Whenever there’s an issue in the nation’s airspace, like the current string of delays and cancellations at Newark Liberty International Airport, air traffic controllers come under a microscope.

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

For the second time in two weeks, air traffic controllers directing planes into Newark Liberty International Airport lost radar access. The latest incident took place just before 4 a.m. Friday and lasted for about 90 seconds with screens going black during that time, according to the Associated Press.