Operations are returning to normal after a runway equipment issues prompted ground stops at Newark Liberty and Hartsfield-Jackson Atlanta International airports Sunday, the Federal Aviation Administration announced.

Several times over the last year, Newark controllers lost radar or radio service, leaving them unable to talk with planes they were tracking.

Passengers traveling in and out of Newark at the end of the week shouldn't expect smooth sailing. Here's the latest at the New Jersey airport.

Similar to last summer, there is currently a nationwide shortage of air traffic controllers, which will “take time” to replenish, according to Transportation Secretary Sean Duffy.

“I equate a good, A-level, traffic controller that can handle a place like Newark, JFK, LAX, San Francisco, to a three dimensional chess player who can juggle a chainsaw, an axe, a sword, a razor blade with his eyes closed,” Aero Consulting Experts CEO and a former United pilot Ross Aimer told Fortune.

Caught in the middle of the issues at Newark is United Airlines, which is the most active airline at the New Jersey airport. While the problems lie with the FAA system, the airline is where people often aim their frustrations over cancellations and delays.

United Airlines Holdings Inc. expects flight reductions at Newark airport to linger through summer and into fall as the crucial travel hub struggles to recover from air traffic control glitches that have already disrupted hundreds of flights.