Investigators from the NTSB arrived at Newark Liberty International Airport on Monday after a near catastrophe over the weekend.
The brief outage happened at 3:55 a.m.
The facility where controllers work the airspace around Newark airport is located in Philadelphia and was already short air traffic controllers.
Several issues have led to delays and cancellations for about a week, and those disruptions were happening again Monday morning.
Theresa Claiborne had her final flight with United Airlines on Thursday.
A United flight from London to Newark diverted to Bangor on Friday after the crew reported a passenger disturbance.
