At least 80 flights were cancelled and around 40 were delayed at Newark Liberty International Airport on Sunday morning amid a back-to-back aviation crisis in Newark. The FAA said in a statement that a telecommunications issue at the Philadelphia TRACON Area C facility, which guides aircraft in and out of Newark, caused the agency to issue a ground stop for 45 minutes. Operations have returned to normal now but this was the third time that air traffic got affected in Newark. On Friday morning, radar screens at the airport went black for about 90 seconds, according to the FAA. During the outage, which unfolded about 3:55 a.m., air traffic controllers could be heard telling a FedEx plane that their screens went dark and then asking the aircraft to tell their company to put pressure on to get the problem fixed.

What’s happening in US airspace?

The outages come when the US airspace witnessed some of the most tragic crashes this year. Transport secretary Sean Duffy on Saturdat said he is concerned about the whole airspace of the United States as FAA is using old equipment. “I’m concerned about the whole airspace,” Duffy said during an interview with NBC News’ Meet the Press. “The equipment that we use—much of it we can’t buy parts for new. We have to go on eBay and buy parts if one part goes down.”“You’re dealing with really old equipment. We’re dealing with copper wires, not high-speed fiber,” he said.Duffy said Sunday “it is” safe to fly out of Newark airport, adding that flights will be scaled back at the airport in the interim while the issue is fixed.He didn’t say exactly how long delays and cancellations will last, but said, “In the next several weeks, we’re going to have this reduced capacity at Newark. I’m convening a meeting of all the airlines that serve Newark, get them to agree on how they’re going to reduce the capacity. So you book, you fly.”“We are building a new line that goes directly from Newark to the Philly Tracon, which controls the New York airspace,” Duffy said, adding he believes that will be complete by the end of the summer.