The firings hit the FAA as federal officials have been raising concerns about an overtaxed and understaffed air traffic control system for years.

A union representing air safety personnel said it’s reviewing the fallout from a slew of firings late Friday that affected US Federal Aviation Administration employees, just a few weeks after the worst US civil aviation disaster in decades.

The firings are part of a cost-cutting drive by the Trump administration, that aims to drastically cut the federal workforce.