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

The Federal Aviation Administration said the radar at the facility in Philadelphia that directs planes in and out of Newark airport went black for 90 seconds at 3:55 a.m. Friday. That’s similar to what happened on April 28.

That first radar outage led to hundreds of flights being cancelled or delayed at the Newark airport in the past two weeks after the FAA slowed down traffic at the airport to ensure safety.

The FAA said earlier this week that it is installing new fiber optic data lines to carry the radar signal between its facilities in Philadelphia and New York.