A failed backup telecommunications line led to a 90-second radar and radio outage last month that left air traffic controllers unable to see jetliners heading into Newark airport.

Duffy laid out an extensive plan to replace the nation’s outdated air traffic control system last week, including installing 4,600 new high-speed data connections and replacing 618 radars, but didn’t put a price tag on the plan other than to say it will cost billions.

Newark Liberty International Airport suffered another brief air traffic control outage Friday morning, the FAA confirmed.

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.

Transportation Secretary Sean Duffy plans to reduce the number of flights in and out of Newark Liberty International Airport for the "next several weeks."

Air traffic controllers in Denver had to scramble to use backup frequencies after their main communications lines went down for 90 seconds earlier this week in the latest Federal Aviation Administration equipment failure.

A staffing shortage, runway construction and deferred maintenance to crucial air traffic technology have made Newark Airport a national laughingstock.