A new software update prevented a third radar outage in the last two weeks at New Jersey's busy Newark airport when a telecommunications line failed again over the weekend, Transportation Secretary Sean Duffy said Monday.

The air traffic control mishap early Friday morning added to disruptions in recent days that have intensified concerns about safety at one of the busiest U.S. airports.

Radar screens at New Jersey's Newark Liberty International Airport went black again early Friday morning. The outage happened at 3:55 a.m. and lasted about 90 seconds, the Federal Aviation Administration said.

The air traffic controllers directing planes into the Newark, New Jersey, airport lost their radar Friday morning for the second time in two weeks.

A brief radar outage for Newark Liberty International Airport is the latest in a string of air traffic control failures tied to aging infrastructure.

There was another air traffic control outage in less than two weeks at the same Philadelphia facility that directs planes in and out of Newark Liberty International Airport on Friday morning.

Sunday's incident marks the fourth time in the past two weeks that technical problems have disrupted air traffic at Newark.

Because of the way airline networks are structured – particularly at United Airlines, which runs a major hub at Newark – delays and cancellations at that airport can have knock-on effects on flights scheduled to use the same planes later in the day on other routes.

Blank radar screens. Broken air traffic equipment. Flights in an out of Newark Airport delayed or canceled. Is it safe to fly here?

Travel woes at Newark Airport continued Monday after a weekend featuring another radar outage, a ground stop and dozens of flight cancellations and delays. The FAA announced Newark was operating on a ground delay program,