The Federal Aviation Administration has fast-tracked new telecommunications lines at three of the nation’s largest airports, and will transfer operations to secure fiber optic cable from aging copper wires in the next two weeks, Secretary Duffy said Monday.

“The FAA today is assembling a team of experts to fully fast-track the fixes that we’ve identified need to be done to make sure this works,” the transportation chief said during a Monday press conference that followed a series of delays and cancellations at Newark-Liberty International Airport that set off a cascade of problems across the nation. The technical failures plaguing the transportation hubs have shaken confidence among air travelers worried about communication outages at air traffic control towers.

“The FAA has replaced copper lines with fiber lines at Newark, [John F. Kennedy International Airport], and La Guardia. That work is done,” Mr. Duffy said. “It was done over the last couple weeks, however, it’s going to take another week or two to test those two lines before we flip the switch and make them live.”

Mr. Duffy also announced that radar systems will be updated to better handle the speed of data required by air traffic controllers. He added that a temporary backup system will be sent to the Philadelphia radar control center, which handles air traffic for Newark-Liberty, after three outages in as many weeks.

“Our hope is to have high-speed fiber connections and then new technology in these towers, and centers so we can maximize the use of American airspace,” he said.

An equipment outage Sunday led to the cancellation of 80 flights at Newark, with another 60 delays. The backup followed a Friday radar malfunction that brought the airport to a standstill. 

The issues are cascading to other major travel hubs across the country, compounding an already stressed air traffic system that is also suffering from a shortage of air traffic controllers.

Hartsfield-Jackson Atlanta International Airport issued a 45-minute ground stop Monday due to “runway equipment issues.” Austin-Bergstrom International Airport in Texas reported delays of up to 91 minutes on Sunday due to “chronic understaffing” at the air traffic control tower.

“ABIA is supposed to have 60 controllers. But as of January, they had only 32,” a KUT transportation correspondent, Nathan Bernier, said in a post on X.

Responding to the outages on Friday, Senate Minority Leader posted on X criticizing the administration. “Trump needs to get it together now” on airline safety, he wrote”and stop risking safety so DOGE can play government.” Mr. Schumer added that Newark should be first in line for critically needed fixes.

Mr. Duffy had warned Sunday that take-offs and landings at Newark would be slowed while transportation officials work on fixes to the aging air traffic facilities, which he said date as far back as 50 years. Responding to criticism that the administration was not moving fast enough, Mr. Duffy on Monday placed the blame for the faulty systems squarely on the Biden administration.

“This did not have to be our story. Over the last four years, the last administration, they knew this was a problem,” he said, adding, “and by the way, during COVID, when people weren’t flying, that was a perfect time to fix these problems, but again, they got $1.2 trillion for infrastructure and virtually none of it went to fix the biggest American infrastructure problem that we have, which is our air traffic control system.”

He defended President Trump, saying he was aware of cracks in the system near the end of his first term and planned upgrades before Mr. Biden took office.

“But the last administration, they did nothing about it,” Mr Duffy said. “As things get old, you get to the point where you’re starting to hear some rattles in your car, that’s probably the sign you need to bring it to the shop.”

The slowdowns at America’s airports are not just technological. They have been compounded by the dwindling number of available air traffic controllers. Only 2 percent of the nation’s airports are fully staffed. The FAA needs 3,000 more air traffic controllers across the country to fill all the openings. 

Recruitment for new controllers has proven to be difficult. The job is often stressful and unpredictable and has a specific set of requirements, including being under the age of 31 in order to work up to 25 years before a mandatory retirement at 56, completing rigorous training, and getting up to three years of on-the-job experience, according to the aviation administration.

The shortage has prompted creation of a federal collegiate training program in which the aviation administration has partnered with five schools to provide enhanced training for recruits right out of college.

The participating schools, which include the University of Oklahoma and the Vaughn College of Aeronautics and Technology in New York, offer an enhanced training program with air traffic control training that is equivalent to programs at the FAA Academy.

To stem the flow of departing controllers, Mr. Duffy is increasing the retirement age for air traffic controllers to 61 from 56. Congress has given him the authority to do so.

However, even with the additional workforce, improvements may not come overnight.

“We don’t have the ability to just snap our fingers and move controllers around. It takes time to train up specifically on the airspace in which they control,” he said. “You gotta see over the horizon on how you make sure you have enough in training to deal with any shortfalls that may come in the up years.”