Philadelphia air traffic control outage resolved, Northeast airports resume operations

Damaged communications lines at the Federal Aviation Administration's Philadelphia air traffic control facility were repaired on Monday, allowing airports in the Northeast to resume operations after several hours of disruptions, Transportation Secretary Sean Duffy said on X. The FAA had issued two ground stops at Philadelphia International Airport, which halted hundreds of flights in the region.

The primary communications line at the facility failed early Monday, and a backup fiber-optic line was inadvertently severed during nearby construction, leaving controllers without radar or communications. The outage forced a near-standstill of commercial traffic at Newark Liberty International Airport from about 9:40 a.m. to after 5:20 p.m. local time, and more than 200 flights at Philadelphia were canceled. Nationwide, more than 1,000 flights were canceled and over 6,000 delayed, with Newark and Philadelphia experiencing the greatest impact.

"It will take some time to clear all existing delays, so please check with your airline for the latest information," Duffy wrote.

The FAA advised travelers to verify flight status before heading to the airport, and some airlines offered free rebooking. The agency identified an Amtrak construction crew and a New Jersey Transit crew as possible sources of the fiber-optic cut. FAA Administrator Bryan Bedford said technicians focused on installing a new circuit on the primary line while repairing the backup line, and Verizon technicians also worked on restoration.

The primary circuit is slated for replacement as part of a broader modernization of the nation's air traffic control system. Separately, the FAA began testing an AI-based computer system to predict scheduling and weather conflicts, though the trial is limited to the Washington, D.C., area and is not linked to the outage.