Prompted by a radar failure a week ago at Newark Liberty Airport, and a midair collision that killed 67 people in Washington D.C., President Donald Trump‘s administration announced an unprecedented program to rebuild the nation’s air traffic control system and recruit more air traffic controllers.

Several times over the last year, Newark controllers lost radar or radio service, leaving them unable to talk with planes they were tracking.

A deadly midair collision in January between a military helicopter and a commercial airliner, and several crashes since, have prompted officials to focus on fixing the nation’s outdated air traffic control system and hiring more controllers.