Key HighlightsHundreds of flights were cancelled across the US Northeast after an air traffic control communications failure.Newark Airport reported 168 cancellations and 97 delays around 1900 GMT.Philadelphia reported 63 cancellations and 189 delays at the same time.The disruption was linked to a failed primary telecommunications circuit and a damaged backup fibre line.The outage affected Newark, JFK, LaGuardia, Philadelphia and other airports.Flight operations gradually resumed after the damaged communications lines were repaired.What Caused the US Flight Cancellations?The major disruption began on Monday, September 21, after a telecommunications failure affected a Federal Aviation Administration air traffic control facility in Philadelphia.According to US officials, the primary communications circuit failed first. When the system attempted to switch to a backup connection, officials discovered that a fibre-optic line in New Jersey had also been damaged during construction work.The combined failures disrupted communications and radar services used by air traffic controllers, forcing the FAA to restrict or temporarily stop incoming flights at several major airports.Which US Airports Were Affected?The disruption was particularly severe across the New York and Philadelphia region.The FAA temporarily halted incoming flights at Newark Liberty International Airport, John F. Kennedy International Airport, LaGuardia Airport and Philadelphia International Airport. Boston and smaller airports in the New York area were also affected by the wider disruption.Newark experienced one of the most significant impacts, with commercial arrivals halted for several hours. More than 600 flights at Newark were eventually reported as cancelled or affected by the disruption.How Many Flights Were Cancelled?FlightAware data showed that around 1900 GMT, Newark Airport had recorded 168 cancelled flights and 97 delays.Philadelphia International Airport had 63 cancellations and 189 delays at the same time.Across the wider US network, thousands of flights were delayed or cancelled as the disruption created a backlog that extended beyond the airports directly affected by the communications outage.Reuters reported that around 7,000 flights across the US were delayed or cancelled, including approximately 1,400 at the three major New York-area airports. More than 100 flights were also diverted to other airports.When Did Flight Operations Resume?The FAA and transportation authorities began restoring operations later on Monday after repairs were carried out on the affected telecommunications infrastructure.Transportation Secretary Sean Duffy said that operations were resuming across the Northeast but warned that it would take time for airlines and airports to clear the existing backlog.Newark and LaGuardia gradually resumed arriving flights, while operations at Philadelphia also restarted. However, passengers continued to face delays and cancellations as airlines worked through the disruption.What Did the FAA Say About the Line Outage?FAA Administrator Bryan Bedford said the disruption involved failures affecting both the primary and backup communications systems.The backup fibre line was described as having a major break, with officials initially estimating that repairs could take several hours. A replacement circuit was also being installed to restore the primary connection.The incident has renewed attention on the reliability of the US air traffic control communications network and the need to modernise ageing infrastructure.What Should Passengers Do?Passengers travelling through affected airports have been advised to check their flight status directly with their airline before travelling to the airport.Although the telecommunications problem was repaired and normal operations began returning, authorities warned that delays could continue because of the large backlog created during the outage. Some airlines also offered affected passengers options to change flights without additional fees.Timeline of the US Flight DisruptionSeptember 21, around 9:45 am: A telecommunications problem began affecting the FAA facility in Philadelphia.Later in the morning: A backup fibre-optic line was found to have been damaged in New Jersey.During the disruption: Incoming flights were restricted at major airports including Newark, JFK, LaGuardia and Philadelphia.Around 1900 GMT: Newark had 168 cancellations and 97 delays; Philadelphia had 63 cancellations and 189 delays.Monday evening: Repairs allowed operations to gradually resume across the Northeast.September 22: Airlines continued working to clear remaining delays and cancellations.The US telecommunications line outage caused widespread disruption across the country's aviation network, with the effects continuing even after air traffic control operations resumed. Passengers have been advised to check individual flight status updates before travelling.
