A union representing air safety personnel said it’s reviewing the fallout from a slew of firings on February 14 that affected U.S. Federal Aviation Administration (FAA) employees, just a few weeks after the worst U.S. civil aviation disaster in decades. 

The National Air Traffic Controllers Association (NATCA), which represents air-traffic controllers, engineers and other aviation safety professionals, said in a statement that it “is analyzing the effect of the reported federal employee terminations on aviation safety, the national airspace system and our members.” 

Hundreds of FAA workers in their one-year probationary period began receiving messages about the firings after 7 p.m. New York time on February 14, according to the Professional Aviation Safety Specialists (PASS), a union that also represents federal employees at the aviation regulator. 

NATCA Region X employees, which include engineers, aircraft certification specialists, staff support specialists and aviation technical system specialists, were among those affected, according to the union. NATCA said it hasn’t received any reports of air-traffic controllers being included in the terminations.

The firings come at a critical time for air safety, with a number of high-profile crashes already this year, including the midair collision between a U.S. Army helicopter and an American Airlines regional jet that killed 67 people. 

“It’s a sad day for those who chose to serve in aviation safety and public service, only to have their careers cut short,” NATCA President Nick Daniels said in a post on the social media platform Instagram. “There is no evidence that these firings were about poor performance.” 

The action will place further strain on a workforce that’s already stretched thin, said PASS National President David Spero. 

“Staffing decisions should be based on an individual agency’s mission-critical needs,” he said. “To do otherwise is dangerous when it comes to public safety.” 

Representatives for the FAA and the U.S. Transportation Department didn’t immediately return a request for comment sent outside of normal business hours.