The communications outage that caused flight delays at a key air traffic control facility in Philadelphia has been resolved. Transportation Secretary Sean Duffy confirmed that damaged lines have been fully restored, allowing airports across the Northeast to resume flight operations after hours of disruptions.

The Federal Aviation Administration (FAA) had issued two ground stops at Philadelphia International Airport on Monday, September 21. Taking to X on Monday evening, the transportation secretary shared a statement confirming that telecom lines had been repaired and "all airport operations in the Northeast are resuming."

The equipment outage led to over 1,000 flight cancellations and more than 6,000 delays on Monday, September 21, with Newark and Philadelphia being the worst affected. The key telecom line at the FAA facility in Philadelphia went down earlier on Monday after construction workers accidentally damaged the backup fiber optic cable, leaving air traffic controllers without radar or communications for hours.

According to Flightradar24, the outage brought commercial air traffic to a near-standstill at Newark Liberty International Airport for most of the day. Over 200 flights into and out of Philadelphia International Airport were also canceled, while disruptions hit LaGuardia and Kennedy airports in New York. Flight operations at these airports were successfully restored by Monday evening.