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.

When the agency approved moving Newark air traffic controllers to Philadelphia, it said the odds of a dangerous communications breakdown was about 1 in 11 million.