At times Monday evening, as few as three air traffic controllers per hour were lined up to monitor via radar the planes flying into and out of the airport, the Federal Aviation Administration said.

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.

The Federal Aviation Administration recently announced a three-year plan to upgrade air traffic control systems nationwide.

A reporter asked Duffy on Monday why the first Trump administration chose not to address the air traffic control system during his first term in office, noting that Duffy said it was a “decades-old” problem. However, Duffy’s answer left many users on social media scratching their heads.

The United States aviation industry continues to grapple with the worst air traffic controller shortage in nearly 30 years as a recent spate of incidents has thrust the high-stress profession into the spotlight.

One air traffic controller (ATC) and a trainee will operate every flight in and out of Newark between 6.30pm-9.30pm — despite 15 staffers being the standard requirement for a shift.