First came curses, then tears.On April 28 at about 1:27 p.m. local time, the air traffic controllers monitoring the skies above New Jersey’s Newark Liberty International Airport came face to face with their worst-case scenario: With radar and radio contact suddenly cut,

Recent chaos at Newark airport underscores just how tough it is to solve the nationwide shortage of air-traffic controllers that has been decades in the making. A brief outage during which controllers lost contact with flights in and out of the nation’s 12th busiest airport last week preceded widespread delays and cancellations that began this past weekend.

A veteran Newark airspace controller tells NBC News that a temporary blackout of both radios and radar systems from last week happened at least two other times since August. The Department of Transportation is set to unveil plans to overhaul a decades-old ATC system nationwide,