The problems keep coming for Newark Liberty International Airport. On Monday, it was a staffing shortage at an air traffic control facility that serves the airport.
Most flights destined for Newark were being delayed at their origin airports by more than an hour and 40 minutes midday on Monday because too few air traffic controllers were available. The Federal Aviation Administration was also expecting to be short on controllers for Newark for about four hours on Monday night, according to an advisory posted online.
The F.A.A. said in a separate advisory that it was delaying the incoming flights up to nearly seven hours from all airports in the contiguous United States and some in Canada. Such delays are not uncommon, but can have cascading effects on flights around the world.
Monday’s delay was the latest in a string of setbacks for Newark, one of the nation’s busiest airports and a large hub for United Airlines. On Friday, the air traffic control facility in Philadelphia that guides planes at the airport had a brief radar outage. A similar outage late last month had left controllers unable to communicate with pilots for about 30 seconds.
That outage, on the afternoon of Monday, April 28, had followed months of glitches and other problems that have rattled the controllers who manage the Newark airspace. The F.A.A. moved that work from a facility in Long Island, New York, to the one in Philadelphia last summer in the hopes that relocating to a more affordable area would help in hiring more controllers.
As of March 2024, only 59 percent of available controller roles were filled at the air traffic control facility that handled flights at Newark, LaGuardia Airport, Kennedy International Airport and other New York airports before the Newark responsibility was moved to Philadelphia.
The recent outages were caused by software and hardware problems, which, when combined with staffing limitations and runway construction, have contributed to lengthy delays at Newark in recent weeks. In a news conference on Monday, the transportation secretary, Sean Duffy, said that the earlier outages had been caused by an antiquated backup telecommunications line that had been overwhelmed when a primary line failed.
“We are trying to slow speeds down to 1990 speeds for 1980 equipment,” he said.
To reduce delays, Mr. Duffy said that he also planned to reduce the number of flights at the airport. The department is expected to meet with airline executives on Wednesday to discuss how best to do that. United, which operates about two-thirds of flights at Newark, has already cut back on some flying there.
Mr. Duffy said that the F.A.A. had installed software updates on Friday to prevent future outages, and plans infrastructure upgrades, including new fiber-optic cables connecting the airport and the facility in Philadelphia.
In the news conference, Mr. Duffy repeatedly sought to blame the Biden administration, saying it had “bungled” the move from New York last summer. He said he had also asked the department’s inspector general to investigate the shift to Philadelphia.
A spokesman for Mr. Duffy’s predecessor, Pete Buttigieg, said in a statement that “Secretary Duffy has a tough job. But he needs to spend more time doing what the American people are paying him to do — fix problems — and less time blaming others.”
When asked if controllers from other air traffic hubs around the country could be moved to Philadelphia, Mr. Duffy said on Monday that it could take one year, at best, to train controllers on managing the new airspace. The average time to certify a controller for the complicated airspace is two and a half years.
At the news conference, Chris Rocheleau, the acting administrator of the F.A.A., also emphasized that flying at the airport is safe. Starting on Monday, he said, the agency had convened a task force to address the problems, including representatives from the F.A.A. and technology and telecommunications contractors.
Tim Balk contributed reporting.
