Thousands of US flights grounded for hours across major US airports, here's why

US travellers faced a tough situation when thousands of flights across United States were stopped on September 21 after a telecommunications outage. As reported by Reuters, the outage forced the Federal Aviation Administration (FAA) to halt arrivals at major East Coast airports. The report further reveals that the service disruption began around 9.45 am when constructions workers accidentally severed a telecom line in New Jersey which led to crippling of communications at a Philadelphia air traffic control facility. Many incoming flights were stopped at all the three major New York-area airports including JFK, LaGuardia, and Newark and Philadelphia, Boston, and two smaller New York-area airports due to the outage. The telecommunications outage lasted for around eight hours and led to widespread cancellation and flight diversions.Thousands of US flights grounded: What went wrongAs per the Reuters report, the trouble began around 9:45 a.m. when workers accidentally cut a telecom line the FAA relies on. The disruption forced the agency to halt incoming flights at all three major New York-area airports, along with Philadelphia, Boston, and two smaller New York-area airports. The problem wasn't fully resolved for roughly eight hours.According to FAA Administrator Bryan Bedford, the outage traced back to a failed circuit at a Philadelphia air traffic control facility that handles traffic for the affected airports. When controllers tried switching to the backup system, they discovered the backup fiber line had also been damaged — a break Bedford said would take roughly 13 hours to fix on its own. A new circuit was being installed in the meantime to restore service faster.Government’s responseInitial blame shifted more than once through the day. Transportation Secretary Sean Duffy first pointed to an Amtrak construction crew, saying it had accidentally cut into a fiber line near New Brunswick, New Jersey. Amtrak pushed back, denying responsibility. New Jersey Transit later said one of its own crews had been digging about 10 feet from utility markings at a nearby work site, and said it was still trying to determine whether Verizon or a contractor was responsible for those markings in the first place. Verizon confirmed it was working to repair the damaged cable and restore connectivity.Airports and flights affectedThe numbers were staggering. Flight-tracking site FlightAware reported around 7,000 flights delayed or canceled nationwide, including 1,400 flights at the three major New York-area airports alone. Newark Liberty International — a major hub for United Airlines — was hit hardest, with more than half of all flights there canceled; United issued a travel waiver to help affected passengers. More than 100 flights were diverted to other airports altogether.Reagan Washington National Airport also briefly paused flights for over an hour due to volume issues, and Philadelphia saw a second ground stop before flights resumed later in the afternoon. Boston's ground stop, triggered by spillover traffic from the other closures, was eventually lifted as well.Services restoredBy around 5:30 p.m., New Jersey Transit said most of the fiber cables had been repaired and were coming back online.Get the latest technology news and updates. Download the TOI App.