FAA fixing problems at Newark airport while planning overhaul of US air traffic control system

NEWARK, N.J. (WPVI) -- New details were revealed Wednesday on a technical glitch that left air traffic controllers in the dark for up to 90 seconds as commercial flights were inbound to Newark Liberty International Airport.

The FAA revealed that the blackout was likely caused by a data outage, possibly between the old control center on Long Island and the new one in Philadelphia.

While controllers handling Newark are now based in Philadelphia, some of the equipment controlling that airspace is still physically located at New York Tracon in Westbury.

To combat widespread cancellations and delays at Newark, the FAA announced staffing increases and system upgrades -- but didn't give a timeline on when those changes will take place.

The FAA will add three new high-speed bandwidth telecommunications connections between STARS, the ATC digital automation system currently based in Westbury, and Philadelphia. They will also deploy a temporary backup system to Philadelphia, and as U.S. Transportation Secretary Sean Duffy has alluded in the past days, eventually establish a STARS hub in Philadelphia, which could be set up by the mid-summer, to work directly with Newark tower and independently from Westbury.

The agency will replace copper telecommunications connections with updated fiber-optic technology. It was learned earlier this week that Monday's outage was traced to a frayed copper cable.

They will also increase controller staffing at Philadelphia Tracon, although no timetable was given and Duffy admitted that it takes months, if not years.

At the same time, the agency plans to pursue a broader multibillion-dollar plan that will be announced Thursday for long-overdue upgrades to the nation's air traffic control system.

More than 156,000 passengers have had their flights delayed at Newark and thousands more have had flights canceled since last week's computer outage.

It's at least the sixth communication failure to happen there since December.

United Airlines CEO Scott Kirby sent a letter to employees Wednesday insisting that "all the flights in and out of Newark airport are absolutely safe" due to safety requirements already set by the FAA.

But he also called for the number of flights to be restricted to 48 per hour during runway construction. That's far less than the 80 or more routinely scheduled each afternoon and evening.

In the meantime, United Airlines is letting customers change flights for free.

The Chicago-based airline, which has a major hub at Newark, announced that passengers with travel plans to or from Newark through May 17, 2025, are eligible for a "flexibility" waiver that will allow them to reschedule flights without any change fees or fare differences, so long as tickets were purchased on or before May 4.

United said free flight changes only apply to new flights in the same cabin that are leaving and arriving within two days before or after the original travel dates and between the original cities of travel, or Philadelphia or New York.

This is the second waiver announcement from United, following an initial waiver that applied to tickets purchased on or before April 29 for trips scheduled between May 1 and 5.

Newark's struggles also come just as the TSA steps up security. At 12 a.m. Wednesday, the deadline to have a Real ID went into effect.

Another runway is scheduled to open in the middle of next month, which should also help cut down on the problem.

(ABC News and The Associated Press contributed to this report.)