Tewnion is heading to New York from Edinburgh, but saw his flight diverted to Boston on approach.

He tells the BBC that, two hours after his flight was due into New York, they are still "sitting on the same plane, on the tarmac at Boston with no information".

Though "everyone is in good spirits", Tewnion says "it's just a pain" to see two more hours waiting added onto a lengthy flight.

He adds that he appreciates "there will be a backlog", but more information would help him make onward plans.

As we've been reporting, the air traffic control issues started today when a construction crew accidentally severed a fibre cable needed for communication.

US Transportation Secretary Sean Duffy initially said a crew working for railway company Amtrak was behind the incident.

The BBC's US partner CBS News obtained a statement from NJ Transit, a different train operator based in the state of New Jersey, which says its crews accidentally damaged the cable.

"At approximately 9:45 a.m. today, a construction crew working on the Delco Lead project between New Brunswick and North Brunswick accidentally severed a fiber-optic cable while working at the site," the statement says.

NJ Transit adds that its crews were several feet away from marked indicators that should have shown the location of the cables. It says it's working to determine who placed those markings, as well as the other circumstances around the incident.

Image source, Getty Images

In the event of delays or cancellations, the US Department of Transportation (DOT) sets out on its website when consumers are eligible.

For cancelled flights:

• You are entitled to a refund "if the airline cancelled a flight, regardless of the reason"
• It adds that if the airline offers travel credits, vouchers, or other forms of compensation in lieu of a refund, it "must also let you know that you are entitled to a refund"

For delayed flights:

• You can get a refund if the airline "significantly delays" or "significantly changes" a flight
• "Significant" delays or changes include arriving at a domestic destination more than three hours late, or at an international destination more than six hours late
• But crucially, the DOT says you cannot claim a refund if you still travel on the delayed flight or on an alternative one offered by the airline Although you may be able to claim compensation for amenities

US telecommunications company Verizon says it is "actively working" to repair the backup cable needed for air traffic control. We heard earlier that damage to the cable is the cause of the ongoing flight disruption that's hit multiple airports across the US.

In a statement shared with US media, Verizon says it "bears no responsibility" for the incident.

“We have a fiber cable running adjacent to an Amtrak rail line in New Jersey," it says. "Construction contractors working in the area dug up and cut our cable."

"Verizon's facilities were fully functional up to that point," it notes, adding that it is "actively working to repair the damaged cable and restore connectivity as quickly as possible".

US Transportation Secretary Sean Duffy has said that a construction crew working for national rail operator Amtrak cut the cable accidentally.

Newark Liberty International Airport in New Jersey has been the most heavily impacted by today's air traffic control disruptions, according to flight-tracking website FlightAware.

According to the website, there are 267 departing flights that were delayed today.

There were also a further 257 flights destined for Newark that were delayed.

That's nearly double the delays that they saw yesterday before the technical problems began.

Newark Airport is located in New Jersey, but it's one of the three main international airports that services neighbouring New York City.

Image source, Getty Images

US Transportation Secretary Sean Duffy is calling for more money to be allocated to improving American aviation systems as delays and stoppages continue.

"This incident underscores the need for additional funding to modernize aging infrastructure and prevent disruptions like this in the future," he wrote on social media.

Improving air traffic control systems has been an ongoing discussion in the US for years.

Last year, Congress approved $12.5 billion (£9 billion) to ⁠upgrade the system and boost the recruitment of controllers. It's move that came after decades of complaints over airport ​congestion and flight delays and a series of technology ​issues ⁠in recent years.

Some air traffic control equipment dates back to the 1960s, the White House said last year.

The Federal Aviation Administration (FAA) has an airspace monitor which shows how various airports are being affected by ground stops and delays.

It lists three airports as currently experiencing ground delays due to "equipment outage" - this was the reason for the disruption given by John F Kennedy airport earlier. These are:

• Departures to John F Kennedy International are delayed by an average of 72 minutes
• As LaGuardia airport, delays are averaging 44 minutes
• Ground delays at Philadelphia international airport are averaging212 minutes

The site also shows delays averaging 105 minutes for departures to Boston Logan international airport - which had also reported disruption earlier - but it confirms that this is due to weather conditions rather than equipment.

We've just heard from US Transportation Secretary Sean Duffy, who says flights are resuming at New York City's LaGuardia International Airport and Philadelphia International Airport.

In his latest update, Duffy adds that flights into Newark Liberty International Airport, New York City's John F Kennedy International Airport and Teterboro Airport in New Jersey are "paused".

Ione Wells
North America Correspondent

Image source, Bloomberg via Getty Images

As we mentioned earlier, the outage comes a day before world leaders are due to gather in New York for the annual high-level United Nations General Assembly.

The New York airport ground stops are only due to impact planes that hadn’t already taken off. UK Prime Minister Andy Burnham's plane was already in the air, so is currently due to land as normal.

Delegations who were not already en route at the time of the outage could be delayed though, or people could be diverted while the ground stops remain in place.

Image source, Getty Images

As we've been reporting, US officials have said that the flight disruption was caused by damage to a backup cable needed for air traffic control.

In an update, US Transportation Secretary Sean Duffy says that it was a construction crew from Amtrak - the national operator of intercity railroad services - which cut the backup cable.

"An Amtrak construction crew accidentally cut into a fiber line in New Jersey," Duffy says on X.

This "caused a telecom outage" which forced the Federal Aviation Administration to ground flights, he adds.

Duffy notes that flights are now resuming at LaGuardia Airport in New York City and Philadelphia Airport.

This incident "underscores the need for additional funding to modernize aging infrastructure", he writes.

These airspace issues in the US come ahead of a busy time in New York City, where world leaders are due to gather on Tuesday for the annual United Nations General Assembly.

Over 130 officials from around the world are expected to attend.

Ground stops and delays continue to affect the three international airports that service New York City, though it's unclear how that might impact things tomorrow.

Airports across the northeastern US continue to be impacted by an air traffic control malfunction that's impacted dozens of flights.

A tracking system maintained by the US Federal Aviation Administration shows most of the delays or ground stops have yet to be resolved.

Here is a list of the airports currently being impacted:

• Boston's Logan International Airport - ground delay
• New Jersey's Newark Liberty International Airport - ground stop
• New York City's John F Kennedy International Airport - ground delay
• New York City's LaGuardia International Airport - ground delay
• Pennsylvania's Philadelphia International Airport - ground delay
• New Jersey's Teterboro Airport - ground stop

Rachel Flynn
Live reporter

We know:

• Ground stops were issued on Monday afternoon for major US airports in New York, Philadelphia, New Jersey and Boston, disrupting dozens of flights
• US officials say the issue is related to frequencies at a Philadelphia-based air traffic control system which guides planes during take-off and landing
• New York City's John F Kennedy International Airport and Boston's Logan International Airport are urging travellers to call their airlines before arriving for their flights
• US aviation officials say a "circuit failed" which then led to the discovery of a backup fibre circuit which had been damaged by construction crews in New Jersey
• Repairing the backup cable would take around 13 hours, they said
• So far, around 90 flights have been diverted to other regions, officials estimate

We don't know:

• When the ground stops will lift
• How many flights, at how many airports, will ultimately be affected

US Transportation Secretary Sean Duffy and aviation administrator Bryan Bedford just briefly spoke to reporters after an unrelated event.

Bedford confirmed that the malfunction was related to the Terminal Radar Approach Control System, which guides planes during takeoff and landing. He added that a "circuit failed", which then led to the discovery of a backup fibre circuit which had been damaged by construction crews in New Jersey.

He said that to repair the backup cable would take around 13 hours.

"It's massive, I'm told," Bedford said.

He added that the cut fibre line is around 600ft (183m) long, and that it was inadvertently damaged during "construction".

"Somebody dug it up," Bedford says.

Fixing the issue requires turning everything off - "sanitising the airspace" - and making sure that all flights are safe. So far, around 90 flights have been diverted to other regions, he estimated, saying he didn't know about the number of total cancellations.

Duffy added that these problems "are not new to us" and called on Congress to provide more cash to update the system.

This flight disruption comes on the same day that a new report from a government watchdog, external points to vulnerabilities in US aircraft communications.

The Government Accountability Office (GAO) says that Federal Aviation Authority's (FAA) air traffic and communications systems are "vulnerable to cyber threats", including spectrum interference, spoofing and jamming which the report said could disrupt communications between aircrafts and ground control.

It adds that the FAA "hasn't sufficiently addressed" the threats, laying out several issues including a lack of real-time monitoring and detection software and a failure to complete risk assessments.

The FAA has not stated that a cyber attack is the cause of the ongoing disruption. US media are currently citing an issue with "frequencies" at Philadelphia air traffic control.

Major US airports are now cautioning travellers about delays.

New York City's John F Kennedy International Airport posts on X: "Due to an FAA equipment outage, arrivals and departures are currently experiencing delays at #JFK. Please contact your airline for flight status."

Boston Logan International Airport posts on social media that the issue is due to air traffic control “equipment issues across the northeast”.

“Flights are being impacted across the country, including here at Boston Logan," the airport says, urging travellers to check on delays before arriving at the airport.

Scores of flights have been disrupted at airports in north-eastern US due to telecommunication issues affecting air traffic control, according to the US Federal Aviation Administration (FAA).

Ground stops were issued on Monday afternoon for major airports in New York, Philadelphia, New Jersey and Boston.

The issue is related to frequencies at the Philadelphia air traffic control, which handles traffic for airports in the region, US media reports. It's unclear when the ground stops will lift, and the BBC has approached the FAA for a statement on the issue.

An FAA spokesperson told the BBC's US partner CBS that the problem affected the Terminal Radar Approach Control system, which is used to guide planes during take-off and landing.