Philadelphia air traffic control outage cancels hundreds of Northeast flights

A failed primary communications line and an accidentally severed backup fiber line at an FAA facility in Philadelphia left controllers without radar or communications for hours. Hundreds of flights were canceled, including more than 600 at Newark Liberty, with operations resuming by Monday evening.

• More than 600 flights canceled at Newark, over 200 at Philadelphia
• Primary line failed; backup fiber was cut by construction crews
• Newark saw no commercial landings from about 9:40 a.m. to 5:20 p.m.
• FAA began testing an AI system for schedule and weather conflicts in D.C.